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Purpose: Immune dysfunction reported in renal cell carcinoma (RCC) patients may contribute to tumor progression. Myeloid-derived suppressor cells (MDSC) represent one mechanism by which tumors induce T-cell suppression. Several factors pivotal to the accumulation of MDSC are targeted by the tyrosine kinase inhibitor, sunitinib. The effect of sunitinib on MDSC-mediated immunosuppression in RCC patients has been investigated.Experimental Design: Patient peripheral blood levels of MDSC and regulatory T-cell (Treg) and T-cell production of IFN-γ were evaluated before and after sunitinib treatment. Correlations between MDSC and Treg normalization as well as T-cell production of IFN-γ were examined. The in vitro effect of sunitinib on patient MDSC was evaluated.Results: Metastatic RCC patients had elevated levels of CD33+HLA-DR− and CD15+CD14− MDSC, and these were partially overlapping populations. Treatment with sunitinib resulted in significant reduction in MDSC measured by several criteria. Sunitinib-mediated reduction in MDSC was correlated with reversal of type 1 T-cell suppression, an effect that could be reproduced by the depletion of MDSC in vitro. MDSC reduction in response to sunitinib correlated with a reversal of CD3+CD4+CD25hiFoxp3+ Treg cell elevation. No correlation existed between a change in tumor burden and a change in MDSC, Treg, or T-cell production of IFN-γ. In vitro addition of sunitinib reduced MDSC viability and suppressive effect when used at ≥1.0 μg/mL. Sunitinib did not induce MDSC maturation in vitro.Conclusions: Sunitinib-based therapy has the potential to modulate antitumor immunity by reversing MDSC-mediated tumor-induced immunosuppression.

Supplementary Tables S1-S2 from Sunitinib Mediates Reversal of Myeloid-Derived Suppressor Cell Accumulation in Renal Cell Carcinoma Patients

Myeloid suppressor cells with high arginase activity are found in tumors and spleen of mice with colon and lung cancer. These cells, described as macrophages or immature dendritic cells, deplete arginine and impair T cell proliferation and cytokine production. Although arginase activity has been described in cancer patients, it is thought to originate from tumor cells metabolizing arginine to ornithine needed to sustain rapid cell proliferation. The goal of this study was to determine whether myeloid suppressor cells producing high arginase existed in renal cell carcinoma patients. Peripheral blood mononuclear cells from 123 patients with metastatic renal cell carcinoma, prior to treatment, were found to have a significantly increased arginase activity. These patients had a markedly decreased cytokine production and expressed low levels of T cell receptor CD3ζ chain. Cell separation studies showed that the increased arginase activity was limited to a specific subset of CD11b+, CD14−, CD15+ cells with a polymorphonuclear granulocyte morphology and markers, instead of macrophages or dendritic cells described in mouse models. Furthermore, these patients had low levels of arginine and high levels of ornithine in plasma. Depletion of the CD11b+, CD14− myeloid suppressor cells reestablished T cell proliferation and CD3ζ chain expression. These results showed, for the first time, the existence of suppressor myeloid cells producing arginase in human cancer patients. In addition, it supports the concept that blocking arginase may be an important step in the success of immunotherapy.

Supplementary Information from Arginase-Producing Myeloid Suppressor Cells in Renal Cell Carcinoma Patients: A Mechanism of Tumor Evasion

Metaplastic breast carcinoma (MBC) is a rare breast cancer subtype with rapid growth, high rates of metastasis, recurrence and drug resistance, and diverse molecular and histological heterogeneity. Patient-derived xenografts (PDXs) provide a translational tool and physiologically relevant system to evaluate tumor biology of rare subtypes. Here, we provide an in-depth comprehensive characterization of a new PDX model for MBC, TU-BcX-4IC. TU-BcX-4IC is a clinically aggressive tumor exhibiting rapid growth in vivo, spontaneous metastases, and elevated levels of cell-free DNA and circulating tumor cell DNA. Relative chemosensitivity of primary cells derived from TU-BcX-4IC was performed using the National Cancer Institute (NCI) oncology drug set, crystal violet staining, and cytotoxic live/dead immunofluorescence stains in adherent and organoid culture conditions. We employed novel spheroid/organoid incubation methods (Pu·MA system) to demonstrate that TU-BcX-4IC is resistant to paclitaxel. An innovative physiologically relevant system using human adipose tissue was used to evaluate presence of cancer stem cell-like populations ex vivo. Tissue decellularization, cryogenic-scanning electron microscopy imaging and rheometry revealed consistent matrix architecture and stiffness were consistent despite serial transplantation. Matrix-associated gene pathways were essentially unchanged with serial passages, as determined by qPCR and RNA sequencing, suggesting utility of decellularized PDXs for in vitro screens. We determined type V collagen to be present throughout all serial passage of TU-BcX-4IC tumor, suggesting it is required for tumor maintenance and is a potential viable target for MBC. In this study we introduce an innovative and translational model system to study cell–matrix interactions in rare cancer types using higher passage PDX tissue.

Since 2018, we have evaluated the effectiveness of various teaching technologies for training young investigators on translational research in cancer health disparities. The Southeast Partnership for Improving Research and Training in Cancer Health Disparities (SPIRIT-CHD) unites Moffitt Cancer Center and the Louisiana State University Health Sciences Center. One of the main components of the SPIRIT-CHD is the Cancer Research Education Program (CREP) for training undergraduate and medical students from underrepresented backgrounds. The CREP utilizes a web-based didactic curriculum to engage students at both institutions in biobanking, precision medicine, and cancer health disparities topics. We report experiences from our cross-institutional cancer education program, specifically evaluating the cohorts’ satisfaction and learning gains using various communication technologies and instructional approaches. Trainees completed a survey with questions evaluating the curriculum and technology. Trainees reported satisfaction with the flipped classroom model (FCM) content and overall program (mean score = 3.2, SD = 0.79), and would recommend the program to peers. Yet, despite improved program delivery, trainees felt interaction between the two sites (mean score = 1.5, SD = 0.85) and engagement with faculty (mean score = 2.80, SD = 1.14) could be improved. The technology with the highest reported use was e-mail, with a mean score of 4.6 (SD = 0.52). LinkedIn and Twitter had the lowest frequency of use with mean scores at 1.90 (SD = 0.99) and 1.30 (SD = 1.34). Our study highlights the successes and challenges of remote learning using technology to increase interaction and engagement among trainees and faculty in a multi-site cancer research training program.

Background Systemic lupus erythematosus (SLE) is characterized by a wide spectrum of clinical and immunological abnormalities. New data have emerged about the role of inflammasomes in autoimmune diseases. We aimed to investigate whether basal inflammasome activation occurs in SLE patients, and whether a relationship between inflammasome-related-cytokines and disease activity exists. Methods Fourteen (14) consecutive SLE patients and 13 healthy individuals, matched by sex, age and ethnicity, were included. Demographics, laboratory and clinical data were recorded. Peripheral blood mononuclear cells (PBMCs) from patients and controls were obtained and monocytes were isolated by negative selection. Purified monocytes were stimulated with LPS in the presence or absence of Caspase-1 inhibitor. CD14 and Caspase-1 expression were analyzed by flow cytometry. Cytokine levels were determined in plasma and culture supernatants by ELISA. Student's t test and Mann–Whitney tests were used for statistical analysis. Results The percentage of CD14+/Caspase-1+ was significantly higher in monocytes from SLE patients compared to normal controls (p Conclusions Monocytes from SLE patients exhibited increased inflammasome activation, characterized by high expression of Caspase-1, IL-1β and IL-18. Caspase-1 specific inhibitor decreased inflammasome activation (in vitro) by suppressing the production of IL-18.

Despite a decline in overall incidence rates for cancer in the past decade, due in part to impressive advancements in both diagnosis and treatment, breast cancer (BC) remains the leading cause of cancer-related deaths in women. BC alone accounts for ∼30% of all new cancer diagnoses in women worldwide. Triple-negative BC (TNBC), defined as having no expression of the estrogen or progesterone receptors and no amplification of the HER2 receptor, is a subtype of BC that does not benefit from the use of estrogen receptor-targeting or HER2-targeting therapies. Differences in socioeconomic factors and cell intrinsic and extrinsic characteristics have been demonstrated in Black and White TNBC patient tumors. The emergence of patient-derived xenograft (PDX) models as a surrogate, translational, and functional representation of the patient with TNBC has led to the advances in drug discovery and testing of novel targeted approaches and combination therapies. However, current established TNBC PDX models fail to represent the diverse patient population and, most importantly, the specific ethnic patient populations that have higher rates of incidence and mortality. The primary aim of this review is to emphasize the importance of using clinically relevant translatable tumor models that reflect TNBC human tumor biology and heterogeneity in high-risk patient populations. The focus is to highlight the complexity of BC as it specifically relates to the management of TNBC in Black women. We discuss the importance of utilizing PDX models to study the extracellular matrix (ECM), and the distinct differences in ECM composition and biophysical properties in Black and White women. Finally, we demonstrate the crucial importance of PDX models toward novel drug discovery in this patient population.

Simple Summary Previous studies have shown heavy intake of different alcoholic beverages affects prostate cancer (PCa) clinical outcomes differently. However, the intake patterns of specific alcoholic beverages for PCa status are understudied. The study's objective is to evaluate intake patterns of total alcohol and three types of alcoholic beverage (beer, wine, and spirits) by PCa risk and aggressiveness status. This study included 10,029 men with European ancestry (4676 non-PCa men and 5353 PCa patients). We found PCa patients had a similar total heavy alcohol intake compared with non-PCa men. However, PCa patients were likely to drink more wine and spirits than non-PCa men. Patients with aggressive PCa drank more beer but not wine and spirits. Interestingly, heavy wine intake was inversely associated with PCa aggressiveness. These findings suggest that the intake patterns of specific alcoholic beverages differ by PCa status, and this information might help develop personalized alcohol intervention for PCa patients. Background: Previous studies have shown that different alcoholic beverage types impact prostate cancer (PCa) clinical outcomes differently. However, intake patterns of specific alcoholic beverages for PCa status are understudied. The study's objective is to evaluate intake patterns of total alcohol and the three types of beverage (beer, wine, and spirits) by the PCa risk and aggressiveness status. Method: This is a cross-sectional study using 10,029 men (4676 non-PCa men and 5353 PCa patients) with European ancestry from the PCa consortium. Associations between PCa status and alcohol intake patterns (infrequent, light/moderate, and heavy) were tested using multinomial logistic regressions. Results: Intake frequency patterns of total alcohol were similar for non-PCa men and PCa patients after adjusting for demographic and other factors. However, PCa patients were more likely to drink wine (light/moderate, OR = 1.11, p = 0.018) and spirits (light/moderate, OR = 1.14, p = 0.003; and heavy, OR = 1.34, p = 0.04) than non-PCa men. Patients with aggressive PCa drank more beer than patients with non-aggressive PCa (heavy, OR = 1.48, p = 0.013). Interestingly, heavy wine intake was inversely associated with PCa aggressiveness (OR = 0.56, p = 0.009). Conclusions: The intake patterns of some alcoholic beverage types differed by PCa status. Our findings can provide valuable information for developing custom alcohol interventions for PCa patients.

Background: Interleukin 2 (IL-2) treatment is associated with proteinuria. Materials and Methods: A conditionally immortalized human podocyte cell line was used to investigate expression of the podocyte specific marker podocin, IL-2R alpha (IL-2Rα), apoptosis marker Bax, and autophagy markers LC3I AND LC3II, determined by quantitative immunoblotting, following 24, 48, and 72 hours of IL-2 stimulation, comparing them to unstimulated cells. Results: Podocin was expressed at all time points. IL-2Rα expression was increased after 24 and 72 hrs (p = 0.0014, p = 0.0139) and decreased after 48 hours (p = 0.0445). Bax, LC3I, and LC3II were increased after 24 hrs (p = 0.0094, p = 0.0016, p = 0.0004) and 48 hrs (p = 0.0072, p = 0.0024, p = 0.0087). Conclusion: Human podocytes express the IL-2R and activation results in increased autophagy and apoptosis.

IMPACT: Implementation of proteomics as a diagnostic tool for Nontuberculous mycobacteria (NTM) infection can provide a more accurate, efficient and cost-effective means for effectively diagnosing disease and enacting timely management decisions which can revolutionize patient care. OBJECTIVES/GOALS: Proteomic analysis is a proven diagnostic modality enabling rapid identification of microorganisms. We sought to apply proteomics to detect proteins unique to the most clinically relevant NTM. We then determined whether these unique proteomes could be used to successfully identify NTM species from in vitro cocktail preparations. METHODS/STUDY POPULATION: NTM reference strains for M. avium, m. intracellulare, m.chimaera, m. abscessus abscessus, m. abscessus massiliense and m. abscessus boletti were cultured in vitro and subjected to proteomic analysis using Liquid Chromatography tandem-Mass Spectrometry (LCMS). Tandem Mass Tag (TMT) data acquisition utilized an MS3 approach for data collection using Proteome Discoverer 2.4.A comparative analysis of the proteome of each of these six species was performed quantitatively using LCMS. The process was repeated for three technical replicates and analyzed using the SEQUEST algorithm. Only high scoring peptides were considered utilizing a false discovery rate (FDR) of 1%. Once species-specific proteins were identified, we validated detection in individual and mixed samples of the six reference strains. RESULTS/ANTICIPATED RESULTS: The proteomic profiling of the six NTM reference strains successfully demonstrated proteins unique to each of the MAC species and MABC subspecies. Proteomic MAC species analysis produced between 327 to 2,540 unique peptides for each of the 3 species. MABC proteomic analysis identified between 17-74 unique peptides for each of the 3 subspecies. Fifteen different mixed preparations of MAC and MABC were then subjected to LCMS analysis and compared against the proteome profiles already curated for the six strains. We accurately identified at least one NTM in the majority of the samples (10/15). In three samples (3/15), the NTM was not correctly identified; in two of the samples (2/15) we were unable to determine the identity of NTM within the preparation. Further database curation will be performed to hone these results. DISCUSSION/SIGNIFICANCE OF FINDINGS: Proteomic analysis of in vitro reference strains successfully demonstrated protein fingerprints specific to six common disease-causing strains of NTM. Such findings can be used to evaluate clinical samples enabling more efficient diagnostic specificity. Further research will focus on identification of NTM in sputum samples of infected patients.

Triple-negative breast cancers (TNBCs) constitute approximately 12% of all breast cancer cases and are approximately twice as prevalent in African-American populations. Louisiana has a high proportion of African-American residents (32.3% in 2017), and New Orleans has among the highest incidences of TNBC in the country. Louisiana patients also have a high incidence of co-morbidities that affect breast cancer biology and outcomes, including type 2 diabetes and obesity. TNBCs have an aggressive clinical presentation due to high rates of metastasis, recurrence and chemoresistance. There are currently no clinically approved targeted therapies for TNBC; cytotoxic chemotherapy is the first-line treatment for TNBC, and recurrent, chemoresistant cancers are usually fatal. TNBCs are molecularly heterogeneous, consisting of at least four molecular subgroups, and immunologically heterogeneous. Both molecular and immunologic properties are associated with clinical outcomes and are seriously understudied in patients under-represented in biomedical research. Patient-derived xenografts (PDXs), as well as patient-derived organoids (PDO), are currently the best model for translational oncology therapeutic research because they accurately recapitulate the complex architecture and heterogenous genetic and molecular composition of solid cancers. To date, the majority of TNBC research has been based on Caucasian patients, although incidence rates of TNBC are higher in African-American cohorts. Our collaborative team aims to overcome this obstacle by establishing and characterizing TNBC PDX models that represent this understudied cohort. We currently have ten TNBC PDX models representing different patient ethnicities, responsiveness to chemotherapies, as well as different TNBC molecular subtypes and metastatic behavior. We dissect and evaluate the various individual components (tumor cell biology, stroma, immune, extracellular matrix) of TNBC tumors. We utilize these models in vivo, ex vivo and in vitro to examine how unique kinases and targeted inhibitors affect the distinct tumor characteristics. In addition to in vivo treatment studies, we generated cell lines and PDOs and we utilize novel techniques such as tissue decellularization to examine extracellular matrix components. We also analyze mechanistically relevant transcript (qRT-PCR) and protein (Western blot, immunohistochemistry) expression patterns that are unique to each PDX model to evaluate the effects of targeted therapies. We work with surrounding laboratories in the greater New Orleans area (Tulane, LSU, Xavier) that are also focused on therapeutic discovery of TNBC in a collaborative effort to provide translational models for their projects. Our aim is to leverage novel PDX models from understudied patients with a range of clinical and molecular presentations to guide the selection of therapeutically targetable pathways and therapeutic agents in specific molecular subtypes of TNBC. Citation Format: Margarite D. Matossian, Steven Elliott, Hope E. Burks, Maryl Wright, Rachel A. Sabol, Van T. Hoang, Deniz A. Ucar, Alex Alfortish, Jovanny Zabaleta, Fokhrul Hossain, Tiffany Chang, Henri Wathieu, Nicholas Pashos, Bruce Bunnell, Krzysztof Moroz, Arnold Zea, Adam Riker, Steven D. Jones, Elizabeth C. Martin, Lucio Miele, Bridgette M. Collins-Burow, Matthew E. Burow. Applications of patient-derived triple-negative breast cancer xenografts that represent understudied patients in Louisiana in targeted therapeutic research [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C110.

The Southeast Partnership for Improving Research and Training in Cancer Health Disparities (SPIRIT-CHD) unites Louisiana State University Health Sciences Center (LSUHSC) and Moffitt Cancer Center (MCC) to advance translational research on cancer health disparities and to establish a Cancer Research Education Program (CREP). The CREP addresses a national priority to develop an educational training pipeline for one-on-one mentoring of undergraduates and medical students by a diverse group of LSUHSC and MCC faculty with unique expertise to conduct cancer health disparities research and outreach in underserved communities. The CREP supports 8-week internships providing: (1) hands-on summer research experiences; (2) a curriculum focusing on biobanking, precision medicine, and cancer health disparities; and (3) community outreach experiences in underserved communities. The curriculum includes web-based training modules, immersion experiences (e.g., biobank tour), professional development workshops, and learning activities (e.g., book and journal clubs). Data from the students' pre/post summative (impact/outcome) evaluations determine the acceptability and impact of these research and educational activities, students' knowledge, career aspirations, goal attainment, and their satisfaction based on nationally normed scales. Baseline and post-training data will be analyzed in August, at training completion, to assess program impact. Long-term yearly follow-up data will focus on the impact of CREP on student career trajectories. These data will help modify the CREP for years 2-4 of the SPIRIT-CHD. Seventy-five percent of the student participants in the first cohort were female. Students self-identified as Black/African American non-Hispanic (62.5%), White Hispanic (25%), and Asian non-Hispanic (12.5%). Student projects included genomic, immunologic, and cellular wet-lab research (analyzing proliferation of renal cell carcinoma, RNA sequencing and bioinformatics of Luminal B breast carcinomas, expression differences of polyamine enzymes in prostate cancer) and clinical studies (detection, prevention, and treatment of anal cancer in HIV-positive populations). Dry-lab projects focused on the analysis of Behavioral Risk Factor Surveillance System to assess policy-related trends in colorectal cancer screenings, studying the effectiveness of barbers as lay health educators for skin cancer prevention, and smoking cessation among Hispanics. CREP students also participated in cancer education outreach events to explain their projects to the communities at an elevated risk for certain types of cancer. This program has applicability to undergraduate and medical students nationwide on best practices for efficacious training in cancer health disparities, precision medicine, and biobanking. Ultimately, these efforts will enhance the diversity of the cancer research workforce, while contributing to the reduction of cancer health disparities. Citation Format: Fern Tsien, Paula Gregory, Gwendolyn Quinn, Vani N. Simmons, Z'Kera Sims, Megan E. Sutter, Ayesha Umrigar, Arnold H. Zea, Cathy Meade, Clement K. Gwede. The Cancer Research Education Program (CREP): Training the next generation of cancer health disparities researchers through the Southeast Partnership for Improving Research and Training in Cancer Health Disparities (SPIRIT-CHD) [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A065.

Triple negative breast cancers (TNBCs) are a clinically and biologically aggressive breast cancer (BC) subtype; TNBC tumors have higher rates of metastasis, relapse and acquired/inherent drug resistance. Incidence and mortality rates of TNBC are stratified based on patient ethnicity - patients with African ancestry have higher mortality rates and diagnoses of invasive cancers compared to patients representing other ethnicities. Louisiana has a high proportion of African-American residents (32.7% in 2018), and New Orleans has among the highest incidences of TNBC in the country. Many of our patients present with TNBC tumors that are partially or completely resistant to neoadjuvant chemotherapies. There are currently no clinically approved targeted therapies for TNBC. Current therapeutic discovery focused TNBC research does not aptly address the knowledge gap regarding ethnic disparity in TNBC incidence/mortality rates and TNBC biology. To date, most TNBC-related research and knowledge has been acquired from Caucasian patients, although patients with African and Hispanic ancestries represent the majority of TNBC cases. Patient-derived xenografts (PDXs) are extensively used in BC research, as they mimic complex microanatomy, oncoarchitecture, and cell-cell/cell-stroma interactions of tumors. Here, we demonstrated the unique composition of PDX tumors is not dramatically affected by serial transplantation in mice, based on molecular phenotypes (examined using qRT-PCR and RNA sequencing) and the oncoarchitecture of the extracellular matrix (based on cryogenic scanning electron microscopy). Using these models in basic research facilitates translation of laboratory findings to the clinical setting, and dramatically enhanced drug discovery research. We have established over twelve TNBC PDX models, 90% of which represent patients of African ancestry, and most of which are resistant to neoadjuvant regimens. We focus on dissecting and evaluating kinase inhibitor/targeted drug response to various individual components (tumor cell biology, stroma, immune, extracellular matrix) of chemotherapy resistant TNBC tumors. Histone deacetylase inhibitors (DACi) are a promising therapeutic agent in TNBC systems; they have been shown to suppress tumorigenesis and metastasis in TNBC through suppression of the mesenchymal phenotype in cell line-based studies. In this study we utilized various TNBC PDX models (TU-BcX-2K1, -2O0, 4IC, -4M4, -4QAN, -4QX) to assess these findings in more translational systems. Interestingly, we showed that DACi effect on tumorigenesis and metastasis varied depending on specific TNBC PDXs utilized. These data implicate specific genes/signaling pathways exist in individual patient tumors that can predict tumor responsiveness to DACi. Preliminary data using the NCI oncology drug set implicated the MEK1/2 pathway contributed to sensitization of TNBC cells. Furthermore, we found a disconnect in gene expressions that were previously shown to be affected by DACi therapy (CDH1, VIM, ZEB1, ZEB2) in various derivations of PDX models (cells, PDX-Os, ex vivo, in vivo). These findings demonstrate that testing various derivations of PDX models is crucial to parsing out specific mechanisms of targeted therapies. Our methods presented here to assess targeted drug response and drug resistance using PDX models can be applied to any area of cancer research and is not limited to breast cancer. Citation Format: Margarite Matossian, Steven Elliott, Maryl Wright, Tiffany Chang, Madlin Alzoubi, Henri Wathieu, Rachel Sabol, Alex Alfortish, Hope Burks, Van Hoang, Deniz Ucar, Gabrielle Windsor, Thomas Yan, Jovanny Zabaleta, Fokhrul Hossain, Bruce Bunnell, Krzysztof Moroz, Arnold Zea, Adam Riker, Steven Jones, Elizabeth Martin, Lucio Miele, Bridgette Collins-Burow, Matthew Burow. Effect of histone deacetylase inhibitors on patient-derived neoadjuvant chemotherapy resistant triple negative breast cancer xenografts that represent understudied patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-03-17.

Human Immunodeficiency Virus (HIV)-infected individuals are at increased risk for developing neurocognitive disorders and depression. These conditions collectively affect more than 50% of people living with HIV/AIDS and adversely impact adherence to HIV therapy. Thus, identification of early markers of neurocognitive impairment could lead to interventions that improve psychosocial functioning and slow or reverse disease progression through improved treatment adherence. Evidence has accumulated for the role and function of microRNAs in normal and pathological conditions. We have optimized a protocol to profile microRNAs in body fluids. Using this methodology, we have profiled plasma microRNA expression for 30 age-matched, HIV-infected (HIV(+) ) patients and identified highly sensitive and specific microRNA signatures distinguishing HIV(+) patients with cognitive impairment from those without cognitive impairment. These results justify follow-on studies to determine whether plasma microRNA signatures can be used as a screening or prognostic tool for HIV(+) patients with neurocognitive impairment. J. Cell. Physiol. 231: 829-836, 2016. © 2015 Wiley Periodicals, Inc.

BACKGROUND: Triple negative breast cancer (TNBC) subtypes are clinically aggressive and are treated with targeted therapeutics commonly used in other BC subtypes. The claudin-low (CL) molecular subtype of TNBC has high rates of metastases, chemoresistance and recurrence. There exists an urgent need to identify novel therapeutic targets in TNBC; however, existing models utilized in target discovery research have limitations. Patient-derived xenograft (PDX) models have emerged as superior models for target discovery experiments because they recapitulate features of patient tumors that are limited by xenograft methods. METHODS: We utilize immunohistochemistry, qRT-PCR and Western Blot to visualize tumor architecture, cellular composition, genomic and protein expressions of a new TNBC PDX model (TU-BcX-2O0). We utilize tissue decellularization techniques to examine extracellular matrix composition of TU-BcX-2O0. RESULTS: Our laboratory successfully established a TNBC PDX tumor, TU-BCX-2O0, which represents a CL-TNBC subtype and maintains this phenotype throughout subsequent passaging. We dissected TU-BCx-2O0 to examine aspects of this complex tumor that can be targeted by developing therapeutics, including specific cell populations within the tumor, the extracellular matrix, and cancer stem-like cell populations. CONCLUSIONS: Here we characterize a claudin-low TNBC patient-derived xenograft model that can be utilized for therapeutic research studies.

Polycyclic aromatic hydrocarbons (PAHs) are the products of incomplete combustion of organic materials, which are present in cigarette smoke, deep-fried food, and in natural crude oil. Since PAH-metabolites form DNA adducts and cause oxidative DNA damage, we asked if these environmental carcinogens could affect transforming potential of the human Polyomavirus JC oncoprotein, T-antigen (JCV T-antigen). We extracted DMSO soluble PAHs from Deepwater Horizon oil spill in the Gulf of Mexico (oil-PAHs), and detected several carcinogenic PAHs. The oil-PAHs were tested in exponentially growing cultures of normal mouse fibroblasts (R508), and in R508 stably expressing JCV T-antigen (R508/T). The oil-PAHs were cytotoxic only at relatively high doses (1:50-1:100 dilution), and at 1:500 dilution the growth and cell survival rates were practically unaffected. This non-toxic dose triggered however, a significant accumulation of reactive oxygen species (ROS), caused oxidative DNA damage and the formation of DNA double strand breaks (DSBs). Although oil-PAHs induced similar levels of DNA damage in R508 and R508/T cells, only T-antigen expressing cells demonstrated inhibition of high fidelity DNA repair by homologous recombination (HRR). In contrast, low-fidelity repair by non-homologous end joining (NHEJ) was unaffected. This potential mutagenic shift between DNA repair mechanisms was accompanied by a significant increase in clonal growth of R508/T cells chronically exposed to low doses of the oil-PAHs. Our results indicate for the first time carcinogenic synergy in which oil-PAHs trigger oxidative DNA damage and JCV T-antigen compromises DNA repair fidelity.

IgG4-related disease is defined as a multi-organ systemic disorder with pathological findings affecting a wide range of organ systems. The condition unifies a large number of clinical diagnoses previously considered as being confined to single organ systems. At present, several issues related to its pathophysiology remained controversial, including the natural history of the disease, the pathogenic role of IgG4, and its use as a biomarker. Glucocorticoids are considered the treatment of choice for remission induction of IgG4-related disease manifestations; however, concerns regarding duration of therapy and management of refractory disease remained to be elucidated.

Chlamydia trachomatis is an obligate intracellular pathogen that requires specific essential nutrients from the host cell, one of which is the amino acid tryptophan. In this context interferon gamma (IFNγ) is the major host protective cytokine against chlamydial infections because it induces the expression of the host enzyme, indoleamine 2,3-dioxygenase 1, that degrades tryptophan, thereby restricting bacterial replication. The mechanism by which IFNγ acts has been dissected in vitro using epithelial cell-lines such as HeLa, HEp-2, or the primary-like endocervical cell-line A2EN. All these cell-lines express the high-risk human papillomavirus oncogenes E6 & E7. While screening cell-lines to identify those suitable for C. trachomatis co-infections with other genital pathogens, we unexpectedly found that tryptophan starvation did not completely block chlamydial development in cell-lines that were HR-HPV negative, such as C33A and 293. Therefore, we tested the hypothesis that HR-HPV oncogenes modulate the effect of tryptophan starvation on chlamydial development by comparing chlamydial development in HeLa and C33A cell-lines that were both derived from cervical carcinomas. Our results indicate that during tryptophan depletion, unlike HeLa, C33A cells generate sufficient intracellular tryptophan via proteasomal activity to permit C. trachomatis replication. By generating stable derivatives of C33A that expressed HPV16 E6, E7 or E6 & E7, we found that E6 expression alone was sufficient to convert C33A cells to behave like HeLa during tryptophan starvation. The reduced tryptophan levels in HeLa cells have a biological consequence; akin to the previously described effect of IFNγ, tryptophan starvation protects C. trachomatis from clearance by doxycycline in HeLa but not C33A cells. Curiously, when compared to the known Homo sapiens proteome, the representation of tryptophan in the HR-HPV E6 & E6AP degradome is substantially lower, possibly providing a mechanism that underlies the lowered intracellular free tryptophan levels in E6-expressing cells during starvation.

Low selenium levels have been linked to a higher incidence of cancer and other diseases, including Keshan, Chagas, and Kashin-Beck, and insulin resistance. Additionally, muscle and cardiovascular disorders, immune dysfunction, cancer, neurological disorders, and endocrine function have been associated with mutations in genes encoding for selenoproteins. Selenium biology is complex, and a systems biology approach to study global metabolomics, genomics, and/or proteomics may provide important clues to examining selenium-responsive markers in circulation. In the current investigation, we applied a global proteomics approach on plasma samples collected from a previously conducted, double-blinded placebo controlled clinical study, where men were supplemented with selenized-yeast (Se-Yeast; 300 μg/day, 3.8 μmol/day) or placebo-yeast for 48 weeks. Proteomic analysis was performed by iTRAQ on 8 plasma samples from each arm at baseline and 48 weeks. A total of 161 plasma proteins were identified in both arms. Twenty-two proteins were significantly altered following Se-Yeast supplementation and thirteen proteins were significantly changed after placebo-yeast supplementation in healthy men. The differentially expressed proteins were involved in complement and coagulation pathways, immune functions, lipid metabolism, and insulin resistance. Reconstruction and analysis of protein-protein interaction network around selected proteins revealed several hub proteins. One of the interactions suggested by our analysis, PHLD-APOA4, which is involved in insulin resistance, was subsequently validated by Western blot analysis. Our systems approach illustrates a viable platform for investigating responsive proteomic profile in 'before and after' condition following Se-Yeast supplementation. The nature of proteins identified suggests that selenium may play an important role in complement and coagulation pathways, and insulin resistance.

Only a small proportion of women infected with Human Papillomavirus (HPV) develop cervical cancer. Host immune response seems to play a role eliminating the viral infection and preventing progression to cancer. Characterization of tumor infiltrating lymphocytes (TILs) in cervical pre-neoplastic lesions and cervical cancer may be helpful to understand the mechanisms that mediate this protection. The aim of this study was to determine if there are differences in the localization and density (cells/mm(2)) of CD8+ T-cells, CD4+ T-cells and Tregs (CD25 + Foxp3+) in cervical pre-neoplastic lesions and cervical cancer. Immunohistochemical analysis of sections of 96 (26 CIN1, 21 CIN2, 25 CIN3, and 24 SCC) samples revealed that regardless of CIN grades, CD8+ T-cells are more abundant than CD4+, CD25+ and Foxp3+ cells in both the stroma and epithelium. There was a higher density of CD8+ cells in the stroma of cervical cancer compared to CIN3 (OR = 4.20, 95% CI 1.2-15), CIN2 (OR = 7.86, 95% CI 1.7-36.4) and CIN1 (OR = 4.25, 95% CI 1.1-17). Studies evaluating whether these cells are recruited before or after cancer progression will be helpful to understand the role of these cells in the natural history of HPV-induced lesions.

Renal cell carcinoma (RCC) remains one of the most resistant tumors to systemic chemotherapy, radiotherapy, and immunotherapy. Despite great progress in understanding the basic biology of RCC, the rate of responses in animal models and clinical trials using interferons (IFNs) has not improved significantly. It is likely that the lack of responses can be due to the tumor's ability to develop tumor escape strategies. Currently, the use of targeted therapies has improved the clinical outcomes of patients with RCC and is associated with an increase of Th1-cytokine responses (IFNγ), indicating the importance of IFNγ in inhibiting tumor proliferation. Thus, the present study was designed to investigate a new mechanism by which IFNγ mediates direct anti-proliferative effects against murine renal cell carcinoma cell lines. When cultured RCC cell lines were exposed to murine recombinant IFNγ, a dose dependent growth inhibition in CL-2 and CL-19 cells was observed; this effect was not observed in Renca cells. Growth inhibition in CL-2 and CL-19 cell lines was associated with the intracellular induction of nitric oxide synthase (iNOS) protein, resulting in a sustained elevation of nitric oxide (NO) and citrulline, and a decrease in arginase activity. The inhibition of cell proliferation appears to be due to an arrest in the cell cycle. The results indicate that in certain RCC cell lines, IFNγ modulates L-arginine metabolism by shifting from arginase to iNOS activity, thereby developing a potent inhibitory mechanism to encumber tumor cell proliferation and survival. Elucidating the cellular events triggered by IFNγ in murine RCC cell lines will permit anti-tumor effects to be exploited in the development of new combination therapies that interfere with L-arginine metabolism to effectively combat RCC in patients.

Renal cell carcinoma (RCC) remains one of the most resistant tumors to systemic chemotherapy, radiotherapy, and immunotherapy. Despite great progress in understanding the basic biology of RCC, the rate of responses in animal models and clinical trials using interferons (IFNs) has not improved significantly. It is likely that the lack of responses can be due to the tumor's ability to develop tumor escape strategies. Currently, the use of targeted therapies has improved the clinical outcomes of patients with RCC and is associated with an increase of Th1-cytokine responses (IFNγ), indicating the importance of IFNγ in inhibiting tumor proliferation. Thus, the present study was designed to investigate a new mechanism by which IFNγ mediates direct anti-proliferative effects against murine renal cell carcinoma cell lines. When cultured RCC cell lines were exposed to murine recombinant IFNγ, a dose dependent growth inhibition in CL-2 and CL-19 cells was observed; this effect was not observed in Renca cells. Growth inhibition in CL-2 and CL-19 cell lines was associated with the intracellular induction of nitric oxide synthase (iNOS) protein, resulting in a sustained elevation of nitric oxide (NO) and citrulline, and a decrease in arginase activity. The inhibition of cell proliferation appears to be due to an arrest in the cell cycle. The results indicate that in certain RCC cell lines, IFNγ modulates L-arginine metabolism by shifting from arginase to iNOS activity, thereby developing a potent inhibitory mechanism to encumber tumor cell proliferation and survival. Elucidating the cellular events triggered by IFNγ in murine RCC cell lines will permit anti-tumor effects to be exploited in the development of new combination therapies that interfere with L-arginine metabolism to effectively combat RCC in patients.

Gamma interferon (IFN-γ) induces expression of the tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO1) in human epithelial cells, the permissive cells for the obligate intracellular bacterium Chlamydia trachomatis . IDO1 depletes tryptophan by catabolizing it to kynurenine with consequences for C. trachomatis , which is a tryptophan auxotroph. In vitro studies reveal that tryptophan depletion can result in the formation of persistent (viable but noncultivable) chlamydial forms. Here, we tested the effects of the IDO1 inhibitor, levo-1-methyl-tryptophan (L-1MT), on IFN-γ-induced C. trachomatis persistence. We found that addition of 0.2 mM L-1MT to IFN-γ-exposed infected HeLa cell cultures restricted IDO1 activity at the mid-stage (20 h postinfection [hpi]) of the chlamydial developmental cycle. This delayed tryptophan depletion until the late stage (38 hpi) of the cycle. Parallel morphological and gene expression studies indicated a consequence of the delay was a block in the induction of C. trachomatis persistence by IFN-γ. Furthermore, L-1MT addition allowed C. trachomatis to undergo secondary differentiation, albeit with limited productive multiplication of the bacterium. IFN-γ-induced persistent infections in epithelial cells have been previously reported to be more resistant to doxycycline than normal productive infections in vitro . Pertinent to this observation, we found that L-1MT significantly improved the efficacy of doxycycline in clearing persistent C. trachomatis forms. It has been postulated that persistent forms of C. trachomatis may contribute to chronic chlamydial disease. Our findings suggest that IDO1 inhibitors such as L-1MT might provide a novel means to investigate, and potentially target, persistent chlamydial forms, particularly in conjunction with conventional therapeutics.

Triple-negative breast cancers (TNBCs) constitute approximately 12% of all breast cancers, and are approximately twice more prevalent in African-American populations. Louisiana has a high proportion of African-American residents (32.5% in 2015), and among the highest incidences of TNBC in the country. Louisiana patients also have a high incidence of comorbidities that affect breast cancer biology and outcomes, including type 2 diabetes and obesity. TNBCs have an aggressive clinical presentation due to high rates of metastasis, recurrence, and chemoresistance, and targeted therapy remains elusive. Discovery of novel therapeutic targets, including a subset of previously uncharacterized kinases in TNBC could provide important insights into future targeted therapies. However, current models utilized in target discovery research are limited by the inability to accurately recapitulate the complex architecture and heterogenous genetic and molecular composition of breast cancer. Furthermore, immortalized cell lines have been selected in a two-dimensional environment and may have lost important epigenetic features of original tumors they derived from. Recently, our laboratory has successfully established four TNBC patient-derived xenograft (PDX) models representing different patient ethnicities, responsiveness to chemotherapies, and different TNBC molecular subtypes and metastatic behavior. Our primary objective was to dissect and evaluate the various individual components (tumor cell biology, stroma, immune, extracellular matrix) that drive complex interactions within TNBC tumors. We utilize these models in vivo, ex vivo, and in vitro to examine how unique kinases and small molecule inhibitors affect the distinct tumor characteristics. In addition to in vivo treatment studies we generated cell lines and mammospheres (TU-BcX-2K1, TU-BcX-2O0, TU-BcX-49S, TU-BcX-4IC), and we utilize novel techniques such as tissue decellularization to examine extracellular matrix components. We also analyze mechanistically relevant transcript (qRT-PCR) and protein (Western blot, immunohistochemistry) expression patterns that are unique to each PDX model to evaluate the effect of small-molecule inhibitors on these transcripts and proteins. Our aim is to leverage novel patient-derived models from understudied patients with a range of clinical presentations to guide the selection of therapeutically targetable pathways and molecules in specific molecular subtypes of TNBC. Citation Format: Margarite Matossian, Hope Burks, Tiffany Chang, Annie Bowles, Rachel Sabol, Van Hoang, Bruce Bunnell, Alex Alfortish, Krzysztof Moroz, Arnold Zea, Adam Riker, Steven Jones, Ayse D. Ucar Bilyeu, Fokhrul Hossain, Kristin Miller, Elizabeth Martin, Benjamen O’Donnell, Nicholas Pashos, Lucio Miele, Matthew Burow, Bridgette Collins-Burow. Application of patient-derived models from understudied patient populations to discover therapeutically targetable pathways in triple-negative breast cancer systems [abstract]. In: Proceedings of the AACR Special Conference: Advances in Breast Cancer Research; 2017 Oct 7-10; Hollywood, CA. Philadelphia (PA): AACR; Mol Cancer Res 2018;16(8_Suppl):Abstract nr A01.

Overall, triple negative breast cancers (TNBCs) constitute 12% of all breast cancers, and is approximately twice more prevalent in African-American populations. Louisiana has a high proportion of African-American residents (32.5% in 2015), and thus hosts a higher population of TNBC patients. TNBCs have an aggressive phenotype that is elusive to the targeted therapeutics used to treat other breast cancer subtypes. Certain kinase families have been extensively studied as regulators of epithelial-mesenchymal transition (EMT), a process involved in the initiation of cancer metastasis. Discovery of novel kinase targets within the subset of uncharacterized kinases could provide important insight into future targeted therapies. However, current models utilized in target discovery research are limited by the inability to accurately recapitulate the complex stromal architecture and heterogenous genetic and molecular composition of breast cancer. Furthermore, immortalized cell lines are limited to a 2D environment and over time acquire mutations that may not reflect the primary tumor. Recently, our laboratory has successfully established two TNBC patient-derived xenograft (PDX) models derived from African-American patients, and generated cell lines (TU-BCx-2K1, TU-BCx-2O0) and mammospheres. One of these models, 2O0, presents tumor architecture, cellular composition, genomic (qRT-PCR) and protein (western blot) expressions that are concordant with a claudin-low subtype, which has higher rates of metastasis and recurrence. Furthermore, we show that both TNBC models metastasize to the lungs, and exhibit molecular characteristics consistent with mesenchymal phenotypes. We utilized these translational PDX models to screen a library of small molecule inhibitors that represent a variety of kinase pathways to identify novel therapeutic targets and/or pathways that are specific to TNBC subtypes. We found in a preliminary cell morphology screen using three TNBC cell lines (MDA-MB-231, BT549, MDA-MB-157), two small molecule inhibitors that increased epithelial marker (CDH1) gene expression, suppressed mesenchymal (VIM, c-FOS, SNAI1, ZEB1) expression and/or suppressed cellular motility in transwell migration assays. We observed after ex vivo treatments with our PDX tumors the two compounds increase the epithelial marker CDH1 expression, and suppress mesenchymal markers (VIM, MMP2, c-FOS, SNAI1, ZEB1) expressions. We confirm these findings in the TU-BCx-2K1 cell line. Kinase array data revealed candidate kinases responsible for the observed EMT changes in the two compounds of interest (NEK5, NEK9, NEK1 potentially affect cell motility; SRC-family kinases, TAOK2, STK10 potentially affect EMT gene changes); we plan to utilize the PDX cell lines to characterize these kinases in EMT. We aim to ultimately discover novel therapeutic targets specific to different TNBC molecular subtypes. Citation Format: Matossian M, Burks H, Bowles A, Sabol R, Hoang V, Elliott S, Bunnell B, Zuercher W, Drewry D, Wells C, Alfortish A, Lee S, Hartono A, Jones S, Moroz K, Zea A, Burow M, Collins-Burow B. Patient-derived triple negative breast cancer xenografts as a translational model to screen for novel kinase pathways [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-05-05.

Epstein-Barr nuclear antigen 1 (EBNA1) is essential for Epstein-Barr virus to immortalize naïve B cells. EBNA1 transactivates viral promoters for genes that are necessary for immortalization when it is bound to a cluster of 20 cognate binding sites, termed the family of repeats. A region of EBNA1 from amino acids (aa) 40 to 89, termed linking region 1 (LR1), has been identified previously as being sufficient for transactivation. LR1 contains two domains that are conserved in the EBNA1 orthologs of other gamma herpesviruses. The first of these, termed unique region 1 (UR1), corresponds to aa 65 to 89 of EBNA1. UR1 is necessary for transactivation and contains a conserved recognition site for cyclic AMP-dependent protein kinase (PKA), corresponding to serine 78 of EBNA1. We have pharmacologically modulated PKA activity to determine if PKA controls EBNA1's ability to transactivate. Our results indicate that PKA activators and inhibitors do not affect transactivation by EBNA1. In addition, site-directed mutagenesis demonstrates that transactivation is not influenced by the phosphorylation status of serine 78 in the UR1 domain. The second conserved domain within LR1 is a glycine-arginine repeat, corresponding to aa 40 to 54 of EBNA1. This domain, termed ATH1, functions as an AT-hook, a DNA-binding motif found in architectural transcription factors such as HMGA1a. We demonstrate that deletion of the ATH1 domain decreases EBNA1 transactivation ability, which is consistent with a transcriptional role for ATH1. Furthermore, transactivation is restored when ATH1 is replaced by equivalent AT-hook motifs from HMGA1a. Our data strongly indicate a role for AT-hooks in EBNA1's ability to transactivate, a function necessary for EBV to immortalize naïve B-cells.

Human Immunodeficiency Virus (HIV)-infected individuals are at increased risk for developing neurocognitive disorders and depression. These conditions collectively affect more than 50% of people living with HIV/AIDS and adversely impact adherence to HIV therapy. Thus, identification of early markers of neurocognitive impairment could lead to interventions that improve psychosocial functioning and slow or reverse disease progression through improved treatment adherence. Evidence has accumulated for the role and function of microRNAs in normal and pathological conditions. We have optimized a protocol to profile microRNAs in body fluids. Using this methodology, we have profiled plasma microRNA expression for 30 age-matched, HIV-infected (HIV(+) ) patients and identified highly sensitive and specific microRNA signatures distinguishing HIV(+) patients with cognitive impairment from those without cognitive impairment. These results justify follow-on studies to determine whether plasma microRNA signatures can be used as a screening or prognostic tool for HIV(+) patients with neurocognitive impairment. J. Cell. Physiol. 231: 829-836, 2016. © 2015 Wiley Periodicals, Inc.

The present study establishes poly(ADP-ribose)polymerase's (PARP's) role in chronic asthma, demonstrates that it is activated in human asthma, increases the clinical relevance of targeting PARP for blocking or preventing chronic asthma in humans and presents olaparib as a likely candidate drug., Our laboratory established a role for poly(ADP-ribose)polymerase (PARP) in asthma. To increase the clinical significance of our studies, it is imperative to demonstrate that PARP is actually activated in human asthma, to examine whether a PARP inhibitor approved for human testing such as olaparib blocks already-established chronic asthma traits in response to house dust mite (HDM), a true human allergen, in mice and to examine whether the drug modulates human cluster of differentiation type 4 (CD4+) T-cell function. To conduct the study, human lung specimens and peripheral blood mononuclear cells (PBMCs) and a HDM-based mouse asthma model were used. Our results show that PARP is activated in PBMCs and lung tissues of asthmatics. PARP inhibition by olaparib or gene knockout blocked established asthma-like traits in mice chronically exposed to HDM including airway eosinophilia and hyper-responsiveness. These effects were linked to a marked reduction in T helper 2 (Th2) cytokine production without a prominent effect on interferon (IFN)-γ or interleukin (IL)-10. PARP inhibition prevented HDM-induced increase in overall cellularity, weight and CD4+ T-cell population in spleens of treated mice whereas it increased the T-regulatory cell population. In CD3/CD28-stimulated human CD4 +T-cells, olaparib treatment reduced Th2 cytokine production potentially by modulating GATA binding protein-3 (gata-3)/IL-4 expression while moderately affecting T-cell proliferation. PARP inhibition inconsistently increased IL-17 in HDM-exposed mice and CD3/CD28-stimulated CD4+ T cells without a concomitant increase in factors that can be influenced by IL-17. In the present study, we provide evidence for the first time that PARP-1 is activated in human asthma and that its inhibition is effective in blocking established asthma in mice.

Engagement of the T cell receptor (TCR) by antigen or anti-CD3 antibody results in a cycle of internalization and re-expression of the CD3zeta. Following internalization, CD3zeta is degraded and replaced by newly synthesized CD3zeta on the cell surface. Here, we provide evidence that availability of the amino acid L-arginine modulates the cycle of internalization and re-expression of CD3zeta and cause T cell dysfunction. T cells stimulated and cultured in presence of L-arginine, undergo the normal cycle of internalization and re-expression of CD3zeta. In contrast, T cells stimulated and cultured in absence of L-arginine, present a sustained down-regulation of CD3zeta preventing the normal expression of the TCR, exhibit a decreased proliferation, and a significantly diminished production of IFNgamma, IL5, and IL10, but not IL2. The replenishment of L-arginine recovers the expression of CD3zeta. The decreased expression of CD3zeta is not caused by a decreased CD3zeta mRNA, an increased CD3zeta degradation or T cell apoptosis.

Helicobacter pylori infects approximately half the human population. The outcomes of the infection range from gastritis to gastric cancer and appear to be associated with the immunity to H. pylori. Patients developing nonatrophic gastritis present a Th1 response without developing protective immunity, suggesting that this bacterium may have mechanisms to evade the immune response of the host. Several H. pylori proteins can impair macrophage and T cell function in vitro through mechanisms that are poorly understood. We tested the effect of H. pylori extracts and live H. pylori on Jurkat cells and freshly isolated human normal T lymphocytes to identify possible mechanisms by which the bacteria might impair T cell function. Jurkat cells or activated T lymphocytes cultured with an H. pylori sonicate had a reduced proliferation that was not caused by T cell apoptosis or impairment in the early T cell signaling events. Instead, both the H. pylori sonicate and live H. pylori induced a decreased expression of the CD3ζ-chain of the TCR. Coculture of live H. pylori with T cells demonstrated that the wild-type strain, but not the arginase mutant rocF(−), depleted l-arginine and caused a decrease in CD3ζ expression. Furthermore, arginase inhibitors reversed these events. These results suggest that H. pylori arginase is not only important for urea production, but may also impair T cell function during infection.

l-Arginine plays a central role in the normal function of several organs including the immune system. It is metabolized in macrophages by inducible nitric oxide synthase to produce nitric oxide, important in the cytotoxic mechanisms, and by arginase I (ASE I) and arginase II (ASE II) to synthesize l-ornithine and urea, the first being the precursor for the production of polyamines needed for cell proliferation. l-Arginine availability can modulate T cell function. Human T cells stimulated and cultured in the absence of l-arginine lose the expression of the TCR ζ-chain (CD3ζ) and have an impaired proliferation and a decreased cytokine production. The aim of this work was to test whether activated macrophages could modulate extracellular levels of l-arginine and alter T cell function, and to determine which metabolic pathway was responsible for this event. The results show that macrophages stimulated with IL-4 + IL-13 up-regulate ASE I and cationic amino acid transporter 2B, causing a rapid reduction of extracellular levels of l-arginine and inducing decreased expression of CD3ζ and diminished proliferation in normal T lymphocytes. Competitive inhibitors of ASE I or the addition of excess l-arginine lead to the re-expression of CD3ζ and recovery of T cell proliferation. In contrast, inducible nitric oxide synthase or ASE II failed to significantly reduce the extracellular levels of l-arginine and modulate CD3ζ expression. These results may provide new insights into the mechanisms leading to T cell dysfunction and the down-regulation of CD3ζ in cancer and chronic infectious diseases.

L-Arg plays a central role in the normal function of several organ systems including the immune system. L-Arg can be depleted by arginase I produced by macrophages and hepatocytes in several disease states such as trauma and sepsis and following liver transplantation. The decrease in L-Arg levels induces a profound decrease in T cell function through mechanisms that have remained unclear. The data presented here demonstrate that Jurkat T cells cultured in medium without L-Arg (L-Arg-free RPMI) have a rapid decrease in the expression of the T cell antigen receptor zeta chain (CD3zeta), the principal signal transduction element in this receptor, and a decrease in T cell proliferation. This phenomenon is completely reversed by the replenishment of L-Arg but not other amino acids. These changes are not caused by cell apoptosis; instead, the diminished expression of CD3zeta protein is paralleled by a decrease in CD3zeta mRNA. This change in CD3zeta mRNA expression is not caused by a decrease in the transcription rate but rather by a significantly shorter CD3zeta mRNA half-life. This mechanism is sensitive to cycloheximide. Therefore, the regulation of L-Arg concentration in the microenvironment could represent an important mechanism to modulate the expression of CD3zeta and the T cell receptor and consequently of T cell function.

Nitric oxide (NO) is a key messenger involved in numerous physiological functions including inflammatory and immune responses. The functions of NO and their underlying mechanisms have been elucidated by extensive studies over the past 10 years. However, the complexity of the interactions between different levels of NO and multiple aspects of tumor development/progression as well as bacterial pathogenesis has led to apparently conflicting findings. The precise role of NO in bacterial and tumor pathogenesis involves a multitude of inter- and intracellular signaling pathways in which interferon gamma signaling and L-arginine metabolism are the major pathways involved in NO synthesis and regulation. The availability of the amino acid L-Arg can be a key factor to control the expression of inducible nitric oxide synthase (NOS2) and cellular NO levels. The role played by the NOS2/NO system both in bacterial pathogenesis and in tumor development is complex due to the dual role these molecules can play promoting or inhibiting infections and cancer. This duality brings to the table a double challenge to determine the net impact of NO on cancer or bacterial behavior and to define the therapeutic role of NO-centered anticancer or antibacterial strategies. We believe that a comprehensive and dynamic understanding of the cascade of molecular and cellular events underlying tumor biology and bacterial pathogenesis that are affected by NO will allow researchers to exploit the potential antitumor and antibacterial properties of drugs interfering with NO metabolism. The contrasting roles of NO/NOS2 in these processes are clarified in this chapter.

Introduction Cervical cancer is characterized by an immunosuppressive microenvironment and a Th2-type cytokine profile. Expression of arginase (ASE), the enzyme that converts l-arginine into l-ornithine and urea, is stimulated by Th2-type cytokines. Objective To assess the association of ASE activity and l-Arg metabolism products with cervical cancer. Methods Sera of 87 and 41 women with histologically confirmed by colposcopy-directed biopsy SCC and CIN3 respectively and 79 with normal cytology or Low-Grade Squamous Intraepithelial Lesion (LSIL), were evaluated. Cytokines were measured using Milliplex Human cytokine/chemokine kit. Arginase (ASE) activity was determined using an enzymatic assay. Levels of l-arginine, l-ornithine, putrescine and spermine were determined by HPLC. Results Significantly higher levels of ASE activity were observed in women with CIN3 (age-adjusted OR: 24.3; 95%CI: 3.82–155) and SCC (AOR: 9.8; 95%CI: 2.34–40.8). As expected, possibly due to high levels of ASE activity, higher levels of l-Arg were negatively associated with CIN3 (AOR: 0.03; 95%CI: 0.004–0.19) and SSC (AOR: 0.06; 95%CI: 0.02–0.24). Consistent with the role of ASE in the conversion of l-arginine to l-ornithine and polyamine production therefrom, women with cervical cancer had higher levels of spermine and putrescine. A correlation analysis revealed a significant albeit weak relationship between high levels of IL-10 and high levels of ASE (Pearson r=0.32, p-value=0.003) in women with cervical cancer. Conclusion This study indicates that ASE activity and l-Arg degradation mechanisms of immunosuppression are present in cervical cancer. The results foster research in the design of possible strategies to inhibit ASE activity for therapy of cervical cancer.

The natural history of genital Chlamydia trachomatis infections can vary widely; infections can spontaneously resolve but can also last from months to years, potentially progressing to cause significant pathology. The host and bacterial factors underlying this wide variation are not completely understood, but emphasize the bacterium’s capacity to evade/adapt to the genital immune response, and/or exploit local environmental conditions to survive this immune response. IFNγ is considered to be a primary host protective cytokine against endocervical C. trachomatis infections. IFNγ acts by inducing the host enzyme indoleamine 2,3-dioxygenase, which catabolizes tryptophan, thereby depriving the bacterium of this essential amino acid. In vitro studies have revealed that tryptophan deprivation causes Chlamydia to enter a viable but non-infectious growth pattern that is termed a persistent growth form, characterized by a unique morphology and gene expression pattern. Provision of tryptophan can reactivate the bacterium to the normal developmental cycle. There is a significant difference in the capacity of ocular and genital C. trachomatis serovars to counter tryptophan deprivation. The latter uniquely encode a functional tryptophan synthase to synthesize tryptophan via indole salvage, should indole be available in the infection microenvironment. In vitro studies have confirmed the capacity of indole to mitigate the effects of IFNγ; it has been suggested that a perturbed vaginal microbiome may provide a source of indole in vivo. Consistent with this hypothesis, the microbiome associated with bacterial vaginosis includes species that encode a tryptophanase to produce indole. In this review, we discuss the natural history of genital chlamydial infections, morphological and molecular changes imposed by IFNγ on Chlamydia, and finally, the microenvironmental conditions associated with vaginal co-infections that can ameliorate the effects of IFNγ on C. trachomatis.

Psoriatic arthritis (PsA) is a systemic inflammatory condition associated with psoriasis. Despite considerable heterogeneity in clinical presentation, genetic studies and animal models support the notion that PsA is a distinct disease. We aimed to characterize the PsA genotype by gene expression profile and to research the effect in gene modulation of methotrexate (MTX) and TNF-inhibitors (TNF-I) in PsA-treated patients. Nine PsA patients, according to CASPAR criteria, and three healthy controls were recruited from an outpatient rheumatology clinic. Three out of nine PsA patients were naive to treatment, three received TNF-I, and the remaining three were on MTX-monotherapy. Blood samples were collected and analyzed by human genome U95 Array-Affymetrix (GeneChip® instrument system). Identification of statistically significant differences between differentially expressed genes was determined by Mann–Whitney and t test (p

The activating properties of IL-2 and the structure of the IL-2R on human monocytes are well characterized. However, relatively little is known about the biochemical mechanisms involved in IL-2 signal transduction in these cells. We investigated the role of protein tyrosine kinases (PTKs) in the activation of monocytes by IL-2. Incubation of monocytes with the PTK inhibitor herbimycin A (HA) resulted in the dose-dependent suppression of IL-2-induced monocyte tumoricidal activity. This inhibition was rather potent, as a concentration of HA as low as 0.5 μM caused a complete abrogation of cytolytic activity. Furthermore, HA markedly suppressed the ability of IL-2 to induce IL-1β, TNF-α, IL-6, and IL-8 mRNA expression and protein secretion by monocytes. Anti-phosphotyrosine immunoblotting demonstrated that IL-2 induced a rapid and time-dependent increase in tyrosine phosphorylation of several cellular proteins of molecular masses ranging from 35 to 180 kDa. Interestingly, IL-2 caused a significant up-regulation of the constitutive levels of hck PTK mRNA and protein relative to medium-treated cells as well as an increase in p59hck tyrosine phosphorylation. Finally, we demonstrated by in vitro kinase assay that the specific activity of p59hck PTK was also induced by IL-2 in monocytes. Thus, these data show that the activation of PTKs is required for the triggering of monocyte effector and secretory functions by IL-2 and strongly suggest that p59hck is a key participant in IL-2 signaling in human monocytes.

Nitric oxide (NO) is a key messenger involved in numerous physiological functions including inflammatory and immune responses. The functions of NO and their underlying mechanisms have been elucidated by extensive studies over the past 10 years. However, the complexity of the interactions between different levels of NO and multiple aspects of tumor development/progression as well as bacterial pathogenesis has led to apparently conflicting findings. The precise role of NO in bacterial and tumor pathogenesis involves a multitude of inter- and intracellular signaling pathways in which interferon gamma signaling and L-arginine metabolism are the major pathways involved in NO synthesis and regulation. The availability of the amino acid L-Arg can be a key factor to control the expression of inducible nitric oxide synthase (NOS2) and cellular NO levels. The role played by the NOS2/NO system both in bacterial pathogenesis and in tumor development is complex due to the dual role these molecules can play promoting or inhibiting infections and cancer. This duality brings to the table a double challenge to determine the net impact of NO on cancer or bacterial behavior and to define the therapeutic role of NO-centered anticancer or antibacterial strategies. We believe that a comprehensive and dynamic understanding of the cascade of molecular and cellular events underlying tumor biology and bacterial pathogenesis that are affected by NO will allow researchers to exploit the potential antitumor and antibacterial properties of drugs interfering with NO metabolism. The contrasting roles of NO/NOS2 in these processes are clarified in this chapter.

Objective. This study analyzes the major clinical characteristics of patients with active leprosy in relation to the in vitro immune response to the T- lymphocyte activator anti-CD3. Methods. Thirty-eight patients with an established diagnosis of leprosy were classified according to the Ridley and Jopling table. Peripheral blood mononuclear cells from both lepromatous leprosy (LL) and tuberculoid leprosy (TL) patients and healthy controls were used to evaluate lymphocyte proliferation; immunoenzymatic assays were used to evaluate cytokine production (IL-I, IL-2, IL-4, IL-6, IL-10, IFN-gamma). Results. Peripheral blood mononuclear cells from both LL and TL patients displayed blastogenic responses to anti- CD3. The cytokines IL-1β, IL-6, IL-10, and IFN-γ were detected in culture supernatants. Endogenous production of IL-1s was significantly higher in cell cultures from patients with the lepromatous form of the disease compared to those with tuberculoid leprosy. Production of IL-6 in response to anti CD3 was observed in a significantly higher proportion of LL than TL patients (P = 0.0025). Gamma-interferon production did not differ between TL and LL, but a direct correlation was observed between time of multidrug treatment and IFN production in vitro (P = 0.016). Interleukin-10 was detected in culture supernatants of lymphocytes activated by anti-CD3 from both patient groups, but not from healthy controls. Conclusions. The findings of this study suggest that patients with the two distinct forms of leprosy are capable of responding to a polyclonal T-lymphocyte stimulus such as anti-CD3 and provide evidence suggestive of alterations in the immune responses mediated by cytokines that may contribute to the spectrum of disease and response to treatment.

We performed a prospective, randomized study to determine whether subcutaneous administration of interleukin-2 (IL-2) in combination with an autologous renal cell vaccine is feasible and can potentiate antitumor immunity. Seventeen patients with metastatic renal cell carcinoma underwent surgical resection with preparation of an autologous tumor cell vaccine. Patients were vaccinated intradermally twice at weakly intervals with 10(7) irradiated tumor cells plus bacillus Calmette-Guérin, and once with 10(7) tumor cells alone. Patients were randomized to one of three groups: no adjuvant IL-2, low-dose IL-2 (1.2 x 10(6) IU/m2), or high-dose IL-2 (1.2 x 10(7) IU/m2). IL-2 was administered subcutaneously on the day of vaccination and the subsequent 4 days. Immune response was monitored by delayed-type hypersensitivity (DTH) response to tumor cells as compared with normal autologous renal cells. Sixteen of 17 patients received vaccine therapy. Four patients developed cellular immunity specific for autologous tumor cells as measured by DTH responses; two had received no IL-2 and two had received high-dose IL-2. There were two partial responses (PR) noted, both in patients who received high-dose IL-2. One responding patient was DTH(+) and one was negative. A third patient who was DTH(+) after vaccination with no IL-2 had a dramatic PR after receiving IL-2 subcutaneously in a subsequent protocol. Prospective testing of response to recall antigens indicated that only 5 of 12 tested patients were positive, including both clinical responders. These data suggest that subcutaneously administered adjuvant IL-2 does not dramatically augment the immunologic response to autologous renal cell vaccines as determined by the development of tumor-specific DTH response.

Burkholderia pseudomallei is a Gram-negative, facultative intracellular bacillus and the etiologic agent of melioidosis, a severe disease in Southeast Asia and Northern Australia. Like other multidrug-resistant pathogens, the inherent antibiotic resistance of B. pseudomallei impedes treatment and highlights the need for alternative therapeutic strategies that can circumvent antimicrobial resistance mechanisms. In this work, we demonstrate that host prostaglandin E2 (PGE2) production plays a regulatory role in the pathogenesis of B. pseudomallei. PGE2 promotes B. pseudomallei intracellular survival within macrophages and bacterial virulence in a mouse model of pneumonic melioidosis. PGE2-mediated immunosuppression of macrophage bactericidal effector functions is associated with increased arginase 2 (Arg2) expression and decreased nitric oxide (NO) production. Treatment with a commercially-available COX-2 inhibitor suppresses the growth of B. pseudomallei in macrophages and affords significant protection against rapidly lethal pneumonic melioidosis when administered post-exposure to B. pseudomallei-infected mice. COX-2 inhibition may represent a novel immunotherapeutic strategy to control infection with B. pseudomallei and other intracellular pathogens., Author Summary Burkholderia pseudomallei is the etiologic agent of melioidosis, a severe disease endemic in Southeast Asia and Northern Australia. B. pseudomallei is also classified as a Tier 1 select agent due to the threat of malicious use of the organism. Treatment of melioidosis is complicated by the inherent multidrug resistance of B. pseudomallei, leading to high case fatality rates or disease relapse. New therapeutic strategies are urgently needed to improve patient survival and to protect against a deliberate release of B. pseudomallei. Immunotherapeutics that can enhance the host immune response and delay disease progression represent a significant area of research interest. A number of immunomodulatory agents delivered locally to the lung prior to B. pseudomallei infection have afforded significant protection against pulmonary disease in animal models of melioidosis; however, their protective capacity significantly wanes upon post-exposure administration. In this work, we identify the PGE2 pathway as an immunotherapeutic target in pulmonary melioidosis and show that post-exposure COX-2 inhibition provides significant protection against lethal B. pseudomallei lung infection in mice. Further research examining FDA-approved COX-2 inhibitors as post-exposure prophylaxis for B. pseudomallei is warranted, as this may represent a safe, affordable, and efficacious immunotherapeutic strategy.