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Supplementary Table from Inhibition of NF-κB DNA Binding Suppresses Myeloma Growth via Intracellular Redox and Tumor Microenvironment Modulation

Supplementary Figure from Inhibition of NF-κB DNA Binding Suppresses Myeloma Growth via Intracellular Redox and Tumor Microenvironment Modulation

Supplementary Data from Inhibition of NF-κB DNA Binding Suppresses Myeloma Growth via Intracellular Redox and Tumor Microenvironment Modulation

Multiple myeloma is a plasma cell malignancy that is still largely incurable, despite considerable progress in recent years. NF-κB is a well-established therapeutic target in multiple myeloma, but none of the currently available treatment options offer direct, specific pharmacologic targeting of NF-κB transcriptional activity. Thus, we designed a novel direct NF-κB inhibitor (IT848) as a drug candidate with strong potential for clinical translation and conducted comprehensive in vitro and in vivo mechanistic studies in multiple myeloma cell lines, primary multiple myeloma cells, xenograft models, and immunocompetent mouse models of multiple myeloma. Here, we show that IT848 inhibits NF-κB activity through inhibition of DNA binding of all five NF-κB subunits. IT848 treatment of multiple myeloma cell lines and patient samples inhibited proliferation and induced caspase-dependent and independent apoptosis. In addition to direct NF-κB inhibitory effects, IT848 treatment altered the redox homeostasis of multiple myeloma cells through depletion of the reduced glutathione pool, selectively inducing oxidative stress in multiple myeloma but not in healthy cells. Multiple myeloma xenograft studies confirmed the efficacy of IT848 as single agent and in combination with bortezomib. Furthermore, IT848 significantly improved survival when combined with programmed death protein 1 inhibition, and correlative immune studies revealed that this clinical benefit was associated with suppression of regulatory T-cell infiltration of the bone marrow microenvironment. In conclusion, IT848 is a potent direct NF-κB inhibitor and inducer of oxidative stress specifically in tumor cells, displaying significant activity against multiple myeloma cells in vitro and in vivo, both as monotherapy as well as in combination with bortezomib or immune checkpoint blockade.

Patients with high-risk multiple myeloma (hrMM) relapse after autologous stem cell transplantation (ASCT) with a median progression free survival (PFS) of 8-14 months without lenalidomide maintenance and 24-39 months with lenalidomide maintenance. We hypothesized that Pembro-Rd will prolong PFS post-ASCT in patients with hrMM compared to historical controls. This Phase II study enrolled hrMM patients with primary objective to assess the efficacy of the combination of Pembro-Rd for a total of 2 cycles and then an additional 2 cycles without dexamethasone. There were 12 evaluable subjects, as enrollment was stopped after an FDA hold. With a median follow-up of 50.7 months, the median PFS was 27.7 months. The PFS rates at years 1 and 2 are 90.9% and 63.6%, respectively. The most common adverse events were neutropenia (grade 1-3), cough, diarrhea and constipation, all grade 1 or 2. The PFS rate with fixed duration therapy was comparable to that seen with continuous dose lenalidomide, potentially offering a new post-ASCT therapeutic strategy. This article is protected by copyright. All rights reserved.

Autologous hematopoietic stem cell transplantation (ASCT) is a standard-of-care treatment for many hematologic malignancies. Progression of disease after ASCT is the primary cause of treatment failure. In this Phase Ib trial, we studied the safety and clinical effect of combined checkpoint inhibition therapy (CPIT) with ipilimumab and nivolumab as a consolidation strategy after ASCT for patients with high-risk diffuse large B cell lymphoma (DLBCL), mature T cell lymphoma (TCL), and multiple myeloma (MM). Starting at 14 to 28 days after ASCT, patients received ipilimumab (1 mg/kg i.v. on day 1 of weeks 1, 4, 7, 10, 16, and 22) and nivolumab (3 mg/kg i.v. on day 1 of weeks 1, 4, 7, 10, 12, 14, 16, 18, 20, 22, 24, and 26). Patients received a median of 5 doses of ipilimumab and 8 doses of nivolumab. Thirty-five patients were included in the intent-to-treat population. Ninety-four percent of the patients experienced immune-related adverse events (irAEs) of any grade. Ninety-seven percent of irAEs resolved spontaneously or after holding study drugs and instituting high-dose corticosteroid therapy. Progression-free and overall survival at 18 months post-ASCT for each disease cohort were 85.7% and 100% for primary refractory DLBCL, 28.6% and 57.1% for relapsed DLBCL, not evaluable and 80% for frontline TCL, 25% and 75% for relapsed TCL, 57.1% and 87% for high-risk transplant-naive MM, and 40% and 100% for MM relapsed within 3 years of first ASCT. We conclude that combined CPIT appears to be tolerable as a consolidation strategy after ASCT and in addition to the potential clinical efficacy observed in some subsets of disease, T cell receptor repertoire, T regulatory cell phenotype, and gut microbiota profiles provide a biologic rationale warranting further study of this approach.

Here, we report on a phase IIa study to determine the intubation rate, survival, viral clearance, and development of endogenous Abs in patients with COVID-19 pneumonia treated with convalescent plasma (CCP) containing high levels of neutralizing anti–SARS-CoV-2 Abs. Radiographic and laboratory evaluation confirmed all 51 treated patients had COVID-19 pneumonia. Fresh or frozen CCP from donors with high titers of neutralizing Abs was administered. The nonmechanically ventilated patients (n = 36) had an intubation rate of 13.9% and a 30-day survival rate of 88.9%, and the overall survival rate for a comparative group based on network data was 72.5% (1625/2241). Patients had negative nasopharyngeal swab rates of 43.8% and 73.0% on days 10 and 30, respectively. Patients mechanically ventilated had a day-30 mortality rate of 46.7%; the mortality rate for a comparative group based on network data was 71.0% (369/520). All evaluable patients were found to have neutralizing Abs on day 3 (n = 47), and all but 1 patient had Abs on days 30 and 60. The only adverse event was a mild rash. In this study on patients with COVID-19 disease, we show therapeutic use of CCP was safe and conferred transfer of Abs, while preserving endogenous immune response., Patients with COVID-19 pneumonia receiving high-titer convalescent plasma showed antibody transfer with preservation of endogenous production, and database survival comparison is promising for the early group.

OBJECTIVESTo determine the rate of intubation, overall survival, viral clearance, and the development of endogenous antibodies in patients with COVID-19 pneumonia treated with convalescent plasma containing high levels of neutralizing anti-SARS-CoV-2 antibodies. We also aimed to describe the laboratory parameters of the plasma products.DESIGNThis was a phase IIa, single institution, prospective study in adults hospitalized with SARS-CoV-2 pneumonia.SETTINGHackensack University Medical Center, a 770-bed research and teaching hospital located in Bergen County NJ, 11 km from New York City. The study was conducted between April 15 and June 18, 2020.PARTICIPANTS47 hospitalized adult patients were treated: 32 in the non-mechanically ventilated group and 15 in the mechanically ventilated group. All patients had confirmed SARS-CoV-2 pneumonia by radiographic and laboratory evaluation.INTERVENTIONFresh or frozen convalescent plasma from donors with high titers of viral neutralizing antibodies was administered.MAIN OUTCOME MEASURESIncidence of intubation, overall survival, and discharge rate of patients divided in cohorts based on severity of disease. Description of infused plasma characteristics. Evaluation of recipients’ pre-treatment viral immunity, immunity transfer from convalescent plasma administration, and late immunity 30 and 60 days after treatment. Rates of viral clearance by nasopharyngeal PCR at 10 and 30 days. Outcomes of patients with no pre-treatment immunity. Survival comparison with institutional data for each cohort.RESULTSAnalysis for the non-mechanically ventilated patients showed an intubation rate of 15.6% (95% CI: 5.3%-32.8%) and a day-30 survival rate of 87.5% (28/32; 95% CI:70.2%-96.4%). The overall survival for a comparative group based on institutional data was 66% (675/1023; p=0.012). The rates of negative nasopharyngeal swab by PR-PCR on day+10 and +30 post treatment were 42.9% (95% CI: 24%-63%) and 78% (95% CI: 56%-93%) respectively. Patients mechanically ventilated had a day-30 mortality of 46.7% (95% CI:21.3%-73.4%); the mortality for a comparative group based on institutional data was 68.5% (217/317; p=0.093). The rates of negative nasopharyngeal swab by PR-PCR at day+10 and +30 was 85.7% (95% CI: 42-100%; n=7) and 100% (95% CI: 63-100%; n=8). Seven patients (15%) had no pre-infusion immunity, and all were found to have anti-SARS-CoV-2 neutralizing titers three days post infusion. All evaluable patients were found to have neutralizing antibodies on day+30 (n=30) and on day+60 (n=12) post treatment. There was no difference in outcomes within the ranges of high antiviral neutralizing titers used, mostly greater than 1:1000. There was also no difference between fresh or frozen plasma. The only adverse event was a mild rash in one patient.CONCLUSIONIn this study of adult patients hospitalized with SARS-CoV-2 pneumonia, convalescent plasma was safe and conferred effective transfer of immunity while preserving endogenous immune response. Intubation rates, survival rates compared with institutional data, and viral clearance rates, support the continued evaluation of this antiviral modality.STUDY REGISTRATIONClinicalTrials.gov NTC04343755

BackgroundMapping of allele-specific DNA methylation (ASM) can be a post-GWAS strategy for localizing regulatory sequence polymorphisms (rSNPs). However, the advantages of this approach, and the mechanisms underlying ASM in normal and neoplastic cells, remain to be clarified.ResultsWe performed whole genome methyl-seq on diverse normal cells and tissues and three types of cancers (multiple myeloma, lymphoma, glioblastoma multiforme). After excluding imprinting, the data pinpointed 15,114 high-confidence ASM differentially methylated regions (DMRs), of which 1,842 contained SNPs in strong linkage disequilibrium or coinciding with GWAS peaks. ASM frequencies were increased 5 to 9-fold in cancers vs. matched normal tissues, due to widespread allele-specific hypomethylation and focal allele-specific hypermethylation in poised chromatin. Cancers showed increased allele switching at ASM loci, but disruptive SNPs in specific classes of CTCF and transcription factor (TF) binding motifs were similarly correlated with ASM in cancer and non-cancer. Rare somatic mutations affecting these same motif classes tracked with de novo ASM in the cancers. Allele-specific TF binding from ChIP-seq was enriched among ASM loci, but most ASM DMRs lacked such annotations, and some were found in otherwise uninformative “chromatin deserts”.ConclusionsASM is increased in cancers but occurs by a shared mechanism involving disruptive SNPs in CTCF and TF binding sites in both normal and neoplastic cells. Dense ASM mapping in normal plus cancer samples reveals candidate rSNPs that are difficult to find by other approaches. Together with GWAS data, these rSNPs can nominate specific transcriptional pathways in susceptibility to autoimmune, neuropsychiatric, and neoplastic diseases. Custom genome browser tracks with annotated ASM loci can be viewed at a UCSC browser session hosted by our laboratory (https://bit.ly/tycko-asm)

e20518 Background: Gut microbiome dysbiosis is correlated with graft-versus-host disease (GVHD) in allogeneic stem cell transplant (allo-SCT) patients. In the allo-SCT population, antibiotics have been associated with increased risk for GVHD mortality and relapse due to loss of gut obligate anaerobes . It has been shown that antibiotics may negatively impact the efficacy of checkpoint inhibitors for patients with solid tumors. Based on these studies, we performed a retrospective analysis to determine if antibiotic treatment affects outcomes of multiple myeloma (MM) patients after autologous SCT (ASCT). Methods: This is a single institution retrospective study at Hackensack University Medical Center. A list of consecutive MM patients treated from 1/2012 to 12/2015 was obtained and an electronic medical record review of the first 217 who received ASCT was performed. Baseline characteristics, treatment history, transplant course and antibiotic treatment (including β-lactams, fluoroquinolones, macrolides, metronidazole, and vancomycin) were reviewed. Prophylactic antibiotics were excluded. Response was defined using the IMWG criteria. Median progression free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Log rank tests were used to compare the difference in survival between stratified groups. The LASSO cox regression analysis method was used for multivariate analyses of PFS and OS. Results: Of the 217 patients, 205 patients were available for analysis. Median age at ASCT was 61. β-lactams were associated with decreased median PFS (1.95 vs 4.77 years (yrs), p < 0.01) and decreased median OS (7.51 vs 13.45 yrs, p = 0.01). Multivariate analysis adjusting for lasso-selected age, gender, complete remission (CR) after ASCT, and ISS demonstrated independent progression risk associated with β-lactam use (HR = 2.00, 95% CI, 1.28–3.12, p < 0.01). β-lactams were associated with worse OS in multivariate analysis adjusting for lasso-selected age, gender, CR after ASCT and high risk cytogenetics (HR = 1.89, 95% CI, 1.07–3.40, p = 0.03). Conclusions: In this preliminary study, β-lactams predicted for decreased PFS and OS compared to patients who did not receive β-lactams in MM patients undergoing ASCT. The study was limited by its retrospective nature but demonstrates one of the first evaluations of antibiotic effect on the ASCT population in MM. Prospective studies evaluating the impact of antimicrobials on patient outcomes and the gut microbiome are ongoing.

Background: The discovery that gut microbial dysbiosis correlated with prognosis, immune reconstitution and development of graft-versus-host disease (GVHD) in patients undergoing allogeneic stem cell transplantation (allo-SCT) highlights the clinical relevance of the gut microbiome in shaping anti-tumor immune responses. Treatment of allo-SCT patients with antibiotics has recently been associated with increased GVHD mortality (Routy et al. 2017). Based on these studies and the association of distinct gut bacteria with increased efficacy to PD-1 blockade in patients with solid tumors (Derosa et al. 2018), we performed a retrospective analysis to determine if infection treated with antibiotics affected the outcomes of multiple myeloma (MM) patients after autologous SCT (ASCT). Methods: A list of all MM patients treated at our institution between January 2012 through December 2015 was obtained and 1095 patients were identified. A comprehensive review of the electronic medical record (EMR) of the first 142 who received ASCT was performed. Information was collected from diagnosis to the date of last contact. Baseline characteristics, treatment history, transplant course, antibiotic treatment, and infection severity using common terminology criteria for adverse event (CTCAE) version 4 were reviewed. Prophylactic antibiotics were excluded. Response was measured and defined using the International Myeloma Working Group Criteria. Progression free survival (PFS) and overall survival (OS) were estimated using log rank tests. Cox hazard stepwise regression model examined for multiple factors affecting PFS and OS using the Akaike information criterion. Results: Of the 142 patients, 93 (65%) were Durie Salmon (DS) III, 20 (14%) were Revised International Staging System (R-ISS) III, 44 (31%) had high-risk cytogenetics, and 76 (54%) were male. The median age at diagnosis was 60. Although there was a similar frequency of DS III (67% vs 61%) and high-risk cytogenetics (35% vs 25%) among patients in the antibiotic and non-antibiotic treated groups, there was an over-representation of R-ISS 3 (19% v 4%) patients in the antibiotic-treated group. Treatment with antibiotics was associated with decreased median PFS (2.38 vs 6.58 years (yrs), p =0.00003) (Figure 1a) and decreased median OS (7.43 vs 17.39 yrs, p = Multivariate analysis demonstrated progression risk associated with beta-lactam use (HR-2.25, 95% CI, 1.31 - 3.85, p = 0.003), and DSS III (HR-2.28, 95% CI, 1.23 - 4.21, p = 0.009). Multivariate analysis demonstrated increased mortality associated with antibiotic treatment (HR-5.70, 95% CI, 1.34 - 34.29, p = 0.019) and decreased mortality risk with age younger than 65 (HR-0.24, 95% CI, 0.07 - 0.81, p = 0.022). For both PFS and OS, there was no statistical significance demonstrated in multivariate analysis for gender, fluoroquinolone treatment, high risk cytogenetics, R-ISS 3, or CTCAE grade. Conclusion: In this preliminary study, antibiotic use and infection severity predicted for decreased PFS and OS compared to patients who did not receive antibiotics in MM patients undergoing ASCT. Treatment with at least 2 classes of antibiotics-fluoroquinolones and beta-lactams, predicted for decreased PFS and OS. Multivariate analysis showed increased progression risk with beta lactams and DSS III as well as increased mortality risk with antibiotic treatment and advanced age. The study was limited by its relatively small sample size, retrospective nature, and the high correlation among infection and antibiotic groups that affected the multivariate analysis. Work is underway at our institution to further elucidate the impact of antibiotics on microbial diversity and patient survival. Disclosures Goldberg: COTA: Equity Ownership; Bristol-Myers Squibb: Consultancy; Cancer Outcomes Tracking and Analysis (COTA) Inc.: Equity Ownership. Rowley:Allergan: Equity Ownership; Fate Therapeutics: Consultancy. Siegel:Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb Company: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Biran:Merck: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Bristol Meyers Squibb: Research Funding.

Introduction: Patients with high-risk multiple myeloma (HRMM) who have undergone autologous stem cell transplant (ASCT) will inevitably relapse and have a progression free survival (PFS) ranging from 8-14 months (Gaballa et al, American Journal of Hematology, 2016) and 24-39 months while on lenalidomide (Len) maintenance therapy (Jackson et al, The Lancet Oncology, 2019). Unlike in solid tumors, PD-1 blockade has no single agent activity in relapsed and refractory multiple myeloma (MM) patients suggesting that immune stimulating agents, immunomodulatory agents (IMiDs), such as lenalidomide (Len) or pomalidomide (Pom) are necessary in combination with anti-PD-1 blockade to increase depth and duration of response post-ASCT. The Keynote-023 study revealed an overall response rate (ORR) of 76% with the combination of pembrolizumab (Pem), Len and dexamethasone (Dex). Similarly, the Keynote 135 study using the combination of Pem, Pom, and Dex revealed an ORR of 60%. Unfortunately, the phase III studies comparing an IMiD vs Pem with the IMiD upfront at the early relapsed setting were halted because of increased deaths on the Pem arm and a decreased median PFS. With our Phase II study currently on clinical hold by the FDA, we are presenting here the 2-year follow-up of the original patient cohort including some preliminary safety and efficacy data of Pem-Len-Dex in HRMM patients as post-ASCT consolidation (NCT02906332). Methods: Patients with HRMM who have undergone induction therapy followed by single or tandem melphalan-based ASCT were considered eligible 2-6 months post ASCT. HRMM criteria are defined by any of the following: ISS stage 3; del 13q by cytogenetics; FISH with 1q amplification, 1p deletion (del), p53 del, t(4;14), t(14;16), t(14;20), hypodiploidy; or a high-risk gene expression profile score. Patients were excluded if they had progression of disease at time of screening or if there was evidence of organ dysfunction. Patients received Pem 200 mg IV at day 1;Len 25 mg po daily at days 1-14; and Dex 40 mg daily at days 1,8,15 of a 21-day cycle for a total of 2 cycles and then an additional 2 cycles of Pem + Len without Dex at the same dose and frequency. Survival outcomes post-ASCT were measured using the log-rank test. Results: Of 15 patients screened, 12 received at least one dose of therapy and were deemed evaluable. One patient withdrew consent and did not follow up after cycle 2. Baseline characteristics are shown in Table 1. Thirty-three percent were ISS 3, 66.7% had a p53 deletion by FISH, 41.6% received induction Bortezomib-Len-Dex; 33% received induction Carfilzomib-Len-Dex, and the remaining 24.9% received other bortezomib-based induction. Best ORR during the 2 year follow up showed 8 patients (73%) achieving stringent complete remission, 2 patients (18%) showing complete remission and 1 (9%) achieving very good partial remission. Table 2 shows best response to treatment by cycle of therapy. Table 3 shows best response during follow-up visits, which were 3 months apart. Of the 11 patients who completed therapy, 8 had minimal residual disease (MRD) status assessed and among them, 7 were MRD negative by flow cytometry, tested 30 days after the fourth cycle. With a median follow-up of 32.2 months, median PFS was 27.6 months. The PFS rates at 1 year and 2 year are 91.3% and 65.2%, respectively. All patients had adverse events (AEs), AEs were attributed to Pem, Len, or Dex rather than from ASCT. Of the 90 AEs that were reported, 5.6% were grade 3 and 94% were grade 1 or 2 (Table 3). The most common hematologic AE was neutropenia (41.7%), with 3 pts (25%) grade 1 and 2, and 2 pts (16.6%) grade 3. The most common non-hematologic AEs were intermittent constipation (16.6%), diarrhea (16.6%), fatigue (8.3%), and increased ALT (8.3%) and were graded as 1 or 2. Non-hematologic grade 3 AEs occurred in 2 pts and included hypoxia and maculopapular rash. There was 1 serious AE, H. influenza pneumonia requiring inpatient admission, which was not considered to be related to Pem. Conclusions: The combination of Pem, Len, and Dex given to HRMM patients in the post-ASCT consolidation setting is well tolerated. In comparison to historical controls of HRMM patients post-ASCT with a median PFS of 8-14 months, the PFS rates of 91.3% and 65.2% at 1 and 2 year post-ASCT respectively suggest an efficacy signal for the use of Pem, Len, and Dex as post-ASCT consolidation. Larger prospective studies are needed to validate these results. Disclosures Siegel: Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb Company: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Rowley:Allergan: Equity Ownership; Fate Therapeutics: Consultancy. Biran:Amgen: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Bristol Meyers Squibb: Research Funding.

Background: AlloHCT is a potentially curative treatment for patients with acute myeloid leukemia (AML) and other myeloid malignancies (MM), however has a 40% relapse rate. The 2-year post-relapse survival rate is less than 20%; sustainable remissions are rare. Multiple strategies to mitigate relapse have been employed with variable degrees of success. An as yet untested approach involves manipulation of the T-cell milieu in the post-alloHCT setting using CI. Preclinical animal models of tumors have shown that blockade of PD-1 by monoclonal antibodies(mAbs) can enhance the anti-tumor immune response and result in tumor rejection, suggesting that host mechanisms limit the antitumor response. A murine model of an anti-PD-1 mAb given at the time of transplant showed that PD-1/PD-L1 interactions decrease acute GVHD, but increase chronic GVHD suggesting that PD-1 pathway modulation may provide unique opportunities for stimulating immune regulation post-alloHCT. Use of ipilimumab (I) to treat post-transplant MM resulted in a complete response rate of 42% and decreased the Treg/Tconv cell ratio, consistent with enhancement of the graft-versus-tumor effect. The CPIT-001 Trial demonstrated the feasibility and safety of combined CI with I and nivolumab (N) as consolidation following autologous stem cell transplantation (ASCT) for high-risk hematological malignancies as well as a 67% PFS rate at 18 months post-ASCT, a significant improvement as compared with historical data. Study Design: The study employs a 3x3 design with intrapatient dose escalation. Patients will alternately be assigned to receive either N or I as a single agent. If the safety endpoint is met for each group, enrollment to the combination CI group will open. See table 1 for dosing. For all Groups, intrapatient dose escalation will be utilized. If the patient tolerates 28 days of treatment, he/she will be escalated to the next dose level and the next patient will be enrolled. Enrollment must occur within 60 days prior to HCT conditioning to allow for collection of baseline samples. Patients will start CI therapy 60 to 100 days after stem cell infusion when acute GvHD is adequately controlled on a prednisone dose of 20 mg daily or less, organ function, and peripheral counts are adequate. Key inclusion criteria at study start up included patient age 75 years or less with high risk AML or MDS undergoing alloHCT with a matched-related or 10/10 unrelated donor who were receiving non-myeloablative conditioning. Bone marrow aspiration will be performed for response evaluation approximately every 3 months post CI initiation. The primary objective is to assess the safety of CI in this patient population. Secondary objectives include efficacy, assessment of blood immune reconstitution, phenotype and TCR repertoire by sequencing, assessment of tumor site immune phenotype, TCR repertoire and PD-L1/2 expression both prior to alloHCT conditioning and at relapse. The tertiary objective is to identify specific intestinal microbial strains associated with improved outcomes in alloHCT patients treated with CI. Microbial composition in stool samples of patients will be analyzed at screening, at engraftment, at various time points post-transplant, and at time of relapse, as it occurs. Study Experience Thus Far: The study opened to accrual in May of 2017. Four patients have signed informed consent. Two patients have been treated with CI. One patient withdrew consent prior to treatment and a second patient is currently status post alloHCT, but has not yet reached day 60. One patient received 2 doses of N and the second patient received 1 dose of I. Accrual to trial has been slower than anticipated. A detailed analysis of the patient screening log was completed. It was determined that 139 patients had been screened for trial. Major reasons for being ineligible included a diagnosis of ALL (34 patients; 24%), use of a haploidentical donor (30 patients; 22%), use of a full dose conditioning regimen (14 patients; 10%), diagnosis of CML (12 pateints; 10%), age greater than 75 (12 patients; 9%), diagnosis of CMML (12 patients; 9%). Following this analysis, an amendment was filed to include patients receiving haplo identical transplant and/or myeloablative conditioning, and to expand diagnosis to include all MM including CMML, CML blast crisis, and myelofibrosis. Disclosures Koprivnikar: Amgen: Speakers Bureau; Pfizer: Honoraria; Abbvie: Speakers Bureau; Novartis: Speakers Bureau. McCloskey:Jazz: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Takeda: Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Abbvie: Speakers Bureau; Novartis: Speakers Bureau. Rowley:Fate Therapeutics: Consultancy; Allergan: Equity Ownership. OffLabel Disclosure: Nivolumab - immunomodulation Ipilimumab - immunomodulation

Rationale: ASCT remains a standard-of-care as consolidation or salvage for multiple myeloma (MM), post-salvage consolidation for Diffuse Large B-Cell Lymphoma (DLBCL) and upfront consolidation or salvage for Peripheral T-Cell Lymphomas (PTCL) Pts with high-risk disease still show poor outcome and frequent progression within the first 18 months. Maintenance strategies post ASCT, particularly in lymphomas, have failed to show benefit, underlining the need for novel approaches to help disease control following ASCT. We have previously reported on the preliminary safety and efficacy of checkpoint inhibitor consolidation with Ipi and Nivo following ASCT trying to take advantage of the immunological milieu during post-ASCT recovery (Skarbnik et al., ASH 2017). Here we present updated data from our Phase I CPIT-001 trial. Methods: Pts with high-risk DLBCL, PTCL or MM (as defined in Table 1, divided in cohorts) were eligible if they experienced at least stable disease after most recent salvage therapy (NHL, PTCL or relapsed MM) or after induction therapy for high-risk MM. Pts were enrolled prior to ASCT, starting in July 2016. All pts with DLBCL/PTCL received BEAM (carmustine 300 mg/m2 day -6, etoposide 200 mg/m2 and cytarabine 200 mg/m2 days -5 to -2, melphalan 140 mg/m2 day -1) as conditioning regimen for ASCT, all pts with MM received melphalan 200 mg/m2 on day -1 For pts who achieved appropriate hematologic recovery (ANC >800/mm3 and platelets > 20,000/mm3), Ipi/Nivo were started between days 14 and 28 post ASCT. The infusion schedule was: Ipi: 1 mg/kg; 6 doses Weeks 1, 4, 7, 10, 16, 22Nivo: 3 mg/kg; 12 doses Weeks 1, 4, 7, 10, 12, 14, 16, 18, 20, 22, 24, 26 Primary objectives were: Safety profile evaluation; PFS and OS at 18 months (PFS18 and OS18). Cox proportional hazards regression was utilized to determine predictors of outcome. Results: 31 pts received at least one dose of Ipi/Nivo following ASCT and were included in the intent-to-treat population. Median follow up for the whole cohort is 16 months. As of February 2018, the FDA has halted all studies including checkpoint inhibitors for pts with MM. At that time, only one pt with MM was actively receiving Ipi/Nivo, which was then discontinued. At 18 months post ASCT, estimated PFS for the entire cohort was 67% and OS was 84% (Figures 1 and 2). Disease-specific PFS18 and OS18 are described in Table 2. At study entry, 48% of pts were in CR (NHLs) or stringent CR (sCR, MMs). At most recent follow-up (range 2-25 months) 71% of pts were in CR (NHL) or sCR (MM). Disease status at study entry (i.e. CR vs 65% of pts developed immune-related adverse events (irAEs) grade 2 or higher, requiring treatment with systemic steroids. Most common irAEs of any grade were: colitis (58%), rash (48%), thrombocytopenia (45%), anemia (45%) and transaminitis (32%). One pt (3%) died from complications of pneumonitis related to study drugs. All other irAEs resolved. Median time from 1st Ipi/Nivo to development of irAEs was 4 weeks. Median time to improvement to Grade 1 or baseline was 1 week after high-dose steroids were initiated. Treatment-related AEs of any grade that led to discontinuation of Ipi/Nivo occurred in 6 pts (19%). Development of irAEs, use of steroids or length of steroid-exposure did not correlate with PFS or OS. Conclusion: At 18 months post-ASCT, PFS for pts with high-risk hematological malignancies is 67%. This number underscores the potential for longer remissions by associating checkpoint inhibition with ASCT. For patients in the transplant-naïve MM with high-risk cytogenetics cohort, the 71% PFS18 (fig 3) is particularly striking, when compared to median PFS of 13-15 months in previous reports of ASCT alone in this patient population (Sonneveld et al, Blood 2016). In addition, the primary-refractory DLBCL population (43% of which were not in CR at time of ASCT) presented with a PFS18 of 83% (fig 4), while the reported PFS18 for this patient population with ASCT alone is 50% (Crump et al, Blood 2017). The cohort of pts with DLBCL relapsed within 1 year of induction had the poorest outcomes, possibly related to these pts being the most heavily pretreated in the whole cohort (median of 3 prior lines of therapy), with 57% of pts in this cohort refractory to most recent line of therapy. The manageable toxicity profile, coupled with the encouraging efficacy outcomes warrant further evaluation of this approach in a Phase II trial, which is currently planned. Disclosures Skarbnik: Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Honoraria, Speakers Bureau. Munshi:Kite: Speakers Bureau. Siegel:BMS: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria; Merck: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Speakers Bureau. Feldman:Pharmacyclics: Speakers Bureau; KITE: Speakers Bureau; Portola: Research Funding; Celgene: Speakers Bureau; Seattle Genetics: Research Funding, Speakers Bureau; Johnson and Johnson: Speakers Bureau; Janssen: Speakers Bureau. Biran:BMS: Research Funding; Amgen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Merck: Research Funding. Atkins:BMS: Consultancy; Merck: Consultancy.

BACKGROUND: High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is now the standard of care for newly diagnosed MM and refractory DLBCL patients. However, relapse remains the primary cause of morbidity and mortality, and thus, new therapeutic strategies are required to improve overall survival. In recent years, treatment with immune checkpoint inhibitors Nivolumab (Nivo), an anti-PD1 mAb, or Ipilimumab (Ipi), an anti-CTLA4 mAb, as single agents have achieved durable responses in patients with advanced solid tumors, and may prove to be useful for the treatment of hematological malignancies. RATIONALE: In patients with advanced cancers including melanoma and Hodgkin's lymphoma, combined Nivo/Ipi therapy resulted in superior clinical efficacy compared to monotherapy. The immediate post-ASCT period provides an ideal window to introduce combined therapy because disease burden is at a minimum and the conditioning-induced inflammatory environment may enhance checkpoint inhibition effects on anti-tumor immune responses. OBJECTIVE: To study the Treg and memory T cell compartments in the peripheral blood (PB) of high-risk MM and DLBCL patients, within the first 12 wks post-ASCT, during a Nivo/Ipi treatment regimen. STUDY DESIGN: The interim longitudinal analyses of early Treg and memory T cell profiles was performed on PB sampled from patients up to 12 wks post-ASCT and treated with Nivo + Ipi, with a focus on four patient disease groups: A=de novo DLBCL; B=recurrent high-risk DLBCL; E=de novo high-risk MM; and F=recurrent MM. PB samples obtained from patients at initial screening (PB0) served as a baseline. The MM patients underwent conditioning with CDE or melphalan 200 mg/m2 followed by mobilization with filgrastim, apheresis, and hematopoietic progenitor cell reinfusion. Lymphoma patients were conditioned with BEAM. Starting 2-4 wks later, they were administered double therapy (Ipi 1mg/kg; 6 doses at wks 1, 4, 7, 10, 16, 22 and Nivo 3 mg/kg; 12 doses at wks 1, 4, 7, 10, 12, 14, 16, 18, 20, 22, 24, 26). PB was collected just prior to any treatment at various time points. RESULTS: Table 1 summarizes the mean ± sem % of total lymphocytes for the Treg compartment at all time points. The % of naïve (RO-) Tregs was decreased up to wk 12 in all the groups (A; PB0 0.17; PB12 0.05), (B; PB0 0.16; PB12 0.03), (E; PB0 0.40; PB12 0.02), (F; PB0 0.32; PB12 0.00); and in memory (RO+) Tregs, except for F, (A; PB0 0.86; PB12 0.48), (B; PB0 0.16; PB12 0.03), (E; PB0 1.26; PB12 0.39), (F; PB0 0.32; PB12 0.53). Similar results were observed in the absolute numbers of Tregs for all groups. In the memory T cell compartment, summarized in Table 2, by wk 12, the % effector memory (EM) CD4+ T cells increased in the A and F groups, but were decreased in B and E (A; PB0 4.69; PB12 5.33), (B; PB0 4.12; PB12 2.45), (E; PB0 5.69; PB12 2.99), (F; PB0 3.27; PB12 5.14). In contrast, EM CD8+ T cells in the A and E groups decreased in this compartment (A; PB0 2.91; PB12 1.49) (E; PB0 16.57; PB12 0.46), while the B group markedly increased by wk 12 (B; PB0 0.65; PB12 17.91), and the F group remained equivalent (F; PB0 0.18; PB12 0.24). Moreover, the centralmemory (CM) CD4+ T cell compartment was moderately decreased in all groups, except the F group (A; PB0 2.59; PB12 1.04), (B; PB0 4.12; PB12 2.5), (E; PB0 5.6; PB12 0.82), (F; PB0 1.62; PB12 1.5). Finally, the % of CD4+CCR7+RO-terminally differentiated (TEMRO-) cells was decreased in A, E and F, but not in B, groups (A; PB0 0.80; PB12 0.20), (B; PB0 0.23; PB12 0.26), (E; PB0 1.82; PB12 0.23), (F; PB0 0.66; PB12 0.43). In contrast, the % of CD8+CCR7+RO- TEMRO- cells was increased in B (PB0 1.52; PB12 11.73) and E (PB0 0.76; PB12 2.93), but not in A (PB0 3.12; PB12 2.08) and F (PB0 0.02; PB12 0.0.00) groups. Similar trends were observed with the absolute numbers of subsets. CONCLUSIONS: Combined Nivo + Ipi therapy administered early post-ASCT exhibited a trend of decreased presence of naïve Tregs, in all groups, and memory Tregs in all groups but F by wk 12. In addition, there was an increased trend in the presence of CD8+ EM T cells in group B, and of the CD4+ EM T cells in groups A and F. Increased EM activity could potentially enable the immune system to continue to target tumor cells while in therapy. Finally, there was an increased trend in both CD4+ and CD8+ TEMRO- T cells in group B, which were consistent with the notion of exhaustion of longer surviving EM T cells. Disclosures Munshi: Kite: Speakers Bureau. Atkins:Merck: Consultancy; BMS: Consultancy. Biran:Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Merck: Research Funding; BMS: Research Funding; Amgen: Consultancy, Speakers Bureau. Siegel:Takeda: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Merck: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria; Novartis: Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau. Feldman:Portola: Research Funding; Seattle Genetics: Research Funding, Speakers Bureau; Johnson and Johnson: Speakers Bureau; KITE: Speakers Bureau; Pharmacyclics: Speakers Bureau; Janssen: Speakers Bureau; Celgene: Speakers Bureau. Skarbnik:Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Speakers Bureau.

Engraftment syndrome (ES) is a frequently occurring complication in patients receiving autologous stem cell transplantation (ASCT) for the treatment of multiple myeloma and various types of non-Hodgkin lymphomas. This clinical entity presents as skin rashes, diarrhea, non-infectious fevers and capillary leak syndrome in the peri-engraftment period coinciding with neutrophil recovery. The etiology and risk factors contributing to the development of ES remain unclear. The goal of the present study was to analyze the cytokine composition of the grafted mobilized peripheral blood stem cell product as well as serum cytokine levels in patients undergoing ASCT for the treatment of multiple myeloma and lymphoma. Cytokines were analyzed in the apheresis stem cell product, as well as patient plasma 1-2 days pre-transplant, 12 days post-transplant, and 2-4 months post-transplant using the Luminex xMAP multiplex cytokine platform. The concentrations of 29 cytokines from 38 patients were analyzed. Seventeen of these patients were diagnosed with engraftment syndrome using the Spitzer criteria. Patients who developed ES were shown to have significantly elevated levels of IL-1 receptor antagonist (IL-1Ra) in the apheresis product as compared to patients that did not develop ES (31,033 vs. 6015 pg/ml; p=0.028). IL-1Ra levels were not significantly different at other time points. IL-1Ra competes with IL-1α and IL-1β for binding to the IL-1 receptor thus acting as an antagonist to this proinflammatory cytokine. The gene encoding IL-1Ra has a tandem repeat sequence resulting in polymorphic alleles in the population with varying number of repeats. The allele containing 2 repeats, IL1RN*2, has been associated with various inflammatory diseases including Sjogren's syndrome, ulcerative colitis, Crohn disease, psoriasis, multiple sclerosis, and SLE. We performed PCR on the DNA isolated from the PBMCs of these patients to determine if patients with elevated IL-1Ra possessed the IL1RN*2 allele. Results did not find any correlation between IL-1RN*2 allele and elevated IL-1Ra levels in the apheresis samples. In addition, levels of the chemokine IFN-gamma-induced protein 10 (IP-10/CXCL10) were found to be significantly higher in patients diagnosed with ES at both the day 12 post-transplant (1089 vs. 689 pg/ml; p=0.022) and 2-4 month post-transplant time points (1768 vs. 922 pg/ml; p Disclosures Siegel: Takeda: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Merck: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria. Biran:Takeda: Consultancy, Speakers Bureau; Merck: Research Funding; Amgen: Consultancy, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; BMS: Research Funding. Vesole:Amgen: Speakers Bureau; Takeda: Speakers Bureau. Feldman:Janssen: Speakers Bureau; Pharmacyclics: Speakers Bureau; Celgene: Speakers Bureau; Johnson and Johnson: Speakers Bureau; Seattle Genetics: Research Funding, Speakers Bureau; KITE: Speakers Bureau; Portola: Research Funding. Skarbnik:Novartis: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

BACKGROUND: High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is now standard of care for newly diagnosed patients with multiple myeloma (MM) and is used for some forms of non-Hodgkin lymphoma, providing improved outcomes. ASCT has been associated with a high incidence of engraftment syndrome (ES), which clinically presents as skin rashes, diarrhea, non-infectious fevers, and capillary leak syndrome in the peri-engraftment period. ES can be a severe and potentially lethal complication in patients who do not respond to corticosteroid therapy. RATIONALE: Prior to stem cell collection, MM and lymphoma patients are typically exposed to chemotherapy and immunomodulatory agents in order to reduce the cancer cell burden and other drugs to mobilize stem cells. It has been hypothesized that these agents may be involved with ES development in that they can disrupt the balance of immune regulatory and effector cell subsets. OBJECTIVE: To analyze T cell activation/memory and Treg cell compartments as well as classical, intermediate, and non-classical monocytes in the autologous apheresis product of MM and lymphoma patients undergoing ASCT. STUDY DESIGN: Samples were collected under IRB approval from 28 patients undergoing ASCT for the treatment of MM (n=21) or lymphoma (n=7) at the time of peripheral blood stem cell collection (the apheresis product); Peripheral blood mononuclear cells (PBMC) were isolated by sucrose gradient centrifugation and frozen until needed for phenotyping by multi-parametric flow cytometry. MM patients were conditioned for ASCT with melphalan alone (n=14) or in combination with bortezomib (n=7); lymphoma patients received conditioning with BEAM (carmustine, etoposide, cytarabine, and melphalan) chemotherapy. RESULTS: Of the 28 patients undergoing ASCT, 10 (35.7%) developed ES within the first four weeks post-transplantation. We analyzed by flow cytometric phenotyping the following immune cell subsets: overall CD4/CD8 T cells, CD4/CD8 naïve and memory cells, HLA-DR expression on memory T Cells, memory CD4 Tregs, as well as overall classical, intermediate, and non-classical monocytes. The absolute numbers (PBMC conc. (cell/ml of blood) x (% of cells in PBMC/100) and percentage population (# of events in population gate/# of total PBMC events x 100) data were transformed with log and square root functions, respectively. All data were tested for normality with a Shapiro-Wilks online test and p-values were obtained by performing an unpaired Student T-test. From our analysis of the apheresis product, the main cell compartments that were significantly increased in the ES+ group were the % CD8+ T cells [5.41 mean ± 0.51 s.e. vs. 3.34 ± 0.36 (ES-), p=0.003] and naïve CD8+ T cells [3.76 ± 0.56 vs. 1.61 ± 0.18 (ES-), p In the monocyte compartment, the main subset that was significantly increased was the non-classical CD16+CD14low cells in the ES+ group [0.40 ± 0.08 vs. 0.25 ± 0.03 (ES-), p=0.02]. In addition, the % of CD25+ and CD163+ non-classical and intermediate monocytes were favorably increased in the ES+ group (non-classical monocytes, CD25+ [0.14 ± 0.03 vs. 0.07 ± 0.02 (ES-), p=0.03] and CD163+ [0.33 ± 0.06 vs. 0.18 ± 0.02 (ES-), p=0.03]; and for intermediate monocytes, CD25+ [0.44 ± 0.1 vs. 0.22 ± 0.04 (ES-), p=0.02] and CD163+ (p=0.02). No major differences were observed between ES+ and ES- groups for CD64 and PDL-1 expression. CONCLUSIONS: The development of ES correlated with the observation of a significant increase of naïve and activated CD8 T cells in the autologous apheresis product. In contrast, no significant differences were found between the ES+ and ES- groups in the CD4 T cell or memory Treg subsets, suggesting that they do not contribute to the etiology of the syndrome. Moreover, an increased presence of non-classical monocytes with higher expression of both CD163 and CD25 was found, suggesting increased potential for both M2 and M1 activity. Further investigation is needed to determine the implications of these findings for the development of ES. Disclosures Siegel: Merck: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Karyopharm: Consultancy, Honoraria; Novartis: Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Takeda: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau. Biran:BMS: Research Funding; Merck: Research Funding; Amgen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau. Feldman:Johnson and Johnson: Speakers Bureau; KITE: Speakers Bureau; Seattle Genetics: Research Funding, Speakers Bureau; Pharmacyclics: Speakers Bureau; Janssen: Speakers Bureau; Portola: Research Funding; Celgene: Speakers Bureau. Skarbnik:Gilead Sciences: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau.

Background: Autologous stem cell transplantation (ASCT) remains a standard of care for patients with high-risk and recurrent diffuse large B cell lymphoma (DCLBL), T cell lymphoma (TCL) and multiple myeloma (MM). The discovery that differences in the composition of the gut microbiome contribute to the heterogeneity of response to chemotherapies or immunotherapies has prompted us to investigate the influence of the gut microbiome on progression-free survival (PFS) and overall survival in these patient populations treated with combined nivolumab (Nivo) and ipilimumab (Ipi) in the post-ASCT consolidation setting. Methods: Longitudinal analysis of the gut microbiome was performed on stool samples collected from 26 patients (6 de novo DLBCL, 5 recurrent DLBCL, 1 de novo high-risk T cell lymphoma 2 recurrent TCL, 7 transplant-naïve high-risk MM, 4 recurrent MM) treated with Nivo + Ipi, 14-28 days post-ASCT. Stool samples were collected from patients prior to conditioning and ASCT (baseline) and at engraftment (within 72 hrs of absolute neutrophil count ≥ 500/mcL). Stool samples were then collected serially on Weeks 1, 4, 7, 12, 18 and 26 of treatment, 9, 12 and 18 months post-ASCT and at relapse of disease. The composition of the gut microbiome was identified using 16S rRNA sequencing of the V4 amplicon and bioinformatic analysis of α- and β-diversity metrics was performed using the Second Genome Microbiome Discovery Platform. Patients were classified as early relapsers, (n=5), PFS Results: An average of 267 operational taxonomic units (OTUs) was identified per patient sample with a Shannon diversity index of 2.85. The top phyla in DLBCL, TCL and MM included Firmicutes, Bacteroides, Actinobacteria, Proteobacteria, Verrucomicrobia and Euryarchaeota and most samples were dominated by Firmicutes. The top families included Lachnospiraceae, Ruminococcaceae, Bacteroidaceae, Enterococcaceae, Erysipelotrichaceae, Bifidobacteriaceae, Enterobacteriaceae and Streptococcaceae. The Shannon diversity index was reduced at engraftment (2.26) compared to at time of conditioning (3.15) and full recovery of diversity was attained at week 18 of treatment (3.15). At conditioning, Firmicutes, followed by Actinobacteria, and Bacteroides dominated the microbiomes in all indications and at the family level, Lachnospiraceae followed by Ruminococcaceae were major components of the microbiome. The microbiome, at the phylum and family levels, also varied considerably between conditioning and at relapse. While significant shifts in microbiome β-diversity appeared to be associated with indication and timepoint (PERMANOVA, P A significant change of the relative abundance of the Bacteroidetes phylum at conditioning, engraftment, prior to consolidation and on-treatment (Week 7) was observed in the Short-PFS group (Friedman Test, 0.0638, P Conclusions: Our interim taxonomic analyses of 26 patients suggest that the taxonomic identity of the microbiomes were largely similar across indications and timepoints, but the relative abundances of the phylotypes differed between samples. While our results suggest that Bacteroidetes and Verrucomicrobia at conditioning and engraftment may correlate with the likelihood of Short-PFS versus Long-PFS, our results need to be validated in ongoing cohort expansion studies. Disclosures Biran: Celgene: Consultancy, Honoraria, Speakers Bureau; Merck: Research Funding; Takeda: Consultancy, Speakers Bureau; BMS: Research Funding; Amgen: Consultancy, Speakers Bureau. Siegel:Takeda: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Merck: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau. Vesole:Amgen: Speakers Bureau; Takeda: Speakers Bureau. Munshi:Kite: Speakers Bureau. Atkins:BMS: Consultancy; Merck: Consultancy. Feldman:Johnson and Johnson: Speakers Bureau; Portola: Research Funding; Celgene: Speakers Bureau; KITE: Speakers Bureau; Janssen: Speakers Bureau; Seattle Genetics: Research Funding, Speakers Bureau; Pharmacyclics: Speakers Bureau. Skarbnik:Genentech: Honoraria, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Interactions of toll-like receptors (TLRs) with nonmicrobial factors play a major role in the pathogenesis of early trauma-hemorrhagic shock (T/HS)-induced organ injury and inflammation. Thus, we tested the hypothesis that TLR4 mutant (TLR4 mut) mice would be more resistant to T/HS-induced gut injury and polymorphonuclear neutrophil (PMN) priming than their wild-type littermates and found that both were significantly reduced in the TLR4 mut mice. In addition, the in vivo and ex vivo PMN priming effect of T/HS intestinal lymph observed in the wild-type mice was abrogated in TLR4 mut mice as well the TRIF mut-deficient mice and partially attenuated in Myd88 mice, suggesting that TRIF activation played a more predominant role than MyD88 in T/HS lymph-induced PMN priming. Polymorphonuclear neutrophil depletion studies showed that T/HS lymph-induced acute lung injury was PMN dependent, because lung injury was totally abrogated in PMN-depleted animals. Because the lymph samples were sterile and devoid of endotoxin or bacterial DNA, we investigated whether the effects of T/HS lymph was related to endogenous nonmicrobial TLR4 ligands. High-mobility group box 1 protein 1, heat shock protein 70, heat shock protein 27, and hyaluronic acid all have been implicated in ischemia-reperfusion-induced tissue injury. None of these "danger" proteins appeared to be involved, because their levels were similar between the sham and shock lymph samples. In conclusion, TLR4 activation is important in T/HS-induced gut injury and in T/HS lymph-induced PMN priming and lung injury. However, the T/HS-associated effects of TLR4 on gut barrier dysfunction can be uncoupled from the T/HS lymph-associated effects of TLR4 on PMN priming.

Gut injury and loss of normal intestinal barrier function are key elements in the paradigm of gut-origin systemic inflammatory response syndrome, acute lung injury, and multiple organ dysfunction syndrome (MODS). As hypoxia-inducible factor (HIF-1) is a critical determinant of the physiological and pathophysiological response to hypoxia and ischemia, we asked whether HIF-1 plays a proximal role in the induction of gut injury and subsequent lung injury. Using partially HIF-1α-deficient mice in an isolated superior mesenteric artery occlusion (SMAO) intestinal ischemia reperfusion (I/R) injury model (45 min SMAO followed by 3 h of reperfusion), we showed a direct relationship between HIF-1 activation and intestinal I/R injury. Specifically, partial HIF-1α deficiency attenuated SMAO-induced increases in intestinal permeability, lipid peroxidation, mucosal caspase-3 activity, and IL-1β mRNA levels. Furthermore, partial HIF-1α deficiency prevented the induction of ileal mucosal inducible nitric oxide synthase (iNOS) protein levels after SMAO and iNOS deficiency ameliorated SMAO-induced villus injury. Resistance to SMAO-induced gut injury was also associated with resistance to lung injury, as reflected by decreased levels of myeloperoxidase, IL-6 and IL-10 in the lungs of HIF-1α+/− mice. In contrast, a short duration of SMAO (15 min) followed by 3 h of reperfusion neither induced mucosal HIF-1α protein levels nor caused significant gut and lung injury in wild-type or HIF-1α+/− mice. This study indicates that intestinal HIF-1 activation is a proximal regulator of I/R-induced gut mucosal injury and gut-induced lung injury. However, the duration and severity of the gut I/R insult dictate whether HIF-1 plays a gut-protective or deleterious role.

Acute lung injury (ALI) and the development of the multiple organ dysfunction syndrome (MODS) are major causes of death in trauma patients. Gut inflammation and loss of gut barrier function as a consequence of splanchnic ischemia-reperfusion (I/R) have been implicated as the initial triggering events that contribute to the development of the systemic inflammatory response, ALI, and MODS. Since hypoxia-inducible factor (HIF-1) is a key regulator of the physiological and pathophysiological response to hypoxia, we asked whether HIF-1 plays a proximal role in the induction of gut injury and subsequent lung injury. Utilizing partially HIF-1α-deficient mice in a global trauma hemorrhagic shock (T/HS) model, we found that HIF-1 activation was necessary for the development of gut injury and that the prevention of gut injury was associated with an abrogation of lung injury. Specifically, in vivo studies demonstrated that partial HIF-1α deficiency ameliorated T/HS-induced increases in intestinal permeability, bacterial translocation, and caspase-3 activation. Lastly, partial HIF-1α deficiency reduced TNF-α, IL-1β, cyclooxygenase-2, and inducible nitric oxide synthase levels in the ileal mucosa after T/HS whereas IL-1β mRNA levels were reduced in the lung after T/HS. This study indicates that prolonged intestinal HIF-1 activation is a proximal regulator of I/R-induced gut mucosal injury and gut-induced lung injury. Consequently, these results provide unique information on the initiating events in trauma-hemorrhagic shock-induced ALI and MODS as well as potential therapeutic insights.

Organ failure is a common cause of morbidity and mortality in patients sustaining major trauma, and hence, the pathophysiology of trauma-induced organ injury and dysfunction has been an important line of research.1 Based on these trauma studies, it is clear that shock-induced changes and trauma-induced changes in neutrophil activation are involved in the pathogenesis of the adult respiratory distress syndrome and contribute to the development of the multiple organ dysfunction syndrome.1 Likewise, recent work suggests that impaired red blood cell (RBC) deformability, which occurs in sepsis, after trauma, and during shock states,2–4 contributes to the development of multiple organ dysfunction syndrome by impairing tissue microvascular blood flow.5 Consequently, understanding the factors that modulate the magnitude and extent of neutrophil activation and RBC deformability might provide important insights into ways to limit post-trauma organ dysfunction.1 Because gender and sex hormones have been shown to modulate the development of organ injury as well as the immune system in preclinical models of trauma-hemorrhagic shock (T/HS)6–10 and in some but not all clinical studies,11 we have been interested in investigating the effects of gender and sex hormones on T/HS-induced changes in neutrophil and RBC function. Our earlier studies documented that neutrophil activation12 and RBC rigidification13 were reduced in female as opposed to male rats subjected to T/HS and that estrogen played a protective role in these studies. Because the beneficial effects of estrogen (17β-estradiol) seem to occur through high-affinity estrogen receptors (ER), the major goal of this study was to investigate the relative role that each of the two principal ERs (ER-α and -β) played in protecting against trauma-shock-induced RBC dysfunction, as measured by RBC deformability and neutrophil activation. To accomplish this goal, we administered either the ER-α agonist propyl pyrazole triol (PPT) or the ER-β agonist diarylpropiolnitrile (DPN) to ovariectomized (OVX) rats. These agents were chosen as PPT has a 410-fold higher binding affinity preference for ER-α over ER-β,14 whereas DPN exhibits a 70-fold higher binding affinity to ER-β than ER-α.15

Intestinal ischemia after trauma-hemorrhagic shock (T/HS) results in gut barrier dysfunction and the production/release of biologically active and tissue injurious factors in the mesenteric lymph, which, in turn, causes acute lung injury and a systemic inflammatory state. Since T/HS-induced lung injury is associated with pulmonary endothelial and epithelial cell programmed cell death (PCD) and was abrogated by mesenteric lymph duct ligation, we sought to investigate the cellular pathways involved. Compared with trauma-sham shock (T/SS) rats, a significant increase in caspase-3 and M30 expression was detected in the pulmonary epithelial cells undergoing PCD, whereas apoptosis-inducing factor (AIF), but not caspase-3, was detected in endothelial cells undergoing PCD. This AIF-mediated pulmonary endothelial PCD response was validated in an in situ femoral vein assay where endothelial cells were found to express AIF but not caspase-3. To complement these studies, human umbilical vein endothelial cell (HUVEC), human lung microvascular endothelial cell (HLMEC), and human alveolar type II epithelial cell (A549) lines were used as in vitro models. T/HS lymph induced the nuclear translocation of AIF in HUVEC and HLMEC, and caspase inhibition in these cells did not afford any cytoprotection. For proof of principle, AIF silencing in HUVEC reversed the cytotoxic effects of T/HS on cell viability and DNA fragmentation. In A549 cells, T/HS lymph activated caspase-3-mediated apoptosis, which was partially abrogated by N-benzyloxycarbonyl-Val-Ala-Asp (zVAD). Additionally, T/HS lymph did not cause the nuclear translocation of AIF in A549 cells. Collectively, T/HS-induced pulmonary endothelial PCD occurs via an AIF-dependent caspase-independent pathway, whereas epithelial cells undergo apoptosis by a caspase-dependent pathway.

The goal of this study was to test the hypothesis that factors released from the gut and carried in the mesenteric lymph contribute to mortality in a lethal gut I/R model. To test this hypothesis, a lethal splanchnic artery occlusion (SAO) shock model was used in male Sprague-Dawley rats. In the first set of experiments, ligation of the mesenteric lymph duct (LDL), which prevents gut-derived factors carried in the intestinal lymphatics from reaching the systemic circulation, significantly improved 24-h survival after a 20-min SAO insult (0% vs. 60% survival; P0.05). This increase in survival in the LDL-treated rats was associated with a blunted hypotensive response. Because increased iNOS-induced NO levels have been implicated in SAO-induced shock, we measured plasma nitrite/nitrate levels and liver iNOS protein levels in a second group of animals. Ligation of the mesenteric lymph duct significantly abrogated the SAO-induced increase in plasma nitrite/nitrate levels and the induction of hepatic iNOS (P0.05). In an additional series of studies, we documented that LDL increased not only 24-h but also long-term 7-day survival. During the course of these studies, we made the unexpected finding that Sprague-Dawley rats from different animal vendors had differential resistance to SAO, and that the time of the year that the experiments were carried out also influenced the results. Nonetheless, in conclusion, these studies support the hypothesis that factors carried in the mesenteric lymph significantly contribute to the development of irreversible shock after SAO.

The etiology of trauma-hemorrhagic shock (T/HS)-induced acute lung injury has been difficult to elucidate because of, at least in part, the inability of in vivo studies to separate the noninjurious pulmonary effects of trauma-hemorrhage from the tissue-injurious ones. To circumvent this in vivo limitation, we used a model of T/HS in which T/HS lung injury was abrogated by dividing the mesenteric lymph duct. In this way, it was possible to separate the pulmonary injurious response from the noninjurious systemic response to T/HS by comparing the pulmonary molecular responses of rats subjected to T/HS, which did and did not develop lung injury, with those of nonshocked rats. Using high-density oligonucleotide arrays and treatment group comparisons of whole lung tissue collected at 3 h after the end of the shock or sham-shock period, 139 of 8,799 assessed genes were identified by significant analysis of microarrays. Hemorrhage without the secondary effects of lung injury modulated the expression of 21 genes such as interleukin 1beta, metallothionein-2, and myeloctomatosis oncogene (c-myc). In response to injury, 42 genes were identified to be differentially expressed. Upregulated genes included the L1 retroposon and guanine deaminase, whereas downregulated genes included catalase and superoxide dismutase 1. Real-time polymerase chain reaction confirmed the differential expression for selected genes. PathwayAssist analysis identified interleukin 1beta as a central regulator of two subpathways of stress response-related genes (c-myc and superoxide dismutase 1/catalase) as well as several unrelated genes such as lipoprotein lipase. Our model system provided a unique opportunity to distinguish the molecular changes associated with T/HS-induced acute lung injury from the systemic molecular response to T/HS.

In both animal models of hemorrhagic shock and clinical settings, shock-induced gut ischemia has been implicated in the development of the systemic inflammatory response syndrome and distant organ injury, yet the factors transducing these events remain to be fully determined. Because hypoxia-inducible factor (HIF-1), a transcription factor composed of oxygen-labile HIF-1alpha and constitutive HIF-1beta subunits, regulates the physiologic/pathophysiologic response to hypoxia and ischemia, we examined the HIF-1 response in two rat models of gut ischemia-reperfusion. We found that ileal nuclear HIF-1alpha protein levels were induced in rats subjected to trauma (laparotomy) plus hemorrhagic shock for 90 min relative to their trauma sham-shock and naïve counterparts and that this trauma hemorrhagic shock-induced mucosal HIF-1alpha protein response persisted after 1 h and 3 h of reperfusion. Likewise, in a model of isolated gut ischemia-reperfusion injury, where the superior mesenteric artery was occluded for 45 min, nuclear HIF-1alpha were induced in the gut mucosa relative to their sham counterparts and persisted after 1 h and 3 h or reperfusion. Similar to the in vivo response, in vitro hypoxia induced HIF-alpha expression in three different enterocyte cell lines (rat IEC-6 and human Caco-2 and HT-29 cell lines). However, in contrast to the in vivo response, HIF-1 expression rapidly disappeared on subsequent reoxygenation. Because in vivo enterocytes are exposed to bacteria, we tested whether the in vitro HIF-1alpha response would persist on reoxygenation if the enterocytes were cocultured with bacteria. P. aeruginosa, an enteric bacterium, markedly induced enterocyte HIF-1alpha protein levels under normoxic conditions. Furthermore, the addition of P. aeruginosa during either the hypoxic or reoxygenation phase prevented the degradation of HIF-1alpha protein levels. Moreover, the observation that lipopolysaccharide induced HIF-1alpha expression in a time-dependent manner in IEC-6 cells indicated that the induction of HIF-1 by exposure to P. aeruginosa is not dependent on bacterial viability. In conclusion, these results suggest that HIF-1alpha activation is an early reperfusion-independent event in models of gut ischemia-reperfusion and that this HIF-1alpha response is potentiated by the presence of P. aeruginosa or lipopolysaccharide.

Purpose: Cytotoxic chemotherapy has been used to treat patients with metastatic colorectal cancer with limited success. Therefore novel chemotherapeutic approaches are needed. Based on encouraging preclinical data, there has been an interest in developing derivatives of butyrate as clinically applicable agents. The purpose of this study was to investigate the effects of phenylbutyrate (PB), a butyrate analogue, on the cell growth and apoptosis in a colon cancer cell model. Methods: Growth curves, flow cytometric studies, Western blotting, DNA binding assays and transient transfection experiments were performed in vitro using the colon cancer cell line HT-29 after exposure to PB. Results: Exposure of HT-29 colon cancer cells to PB resulted in growth inhibition and induction of apoptosis as measured by annexin V staining. This increase in apoptosis was associated with a decrease in mitochondrial membrane potential, an increase in caspase-3 activity and a decrease in intact PARP protein levels. Since NF-κB plays a pivotal role in the regulation of apoptosis, we explored the effects of PB on the DNA binding and transcriptional activity of this transcription factor. After PB treatment, NF-κB-DNA binding was markedly decreased and specifically, this decreased DNA binding was observed in the p50:p65 heterodimer. The decreased NF-κB DNA binding was observed as early as 3 h after PB treatment, while no apparent changes in annexin V binding were detected until 12 h after PB treatment. Untreated HT-29 cells transfected with a κB-luciferase reporter plasmid demonstrated significant constitutive activity of the κB binding site, which was markedly decreased after treating the cells with PB. Conclusion: These results suggest that PB-induced apoptosis may be partly regulated through the inactivation of NF-κB. PB, an oral butyrate analogue, may have therapeutic potential in colon cancer.

The etiology of graft-versus-host disease (GVHD) is rooted in the alloreactive response of donor T cells present in the hematopoietic graft resulting in the destruction of the patient's tissues, particularly the gastrointestinal tract. Gut GVHD affects up to 50% of patients, is a leading cause of death, and has overlapping features with inflammatory bowel disease (IBD). Increased gut permeability, alterations of the gut microbiome and intestinal stem cell niche damage predispose the gut to the local and systemic effects of GVHD, and is exacerbated by the inability of the gut to adequately regenerate. Severe shifts in metabolism and reduced oxygen (O2) availability in the inflamed gut are major underlying factors in the pathogenesis of IBD. Two related transcription factors, hypoxia-inducible factor-1 (HIF-1) and HIF-2, originally discovered as master regulators of the adaptive response to hypoxia, have been recently shown to be gut protective and promote mucosal healing in response to injury. Using a MHC mismatched B10.BR→B6 bone marrow transplant (BMT) model, we previously found that loss of intestinal epithelial (IE) HIF-1α or HIF-2α worsened survival compared to wild-type mice and exhibited increased GVHD-induced-histopathology. Thus, we hypothesized that HIF-1 and HIF-2 protects and repairs the gut from conditioning and GVHD-related damage. HIF-1 and HIF-2 are heterodimers consisting of an O2-labile HIF-1α or HIF-2α subunit respectively and a constitutively expressed HIF-1β subunit. The recent discovery that iron-dependent prolyl hydroxylase enzymes (PHD1-3) can trigger the O2-dependent proteasomal degradation of the HIF-1α subunit has led to the development of pan-PHD inhibitors (PHDi) that activate HIF-1 and HIF-2. PHDi such as dimethyloxallyl glycine (DMOG) and AKB-4924 have been shown to attenuate colitis and radiation-induced gut toxicity in animal models. We thus sought to determine whether PHDi could also ameliorate gut GVHD in the B10.BR→B6 BMT model. B6 mice were lethally irradiated (10Gy, split dose) and transplanted with 5x106 T-cell depleted bone marrow (BM) cells from B10.BR donors with 2x106 enriched T cells from spleens and lymph nodes (BM+T). B6 mice transplanted with only T cell depleted BM cells served as our non-GVHD control group. B6 mice were treated with AKB-4924 (AKB, 5 mg/kg) or vehicle (β-cyclodextrin) via intraperitoneal delivery, beginning 1 day prior to BMT and for 6 consecutive days post-BMT. Treatment with AKB prevented significant weight loss, compared to vehicle-treated mice, 7 days post-BMT (n=6, p Disclosures Peters: Aerpio Therapeutics: Employment, Equity Ownership.

The molecular mechanisms by which multiple myeloma (MM) cells evade glucocorticoid-induced apoptosis have not been delineated. Using a human IgAκ MM cell line (ARP-1), we found that dexamethasone (Dex)-induced apoptosis is associated with decreased NF-κB DNA binding and κB-dependent transcription. Both nuclear p50:p50 and p50:p65 NF-κB complexes are detected in ARP-1 cells by supershift electrophoretic mobility shift assay (EMSA). Dex-mediated inhibition of NF-κB DNA binding precedes a notable increase in annexin V binding, thereby indicating that diminished NF-κB activity is an early event in Dex-induced apoptosis. Overexpression of bcl-2 in ARP-1 cells prevents Dex-mediated repression of NF-κB activity and apoptosis. Sustained NF-κB DNA binding is also observed in two previously characterized Dex-resistant MM cell lines (RPMI8226 and ARH-77) that express moderate levels of endogenous bcl-2 and IκB proteins. In addition, enforced bcl-2 expression in ARP-1 cells did not prevent the augmentation of IκB protein by Dex. We also noted a possible association between Dex-mediated downregulation of NF-κB in freshly obtained primary myeloma cells and the patients’ responsiveness to glucocorticoid-based chemotherapy. Collectively, our data suggest that the protective effects of bcl-2 in MM cells act upstream in the NF-κB activation–signaling pathway and the potential use of NF-κB as a biomarker in progressive MM.

A tripartite domain of the immunoglobulin mu heavy-chain gene enhancer that activates transcription in B cells contains binding sites for PU.1, Ets-1, and a leucine zipper-containing basic helix-loop-helix factor. Because PU.1 is expressed only in B cells and macrophages, we tested the activity of a minimal mu enhancer fragment in macrophages by transient transfections. The minimal mu enhancer activated transcription in macrophages, and the activity was dependent on all three sites. Analysis of mutated enhancers, in which spacing and orientation of the ETS protein binding sites had been changed, suggested that the mechanisms of enhancer activation were different in B cells and macrophages. Thus, ETS protein binding sites may be combined in different ways to generate tissue-specific transcription activators. Despite the activity of the minimal enhancer in macrophages, a larger mu enhancer fragment was inactive in these cells. We propose that formation of the nucleoprotein complex that is formed on the minimal enhancer in macrophages cannot be helped by the neighboring muE elements that are essential for activity of the monomeric enhancer.

The failure to control both innate and adaptive immune responses in the gut has recently been implicated as a major pathogenic mechanism in the development of graft-versus-host disease (GVHD). Reduced oxygen availability in the intestine has been causally linked to gastrointestinal disease. During intestinal inflammation, increased metabolic activity of resident and infiltrating immune cells, bacteria and reduced blood flow may lead to a sharp decrease of oxygen, resulting in "inflammatory" hypoxia. The transcription factor family, hypoxia-inducible factor (HIF) originally discovered as a master regulator of the adaptive response to hypoxia, has recently emerged as a key regulator of the innate and adaptive immune responses. The HIF heterodimer consists of an oxygen-labile α subunit (HIFα) and a constitutively expressed HIF-1β subunit. Both HIF-1α and HIF-2α expression are markedly elevated in intestinal epithelial cells of patients with inflammatory bowel disease (IBD) and intestinal epithelial HIF-1 attenuates colitis in preclinical mouse models. Although HIF-2 has not been studied extensively in intestinal inflammation, it has emerged as a key regulator in intestinal iron homeostasis. Given that IBD and GVHD share many pathogenic mechanisms, we hypothesized that a sustained HIF response will protect the host intestinal epithelium from conditioning- and alloreactive T cell-induced gut damage. To determine the functional significance of intestinal epithelial HIF-1 and HIF-2 in gut GVHD, we generated conditional intestinal epithelial HIF-1α (HIF-1αΔIE) and HIF-2αΔIE vil-cre knockout (KO) mice on a C57BL/6 (B6) background lacking HIF-1α or HIF-2α in the host intestinal epithelium. Using a fully MHC mismatched B10.BR (H2k)→B6 (H2b) bone marrow transplant (BMT) model, loss of intestinal epithelial HIF-2 reduced the median survival time (43d) compared to wild-type (WT) recipients (58d, log-rank test, P < 0.005). Although intestinal epithelial HIF-1 deficiency shortened the median survival time (48.5d), it did not reach statistical difference. Loss of intestinal epithelial HIF-1 or HIF-2 worsened GVHD-induced histopathologic crypt damage compared to WT mice transplanted with T cell depleted bone marrow (BM) and enriched T cells (BM+T), 8d post- BMT. Pronounced subepithelial lifting, mucosal edema and sloughing were more evident in the villus tips of HIF-2αΔIE mice than HIF-1αΔIE mice. Hyperplastic crypts that are characteristic of regenerating crypts after radiation-induced damage were observed in Ki67-stained ileal/jejunal sections of WT mice post-BMT whereas fewer regenerating Ki67-labeled crypts were found in both HIF-1αΔIE and HIF-2αΔIE mice. In control T cell depleted BM groups (WT, HIF-1αΔIE and HIF-2αΔIE), Ki67+ -proliferating cells resided at the crypt base. Using quantitative real-time PCR analysis, we determined whether intestinal epithelial HIF-1 and HIF-2 differentially regulated the expression of Paneth cells and intestinal stem cell markers in the jejunum, 8d post-BMT. A 5-fold and 2-fold decrease in lysozyme (Lyz) mRNA levels occurred in WT (p Disclosures No relevant conflicts of interest to declare.

Expression of the low-affinity Fc receptor for IgG (murine Fc gamma RIIIA) is restricted to cells of myelomonocytic origin. We report here the promoter structure, the proximal DNA sequences responsible for transcription of Fc gamma RIIIA in macrophages and the protein factors which interact with these sequences. A 51 bp sequence, termed the myeloid restricted region (MRR), was both necessary and sufficient for conferring cell type-specific expression in macrophages. Reporter constructs containing mutations in this sequence result in the loss of MRR activity upon transfection into the macrophage cell line, RAW264.7. Two cis-acting elements have been identified and are required for full promoter function. These same elements analyzed by EMSA define two binding sites recognized by nuclear factors derived from macrophages. A 3' purine tract (-50 to -39) within the MRR binds the macrophage and B cell-specific factor, PU.1, and a second E box-like element, termed MyE, upstream of the PU.1 box (-88 to -78) binds the HLH factors TFE3 and USF. EMSA studies using RAW cell extracts suggest that both PU.1 and MyE factors may bind simultaneously to the MRR resulting in a ternary complex that is responsible, in part, for the myeloid-specific activity of the Fc gamma RIIIA promoter.

Many models of trauma-hemorrhagic shock (T/HS) involve the reinfusion of anticoagulated shed blood. Our recent observation that the anticoagulant heparin induces increased mesenteric lymph lipase activity and consequent in vitro endothelial cell cytotoxicity prompted us to investigate the effect of heparin-induced lipase activity on organ injury in vivo as well as the effects of other anticoagulants on mesenteric lymph bioactivity in vitro and in vivo. To investigate this issue, rats subjected to trauma-hemorrhage had their shed blood anticoagulated with heparin, the synthetic anticoagulant arixtra (fondaparinux sodium), or citrate. Arixtra, in contrast to heparin, did not increase lymph lipase activity or result in high levels of endothelial cytotoxicity. Yet, the arixtra-treated rats subjected to T/HS still manifested lung injury, neutrophil priming, and red blood cell dysfunction, which was totally abrogated by lymph duct ligation. Furthermore, the injection of T/HS mesenteric lymph, but not sham-shock lymph, collected from the arixtra rats into control mice recreated the pattern of lung injury, polymorphonucleocyte (PMN) priming, and red blood cell dysfunction observed after actual shock. Consistent with these observations, citrate-anticoagulated rats subjected to T/HS developed lung injury, and the injection of mesenteric lymph from the citrate-anticoagulated T/HS rats into control mice also resulted in lung injury. Based on these results, several conclusions can be drawn. First, heparin-induced increased mesenteric lymph lipase activity is not responsible for the in vivo effects of T/HS mesenteric lymph. Second, heparin should be avoided as an anticoagulant when studying the biology or composition of mesenteric lymph because of its ability to cause increases in lymph lipase activity that increase the in vitro cytotoxicity of these lymph samples.

BackgroundInjurious non-microbial factors released from the stressed gut during shocked states contribute to the development of acute lung injury (ALI) and multiple organ dysfunction syndrome (MODS). Since Toll-like receptors (TLR) act as sensors of tissue injury as well as microbial invasion and TLR4 signaling occurs in both sepsis and noninfectious models of ischemia/reperfusion (I/R) injury, we hypothesized that factors in the intestinal mesenteric lymph after trauma hemorrhagic shock (T/HS) mediate gut-induced lung injury via TLR4 activation.Methods/principal findingsThe concept that factors in T/HS lymph exiting the gut recreates ALI is evidenced by our findings that the infusion of porcine lymph, collected from animals subjected to global T/HS injury, into naïve wildtype (WT) mice induced lung injury. Using C3H/HeJ mice that harbor a TLR4 mutation, we found that TLR4 activation was necessary for the development of T/HS porcine lymph-induced lung injury as determined by Evan's blue dye (EBD) lung permeability and myeloperoxidase (MPO) levels as well as the induction of the injurious pulmonary iNOS response. TRIF and Myd88 deficiency fully and partially attenuated T/HS lymph-induced increases in lung permeability respectively. Additional studies in TLR2 deficient mice showed that TLR2 activation was not involved in the pathology of T/HS lymph-induced lung injury. Lastly, the lymph samples were devoid of bacteria, endotoxin and bacterial DNA and passage of lymph through an endotoxin removal column did not abrogate the ability of T/HS lymph to cause lung injury in naïve mice.Conclusions/significanceOur findings suggest that non-microbial factors in the intestinal mesenteric lymph after T/HS are capable of recreating T/HS-induced lung injury via TLR4 activation.

Background Acute lung injury (ALI) and the development of the multiple organ dysfunction syndrome (MODS) is a major cause of death in trauma patients. Earlier studies in trauma hemorrhagic shock (T/HS) have documented that splanchnic ischemia leading to gut inflammation and loss of barrier function is an initial triggering event that leads to gut-induced ARDS and MODS. Since sex hormones have been shown to modulate the response to T/HS and proestrous (PE) females are more resistant to T/HS-induced gut and distant organ injury, the goal of our study was to determine the contribution of estrogen receptor (ER)alpha and ERbeta in modulating the protective response of female rats to T/HS-induced gut and lung injury. Methods/principal findings The incidence of gut and lung injury was assessed in PE and ovariectomized (OVX) female rats subjected to T/HS or trauma sham shock (T/SS) as well as OVX rats that were administered estradiol (E2) or agonists for ERalpha or ERbeta immediately prior to resuscitation. Marked gut and lung injury was observed in OVX rats subjected to T/HS as compared to PE rats or E2-treated OVX rats subjected to T/HS. Both ERalpha and ERbeta agonists were equally effective in limiting T/HS-induced morphologic villous injury and bacterial translocation, whereas the ERbeta agonist was more effective than the ERalpha agonist in limiting T/HS-induced lung injury as determined by histology, Evan's blue lung permeability, bronchoalevolar fluid/plasma protein ratio and myeloperoxidase levels. Similarly, treatment with either E2 or the ERbeta agonist attenuated the induction of the intestinal iNOS response in OVX rats subjected to T/HS whereas the ERalpha agonist was only partially protective. Conclusions/significance Our study demonstrates that estrogen attenuates T/HS-induced gut and lung injury and that its protective effects are mediated by the activation of ERalpha, ERbeta or both receptors.

Objective: To test the hypothesis that gut-derived factors carried in trauma-hemorrhagic shock (T/HS) lymph is sufficient to induce lung injury. Additionally, because our previous studies showed that T/HS-induced nitric oxide production was associated with lung injury, we examined whether T/HS lymph-induced lung injury occurs via an inducible nitric oxide synthase (iNOS)-dependent pathway. Background: We have previously shown that T/HS-induced lung injury is mediated by gut-derived humoral factors carried in the mesenteric lymph. However, it remains unclear whether T/HS lymph itself is sufficient to induce lung injury, or requires the activation of other factors during the T/HS period to exert its effect. Methods: Mesenteric lymph collected from T/HS or trauma-sham shock (T/SS) animals was injected intravenously into male rats at a rate of 1 mL/h for 3 hours. At the end of infusion, lung injury was assessed by lung permeability and lung histology. The effect of iNOS inhibition on T/HS lymph-induced lung injury was studied and this was further confirmed in iNOS knockout mice. Finally, iNOS immunohistochemistry was performed to identify the cells of origin of iNOS. Results: The injection of T/HS lymph, but not sham shock lymph, caused lung injury. This was associated with increased plasma nitrite/nitrate levels as well as induction of iNOS protein in the lung, liver, and gut. Treatment with the selective iNOS inhibitor aminoguanidine prevented T/HS lymph-induced lung injury. iNOS knockout mice, but not their wild-type controls, were resistant to T/HS lymph-induced lung injury. By immunohistochemistry, neutrophils and macrophages, rather than parenchymal cells, were the source of T/HS lymph-induced lung iNOS. Conclusions: These results indicate that T/HS lymph is sufficient to induce acute lung injury and that lymph-induced lung injury occurs via an iNOS-dependent pathway.

Acute graft-versus-host disease (GVHD) is a major cause of nonrelapse morbidity and mortality following allogeneic blood and marrow transplantation (BMT). The majority of studies delineating the mechanisms involved in GVHD have focused on the alloreactive T cell response and their downstream cellular and inflammatory effector phases. While these efforts have provided important mechanistic insights that have been translated into therapies that target the T cell compartment, they ignore the role that the target organ plays in both initiating and propagating this disease. Acute gut GVHD affects more than 60% of patients and is a leading cause of death. The mechanisms for the early, conditioning-related, intestinal injuries that are the precipitating event leading to GVHD or how subsequent gut-specific GVHD actually disrupts intestinal homeostasis have not been fully explored. The transcription factor, hypoxia inducible factor-1 (HIF-1) has emerged as a common denominator for hypoxia and inflammation. Given that inflammatory bowel disease (IBD) and GVHD share many pathogenic mechanisms and intestinal epithelial HIF-1α afforded protection in IBD models, we hypothesize that the persistent activation of HIF-1 will protect the intestinal epithelium from radiation/chemotherapy and alloreactive T cell-induced damage. Since crypt damage is a hallmark of gut GVHD, we first determined whether loss of intestinal epithelial HIF-1α impaired intestinal regeneration after GVHD damage using conditional HIF-1α (HIF-1αIE) knockout mice that lack HIF-1α in the intestinal epithelium. In a major MHC mismatched B10.BR (H2k) into B6 (H2b) GVHD model, 8 days post-BMT, histopathologic assessment of H&E stained ileums of HIF-1αIE mice showed more severe crypt damage, loss of Paneth cells and fewer regenerating crypts as compared to wild-type (WT) mice. A two-fold increase of aberrant mitoses (p Disclosures No relevant conflicts of interest to declare.

The nuclear factor kappa B (NF-kappaB) family of transcription factors plays a major role in inflammation, immune and stress responses, oncogenesis, cell migration, and angiogenesis. Aberrant activation of NF-kappaB has also been shown to contribute to intrinsic and inducible drug resistance in numerous cancers, including multiple myeloma. The expression of NF-kappaB-responsive targets will vary depending on the cellular context and type of inducer. The regulation of NF-kappaB activity occurs at multiple levels involving the IkappaB kinase (IKK) complex, members of the IkappaB family, recruitment of heterologous transcription factors and coactivators by NF-kappaB, and post-translational modifications of p65. This article highlights regulatory mechanisms responsible for constitutive NF-kappaB activation and provides justification for target-based therapy for NF-kappaB in multiple myeloma.

Having documented that proestrus female rats are more resistant to shock-induced acute gut and hence lung injury than male rats, we tested the hypothesis that the female gut is more resistant to injury and produces less of an inflammatory response than the male gut when exposed to conditions associated with shock states (hypoxia and acidosis) utilizing the ex vivo Ussing chamber system. Ileal mucosal membranes harvested from normal male and female rats mounted in Ussing chamber systems were exposed to normoxia or 40 min of hypoxia at a normal pH (pH 7.3) or acidosis (pH 6.8). Cytokine and nitric oxide levels in the serosal compartment of the Ussing chamber were measured at the end of the 3-h experimental period to assess the immunoinflammatory response, whereas FITC-dextran (mol wt 4,300) was employed to assess barrier function. Histomorphological changes were used to quantitate gut mucosal injury. Hypoxia, acidosis, or hypoxia plus acidosis was associated with a significant increase in proinflammatory cytokine production [interleukin (IL)-6, tumor necrosis factor, and macrophage inflammatory protein (MIP)-2] by the male compared with the female intestinal segments. In contrast, the female gut manifested a higher anti-inflammatory response (nitric oxide and IL-10) and improved intestinal barrier function as well as less evidence of mucosal injury than the male intestinal segments. Administration of estradiol or the testosterone receptor antagonist, flutamide, to male rats abrogated the increase in gut injury and the increased IL-6 and MIP-2 response observed after hypoxia plus acidosis. These results suggest that gender differences in the ex vivo intestinal response to stresses, such as hypoxia and acidosis, exist and that the administration of estradiol or blockade of the testosterone receptor to male rats mitigates these gender differences.

The purpose of this study was to investigate the anti-proliferative and pro-apoptotic effects of the butyrate analogues, tributyrin (TB) and phenylbutyrate (PB), in a colon cancer model. We demonstrate that HT-29 colon cancer cells exposed to PB and TB result in growth inhibition associated with an induction of apoptosis mediated through the activation of caspase-3 activity. A block in the G1/S cell cycle traverse associated with a decrease in CDK2 (cyclin dependent kinase) protein levels and retinoblastoma protein hypophosphorylation was also noted after PB and TB exposure. Importantly, TB proved to be the most potent agent in its ability to induce these phenotypic changes, and potentially may represent a novel therapy for patients with advanced colorectal cancer.

The intestinal epithelium is a primary target of graft-versus-host disease (GVHD). The hypoxia-signaling pathway has been implicated as an adaptive response in the intestinal epithelium in numerous models of inflammatory bowel disease, such as colitis and T-cell induced diarrhea. The transcription factor family, hypoxia-inducible factor (HIF) has emerged as master regulators of the transcriptional response to hypoxic stress in normal and transformed cells. HIF heterodimers consist of an oxygen-labile α subunit (HIF-1α, HIF-2α) and a constitutively expressed HIF-1β subunit that mediate a wide spectrum of physiological and cellular adaptive responses, including angiogenesis, metabolic adaption, and erythropoiesis. HIF-1 has recently been implicated as a gut-protective factor in inflammatory bowel disease models by maintaining intestinal homeostasis. HIF-1 can also skew the differentiation of T cells to regulatory T cells (Treg) via the induction of FoxP3, thereby attenuating T-cell driven colitis. Although HIF-1 and HIF-2 share many overlapping functions, HIF-1 has been implicated in the inflammatory phenotype of M1 macrophages via inducible nitric oxide synthase (iNOS) whereas HIF-2 is involved in the anti-inflammatory phenotype of M2 macrophages via arginase-1 (Arg1). Based on these findings and that mucosal inflamed tissues are hypoxic, we hypothesized that the induction of the hypoxia-signaling pathway may limit GVHD-induced mucosal inflammation and injury. To determine the adaptive roles of HIF-1 and HIF-2 in GVHD, we first tested the major histocompatibility complex (MHC)-haploidentical C567BL/6 (B6,H2b) -> B6xDBA/2 (B6D2)F1 (H2b/d) model in which donor spenocytes (2x107) and anti-Thy1 + C’ treated (T- cell depleted) bone marrow (ATBM) cells (5x106) are transplanted into B6D2F1 recipients after exposure to lethal irradiation (11Gy, split dose). B6 ATBM cells transplanted alone into B6D2F1 mice served as a negative control for all comparisons. Realtime PCR analysis demonstrated a modest increase in ileal mucosal HIF-2α expression 8 days (d) post-transplant (pBALB.B and B6->CXB-2 models. However, after 20d post-transplant, a 4- and 3-fold decrease in Arg1 mRNA levels occurred in both models. Likewise, two anti-inflammatory, Treg-associated cytokines, interleukin-10 (IL-10) and transforming growth factor beta (TGFβ) mRNA expression were elevated by 2-and 7-fold, respectively, after d8 in B6->BALB.B mice. TGFβ levels returned to baseline (p0.001) in a B6 anti-B6D2F1 mixed lymphocyte reaction. Taken together, our data suggest that HIF-2/Arg1 axis confers an anti-inflammatory response in the ileum after 8d of GVHD. However, after 20d, this response is inversely correlated with the lethality of the GVHD response. The amelioration of alloreactivity by DMOG suggests that the persistent activation of HIF may be necessary to dampen GVHD. Further studies will delineate the contribution of the HIF-2 response in the maintenance of intestinal homeostasis and limiting T cell alloreactivity. Disclosures: Zilberberg: Onyx Pharmaceuticals: Research Funding. Dziopa:Onyx Pharmaceuticals: Research Funding.

Specific cytogenetic abnormalities have been identified in multiple myeloma that confer a poor prognosis, even with intensive chemotherapy and autotransplants. The identification and characterization of potential genes involved in these different chromosomal changes and their interplay with oncogenes and tumor suppressor genes controlling cellular growth and apoptosis is the major focus of this review.

Cell homeostasis is controlled by a balance between proliferation, growth arrest and apoptosis. It is becoming increasingly evident that dysregulation of genes that control apoptosis contributes to the pathogenesis of disease such as cancer and autoimmune disease (1). In multiple myeloma, myeloma cells are terminally differentiated and fail to apoptose. Glucocorticoids such as dexamethasone (Dex) are often used in the treatment of myeloma, either alone or in combination with cytotoxic agents (2, 3). Similarly, IL-6 in the bone marrow environment protects immature myeloma cells form Dex-induced apoptosis (4). However, with prolonged treatment, patients develop resistance to these agents. It is well established that both glucocorticoids and chemotherapeutic drugs are potent inducers of cell death, by apoptosis (1). In fact, recent studies have demonstrated that Dex-induced apoptosis in several human myeloma cell lines and that interleukin-6 (IL-6), a B cell differentiation/survival factor, protected them from Dex-induced apoptosis (5, 6, Epstein J personal communication). The molecular mechanisms that govern these processes are not fully understood. Restoration of the apoptopic response in myeloma cells could lead to the development of effective therapy for multiple myeloma.