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Background: γ-Secretase inhibitors (GSIs) increase B cell maturation antigen (BCMA) density on malignant plasma cells and enhance antitumour activity of BCMA chimeric antigen receptor (CAR) T cells in preclinical models. We aimed to evaluate the safety and identify the recommended phase 2 dose of BCMA CAR T cells in combination with crenigacestat (LY3039478) for individuals with relapsed or refractory multiple myeloma., Methods: We conducted a phase 1, first-in-human trial combining crenigacestat with BCMA CAR T-cells at a single cancer centre in Seattle, WA, USA. We included individuals aged 21 years or older with relapsed or refractory multiple myeloma, previous autologous stem-cell transplant or persistent disease after more than four cycles of induction therapy, and Eastern Cooperative Oncology Group performance status of 0-2, regardless of previous BCMA-targeted therapy. To assess the effect of the GSI on BCMA surface density on bone marrow plasma cells, participants received GSI during a pretreatment run-in, consisting of three doses administered 48 h apart. BCMA CAR T cells were infused at doses of 50 × 10 6 CAR T cells, 150 × 10 6 CAR T cells, 300 × 10 6 CAR T cells, and 450 × 10 6 CAR T cells (total cell dose), in combination with the 25 mg crenigacestat dosed three times a week for up to nine doses. The primary endpoints were the safety and recommended phase 2 dose of BCMA CAR T cells in combination with crenigacestat, an oral GSI. This study is registered with ClinicalTrials.gov, NCT03502577, and has met accrual goals., Findings: 19 participants were enrolled between June 1, 2018, and March 1, 2021, and one participant did not proceed with BCMA CAR T-cell infusion. 18 participants (eight [44%] men and ten [56%] women) with multiple myeloma received treatment between July 11, 2018, and April 14, 2021, with a median follow up of 36 months (95% CI 26 to not reached). The most common non-haematological adverse events of grade 3 or higher were hypophosphataemia in 14 (78%) participants, fatigue in 11 (61%), hypocalcaemia in nine (50%), and hypertension in seven (39%). Two deaths reported outside of the 28-day adverse event collection window were related to treatment. Participants were treated at doses up to 450 × 10 6 CAR + cells, and the recommended phase 2 dose was not reached., Interpretations: Combining a GSI with BCMA CAR T cells appears to be well tolerated, and crenigacestat increases target antigen density. Deep responses were observed among heavily pretreated participants with multiple myeloma who had previously received BCMA-targeted therapy and those who were naive to previous BCMA-targeted therapy. Further study of GSIs given with BCMA-targeted therapeutics is warranted in clinical trials., Funding: Juno Therapeutics-a Bristol Myers Squibb company and the National Institutes of Health., Competing Interests: Declaration of interest AJC receives research funding from Juno Therapeutics—a Bristol Myers Squibb company, Nektar, Janssen, Abbvie, Harpoon, Sanofi, Adaptive Biotechologies, and Celgene; is a consultant for Adaptive Biotechnologies, Bristol Myers Squibb, and Abbvie; and receives payment for presentations from Curio Science, DAVA Oncology, and MJH Life Sciences. XS receives research funding from Juno Therapeutics—a Bristol Myers Squibb company. MJP is a consultant for SpringWorks Therapeutics, owns stock or has stock options in Lyell Immunopharma, and is currently employed by CellPoint. CJT receives research funding from Bristol Myers Squibb; has right to receive payments from royalties for inventions licensed to third parties, including Bristol Myers Squibb; is a consultant for Caribou, Myeloid Therapeutics, Precision Biosciences, Arsenal Bio, Century Therapeutics, Allogene, Legend Bio, Nektar, Syncopation Life Sciences, Sobi, Expert Connect, Decheng Capital, Asher Bio, Genentech, and Amgen; has received payment for presentations from St Judes, Malaysian Society for Hematology, Japan Society for Transplantation and Cell Therapy, and Bristol Myers Squibb; and has stock or stock options in Caribou, Myeloid Therapeutics, Precision Biosciences, Arsenal bio, and Eureka Therapeutics. BGT receives research funding from Bristol Myers Squibb; royalties from Mustang Bio; has patents with Mustang Bio; participates on a data safety monitoring board with Mustang Bio and Proteios Technology; and has stock or stock options with Proteios Technology. ENL has research funding from GSK, Celgene, Amgen, Genentech, Beigene, and Seattle Genetics and has received payment for presentations from Curio Science, Janssen, and Pharmacyclics. SAT has stock or stock options in Bristol Myers Squibb and is a current employee of Juno Therapeutics—a Bristol Myers Squibb company. BW has research funding from Amgen, Novartis, Kite, Beam, Wugen, and Biosight and receives payment for lectures from Amgen. MS receives research funding from Mustang Bio, Bristol Myers Squibb, Pharmacyclics, Genentech, Abbvie, TG Therapeutics, BeiGene, AstraZeneca, Genmab, Morphosys, Incyte, and Vincerx; is a consultant for AbbVie, Genentech, AstraZeneca, Pharmacyclices, BeiGene, Bristol Myers Squibb, Morphosys, Incyte, Kite, Eli Lilly, Genmab, Mustang Bio, Regeneron, ADC therapeutics, Fate Therapeutics, Nurix, and MEI Pharma; and receives payment for presentations from AbbVie, Genentech, AstraZeneca, Pharmacyclics, BeiGene, Bristol Myers Squibb, Morphosys, Incyte, Kite, Eli Lilly, Genmab, Mustang Bio, Regeneron, ADC therapeutics, Fate Therapeutics, Nurix, and MEI Pharma. JG receives research funding from Sobi, Juno Therapeutics— a Bristol Myers Squibb company, Celgene—a Bristol Myers Squibb company, and Angiocrine Bioscience; is a consultant for Sobi, Legend Biotech, Janssen, Kite Pharma, and MorphoSys;, and is on an advisory board for Century Therapeutics. DGM receives research funding from Kite Pharma, Juno Therapeutics—a Bristol Myers Squibb company, Celgene, Legend Biotech, and Bristol Myers Squibb; is a consultant for A2 Biotherapeutics, Navan Technologies, Chimeric Therapeutics, Genentech, Bristol Myers Squibb, ImmmPACT Bio, and Gilead Sciences; has rights to royalties for patents licensed to Juno Therapeutics—a Bristol Myers Squibb company; serves as an advisory board member for Bristol Myers Squibb, Caribou Biosciences, Celgene, Genentech, Incyte, Janssen, Juno Therapeutics—a Bristol Myers Squibb company, Mustang Bio, Morphosys, Kite, Lilly, Novartis, and Umoja; and has stocks or stock options in A2 Biotherapeutics and Navan Technologies. SRR has research funding from the National Institutes of Health, Leukemia and Lymphoma Society, Juno Therapeutics—a Bristol Myers Squibb company, Lyelle Immunopharma, and Outpace Biosciences; has rights to royalties from Juno Therapeutics—a Bristol Myers Squibb company, Lyell Immunopharma, Deverra Therapeutics; is a consultant from Lyell Immunopharma and Adaptive Biotechnologies; has patents from Juno Therapeutics—a Bristol Myers Squibb company and Lyell Immunopharma; serves on a board of directors for Ozette Technologies; and has stocks or stock options from Lyell Immunopharma and Adaptive Biotechnologies. DJG held the sponsor-investigator investigational new drug application from the US Food and Drug Administration for this study; has obtained grants or contracts through Fred Hutchinson Cancer Center with Juno Therapeutics—a Bristol Myers Squibb company, Seattle Genetics, Janssen Biotech, SpringWorks Therapeutics, Cellectar Biosciences, The Allen Institute for Immunology, The Leukemia and Lymphoma Society, and the National Institutes of Health; is in consulting agreements with Ensoma; has served on an advisory board for GSK, Janssen Biotech, Legend Biotech, and Celgene; and has two US provisional patent applications (62/582,270 and 62/582,308) through Fred Hutchinson Cancer Center and Juno Therapeutics—a Bristol Myers Squibb company. BDS, DGC, TG, JV, VQW, AGC, and FM declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Adoptive transfer of T cells expressing chimeric antigen receptors (CAR-T) effectively treats refractory hematologic malignancies in a subset of patients but can be limited by poor T-cell expansion and persistence in vivo. Less differentiated T-cell states correlate with the capacity of CAR-T to proliferate and mediate antitumor responses, and interventions that limit tumor-specific T-cell differentiation during ex vivo manufacturing enhance efficacy. NOTCH signaling is involved in fate decisions across diverse cell lineages and in memory CD8+ T cells was reported to upregulate the transcription factor FOXM1, attenuate differentiation, and enhance proliferation and antitumor efficacy in vivo. Here, we used a cell-free culture system to provide an agonistic NOTCH1 signal during naïve CD4+ T-cell activation and CAR-T production and studied the effects on differentiation, transcription factor expression, cytokine production, and responses to tumor. NOTCH1 agonism efficiently induced a stem cell memory phenotype in CAR-T derived from naïve but not memory CD4+ T cells and upregulated expression of AhR and c-MAF, driving heightened production of interleukin-22, interleukin-10, and granzyme B. NOTCH1-agonized CD4+ CAR-T demonstrated enhanced antigen responsiveness and proliferated to strikingly higher frequencies in mice bearing human lymphoma xenografts. NOTCH1-agonized CD4+ CAR-T also provided superior help to cotransferred CD8+ CAR-T, driving improved expansion and curative antitumor responses in vivo at low CAR-T doses. Our data expand the mechanisms by which NOTCH can shape CD4+ T-cell behavior and demonstrate that activating NOTCH1 signaling during genetic modification ex vivo is a potential strategy for enhancing the function of T cells engineered with tumor-targeting receptors., (© 2022 by The American Society of Hematology.)

Chimeric antigen receptor (CAR) T cell therapy targeting B cell maturation antigen (BCMA-CARTx) is an emerging treatment for relapsed or refractory multiple myeloma (R/R MM). Here we characterize the epidemiology of infections, risk factors for infection, and pathogen-specific humoral immunity in patients receiving BCMA-CARTx for R/R MM. We performed a retrospective cohort study in 32 adults with R/R MM enrolled in 2 single-institution phase 1 clinical trials of BCMA-CARTx administered after lymphodepleting chemotherapy alone (n = 22) or with a gamma secretase inhibitor (GSI). We tested serum before and up to approximately 180 days after BCMA-CARTx for measles-specific IgG and for any viral-specific IgG using a systematic viral epitope scanning assay to describe the kinetics of total and pathogen-specific IgG levels pre- and post-BCMA-CARTx. We identified microbiologically documented infections to determine infection incidence and used Poisson regression to explore risk factors for infections within 180 days after BCMA-CARTx. Most individuals developed severe neutropenia, lymphopenia, and hypogammaglobulinemia after BCMA-CARTx. Grade ≥3 cytokine release syndrome (CRS; Lee criteria) occurred in 16% of the participants; 50% of the participants received corticosteroids and/or tocilizumab. Before BCMA-CARTx, 28 of 32 participants (88%) had an IgG <400 mg/dL, and only 5 of 27 (19%) had seropositive measles antibody titers. After BCMA-CARTx, all participants had an IgG <400 mg/dL and declining measles antibody titers; of the 5 individuals with baseline seropositive levels, 2 remained above the seroprotective threshold post-treatment. Participants with IgG MM (n = 13) had significantly fewer antibodies to a panel of viral antigens compared with participants with non-IgG MM (n = 6), both before and after BCMA-CARTx. In the first 180 days after BCMA-CARTx, 17 participants (53%) developed a total of 23 infections, of which 13 (57%) were mild-to-moderate viral infections. Serious infections were more frequent in the first 28 days post-treatment. Infections appeared to be more common in individuals with higher-grade CRS. Individuals with R/R MM have substantial deficits in humoral immunity. These data demonstrate the importance of plasma cells in maintaining long-lived pathogen-specific antibodies and suggest that BCMA-CARTx recipients need ongoing surveillance for late-onset infections. Most infections were mild-moderate severity viral infections. The incidence of early infection appears to be lower than has been reported after CD19-directed CARTx for B cell neoplasms, possibly due to differences in patient and disease characteristics and regimen-related toxicities., (Copyright © 2022 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Patients undergoing allogeneic stem cell transplantation as treatment for hematological diseases face the risk of Graft-versus-Host Disease as well as relapse. Graft-versus-Host Disease and the favorable Graft-versus-Leukemia effect are mediated by donor T cells recognizing polymorphic peptides, which are presented on the cell surface by HLA molecules and result from single nucleotide polymorphism alleles that are disparate between patient and donor. Identification of polymorphic HLA-binding peptides, designated minor histocompatibility antigens, has been a laborious procedure, and the number and scope for broad clinical use of these antigens therefore remain limited. Here, we present an optimized whole genome association approach for discovery of HLA class I minor histocompatibility antigens. T cell clones isolated from patients who responded to donor lymphocyte infusions after HLA-matched allogeneic stem cell transplantation were tested against a panel of 191 EBV-transformed B cells, which have been sequenced by the 1000 Genomes Project and selected for expression of seven common HLA class I alleles (HLA-A ∗ 01:01, A ∗ 02:01, A ∗ 03:01, B ∗ 07:02, B ∗ 08:01, C ∗ 07:01, and C ∗ 07:02). By including all polymorphisms with minor allele frequencies above 0.01, we demonstrated that the new approach allows direct discovery of minor histocompatibility antigens as exemplified by seven new antigens in eight different HLA class I alleles including one antigen in HLA-A ∗ 24:02 and HLA-A ∗ 23:01, for which the method has not been originally designed. Our new whole genome association strategy is expected to rapidly augment the repertoire of HLA class I-restricted minor histocompatibility antigens that will become available for donor selection and clinical use to predict, follow or manipulate Graft-versus-Leukemia effect and Graft-versus-Host Disease after allogeneic stem cell transplantation., (Copyright © 2020 Fuchs, Honders, van der Meijden, Adriaans, van der Lee, Pont, Monajemi, Kielbasa, ’t Hoen, van Bergen, Falkenburg and Griffioen.)

CD4 + T lymphocytes are crucial for controlling a range of innate and adaptive immune effectors. For CD8 + cytotoxic T lymphocyte (CTL) responses, CD4 + T cells can function as helpers (T H ) to amplify magnitude and functionality or as regulatory cells (T reg ) capable of profound inhibition. It is unclear what determines differentiation to these phenotypes and whether pathogens provoke alternate programs. We find that, depending on the size of initial dose, Listeria infection drives CD4 + T cells to act as T H or induces rapid polyclonal conversion to immunosuppressive T reg . Conversion to T reg depends on the TLR9 and IL-12 pathways elicited by CD8α + dendritic cell (DC) sensing of danger-associated neutrophil self-DNA. These findings resolve long-standing questions regarding the conditional requirement for T H amongst pathogens and reveal a remarkable degree of plasticity in the function of CD4 + T cells, which can be quickly converted to T reg in vivo by infection-mediated immune modulation., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

B-cell maturation antigen (BCMA) is a validated target for chimeric antigen receptor (CAR) T-cell therapy in multiple myeloma (MM). Despite promising objective response rates, most patients relapse, and low levels of BCMA on a subset of tumor cells has been suggested as a probable escape mechanism. BCMA is actively cleaved from the tumor cell surface by the ubiquitous multisubunit γ-secretase (GS) complex, which reduces ligand density on tumor cells for CAR T-cell recognition and releases a soluble BCMA (sBCMA) fragment capable of inhibiting CAR T-cell function. Sufficient sBCMA can accumulate in the bone marrow of MM patients to inhibit CAR T-cell recognition of tumor cells, and potentially limit efficacy of BCMA-directed adoptive T-cell therapy. We investigated whether blocking BCMA cleavage by small-molecule GS inhibitors (GSIs) could augment BCMA-targeted CAR T-cell therapy. We found that exposure of myeloma cell lines and patient tumor samples to GSIs markedly increased surface BCMA levels in a dose-dependent fashion, concurrently decreased sBCMA concentrations, and improved tumor recognition by CAR T cells in vitro. GSI treatment of MM tumor-bearing NOD/SCID/γc-/- mice increased BCMA expression on tumor cells, decreased sBCMA in peripheral blood, and improved antitumor efficacy of BCMA-targeted CAR T-cell therapy. Importantly, short-term GSI administration to MM patients markedly increases the percentage of BCMA+ tumor cells, and the levels of BCMA surface expression in vivo. Based on these data, a US Food and Drug Administration (FDA)-approved clinical trial has been initiated, combining GSI with concurrent BCMA CAR T-cell therapy. This trial was registered at www.clinicaltrials.gov as #NCT03502577., (© 2019 by The American Society of Hematology.)

MHC-bound peptides from aberrant proteins may be a specific immunotherapeutic target on cancer cells. Because of difficulties in identifying such antigens, viral or model antigens have so far been used to study their biological relevance. We here identify a naturally existing human T-cell epitope derived from a truncated protein. The antigenic peptide is derived from the gene TTK only through an alternative transcript containing a premature termination codon that may target the transcript for nonsense-mediated decay (NMD). This antigen is recognized by HLA-A*02:01-restricted CD8 + T cells derived from an allotransplanted leukemia patient. Functional analyses showed that these T cells failed to recognize several HLA-matched primary leukemic cells that expressed the alternative TTK transcript. Conventional antigen processing and presentation were not affected, suggesting that leukemic cells modify the generation of antigens processed from aberrant proteins. This natural TTK epitope provides insights in the source of transcripts producing antigenic epitopes in healthy and leukemic cells. Our data underscore potential pitfalls of targeting NMD-derived or other unconventionally generated epitopes as immunotherapeutic approach., (©2019 American Association for Cancer Research.)

The ability to harness a patient's immune system to target malignant cells is now transforming the treatment of many cancers, including hematologic malignancies. The adoptive transfer of T cells selected for tumor reactivity or engineered with natural or synthetic receptors has emerged as an effective modality, even for patients with tumors that are refractory to conventional therapies. The most notable example of adoptive cell therapy is with T cells engineered to express synthetic chimeric antigen receptors (CARs) that reprogram their specificity to target CD19. CAR T cells have shown remarkable antitumor activity in patients with refractory B-cell malignancies. Ongoing research is focused on understanding the mechanisms of incomplete tumor elimination, reducing toxicities, preventing antigen escape, and identifying suitable targets and strategies based on established and emerging principles of synthetic biology for extending this approach to other hematologic malignancies. This review will discuss the current status, challenges, and potential future applications of CAR T-cell therapy in hematologic malignancies., (© 2018 by The American Society of Hematology.)

Allogeneic stem cell transplantation can be a curative treatment for hematological malignancies. After HLA-matched allogeneic stem cell transplantation, beneficial anti-tumor immunity as well as detrimental side-effects can develop due to donor-derived T-cells recognizing polymorphic peptides that are presented by HLA on patient cells. Polymorphic peptides on patient cells that are recognized by specific T-cells are called minor histocompatibility antigens (MiHA), while the respective peptides in donor cells are allelic variants. MiHA can be identified by reverse strategies in which large sets of peptides are screened for T-cell recognition. In these strategies, selection of peptides by prediction algorithms may be relevant to increase the efficiency of MiHA discovery. We investigated the value of online prediction algorithms for MiHA discovery and determined the in silico characteristics of 68 autosomal HLA class I-restricted MiHA that have been identified as natural ligands by forward strategies in which T-cells from in vivo immune responses after allogeneic stem cell transplantation are used to identify the antigen. Our analysis showed that HLA class I binding was accurately predicted for 87% of MiHA of which a relatively large proportion of peptides had strong binding affinity (56%). Weak binding affinity was also predicted for a considerable number of antigens (31%) and the remaining 13% of MiHA were not predicted as HLA class I binding peptides. Besides prediction for HLA class I binding, none of the other online algorithms significantly contributed to MiHA characterization. Furthermore, we demonstrated that the majority of MiHA do not differ from their allelic variants in in silico characteristics, suggesting that allelic variants can potentially be processed and presented on the cell surface. In conclusion, our analyses revealed the in silico characteristics of 68 HLA class I-restricted MiHA and explored the value of online algorithms to predict T-cell ligands that are created by genetic variants., Competing Interests: The authors have declared that no competing interests exist.

Purpose: In HLA-matched allogeneic hematopoietic stem cell transplantation (alloSCT), donor T cells recognizing minor histocompatibility antigens (MiHAs) can mediate desired antitumor immunity as well as undesired side effects. MiHAs with hematopoiesis-restricted expression are relevant targets to augment antitumor immunity after alloSCT without side effects. To identify therapeutic MiHAs, we analyzed the in vivo immune response in a patient with strong antitumor immunity after alloSCT., Experimental Design: T-cell clones recognizing patient, but not donor, hematopoietic cells were selected for MiHA discovery by whole genome association scanning. RNA-sequence data from the GEUVADIS project were analyzed to investigate alternative transcripts, and expression patterns were determined by microarray analysis and qPCR. T-cell reactivity was measured by cytokine release and cytotoxicity., Results: T-cell clones were isolated for two HLA-B*15:01-restricted MiHA. LB-GLE1-1V is encoded by a nonsynonymous SNP in exon 6 of GLE1 For the other MiHAs, an associating SNP in intron 3 of ITGB2 was found, but no SNP disparity was present in the normal gene transcript between patient and donor. RNA-sequence analysis identified an alternative ITGB2 transcript containing part of intron 3. qPCR demonstrated that this transcript is restricted to hematopoietic cells and SNP-positive individuals. In silico translation revealed LB-ITGB2-1 as HLA-B*15:01-binding peptide, which was validated as hematopoietic MiHA by T-cell experiments., Conclusions: Whole genome and transcriptome analysis identified LB-ITGB2-1 as MiHAs encoded by an alternative transcript. Our data support the therapeutic relevance of LB-ITGB2-1 and illustrate the value of RNA-sequence analysis for discovery of immune targets encoded by alternative transcripts. Clin Cancer Res; 22(16); 4185-96. ©2016 AACR., (©2016 American Association for Cancer Research.)

Cellular immunotherapy has proven to be effective in the treatment of hematological cancers by donor lymphocyte infusion after allogeneic hematopoietic stem cell transplantation and more recently by targeted therapy with chimeric antigen or T-cell receptor-engineered T cells. However, dependent on the tissue distribution of the antigens that are targeted, anti-tumor responses can be accompanied by undesired side effects. Therefore, detailed tissue distribution analysis is essential to estimate potential efficacy and toxicity of candidate targets for immunotherapy of hematological malignancies. We performed microarray gene expression analysis of hematological malignancies of different origins, healthy hematopoietic cells and various non-hematopoietic cell types from organs that are often targeted in detrimental immune responses after allogeneic stem cell transplantation leading to graft-versus-host disease. Non-hematopoietic cells were also cultured in the presence of IFN-γ to analyze gene expression under inflammatory circumstances. Gene expression was investigated by Illumina HT12.0 microarrays and quality control analysis was performed to confirm the cell-type origin and exclude contamination of non-hematopoietic cell samples with peripheral blood cells. Microarray data were validated by quantitative RT-PCR showing strong correlations between both platforms. Detailed gene expression profiles were generated for various minor histocompatibility antigens and B-cell surface antigens to illustrate the value of the microarray dataset to estimate efficacy and toxicity of candidate targets for immunotherapy. In conclusion, our microarray database provides a relevant platform to analyze and select candidate antigens with hematopoietic (lineage)-restricted expression as potential targets for immunotherapy of hematological cancers.

Purpose: T-cell recognition of minor histocompatibility antigens (MiHA) not only plays an important role in the beneficial graft-versus-leukemia (GVL) effect of allogeneic stem cell transplantation (allo-SCT) but also mediates serious GVH complications associated with allo-SCT. Using a reverse immunology approach, we aim to develop a method enabling the identification of T-cell responses directed against predefined antigens, with the goal to select those MiHAs that can be used clinically in combination with allo-SCT., Experimental Design: In this study, we used a recently developed MiHA selection algorithm to select candidate MiHAs within the HLA-presented ligandome of transformed B cells. From the HLA-presented ligandome that predominantly consisted of monomorphic peptides, 25 polymorphic peptides with a clinically relevant allele frequency were selected. By high-throughput screening, the availability of high-avidity T cells specific for these MiHA candidates in different healthy donors was analyzed., Results: With the use of MHC multimer enrichment, analyses of expanded T cells by combinatorial coding MHC multimer flow cytometry, and subsequent single-cell cloning, positive T-cell clones directed to two new MiHA: LB-CLYBL-1Y and LB-TEP1-1S could be demonstrated, indicating the immunogenicity of these two MiHAs., Conclusions: The biologic relevance of MiHA LB-CLYBL-1Y was demonstrated by the detection of LB-CLYBL-1Y-specific T cells in a patient suffering from acute myeloid leukemia (AML) that experienced an anti-leukemic response after treatment with allo-SCT., (©2015 American Association for Cancer Research.)

Hematological malignancies often express surface HLA class II, making them attractive targets for CD4+ T cell therapy. We previously demonstrated that HLA class II ligands can be divided into DM-resistant and DM-sensitive antigens. In contrast to presentation of DM-resistant antigens, presentation of DM-sensitive antigens is suppressed by HLA-DM but can be rescued by HLA-DO. We also showed that HLA-DO expression remains low in nonhematopoietic cells under inflammatory conditions, suggesting that DM-sensitive antigens may be ideal T cell targets with a low risk for graft-versus-host disease. Here, we demonstrated that B cell malignancies often express HLA-DO and that levels are in particular high in chronic lymphocytic leukemia. Moreover, we showed that surface presentation of DM-sensitive antigens is regulated by HLA-DO, and that DM-sensitive antigens are relevant T cell targets for B cell malignancies and, especially, chronic lymphocytic leukemia. These data open the perspective to target HLA class II ligands with specific processing and presentation behavior for CD4+ T cell therapy of hematological malignancies., (Copyright © 2014 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is caused by stereotyped missense mutations in NOTCH3. Whether these mutations lead to the CADASIL phenotype via a neomorphic effect, or rather by a hypomorphic effect, is subject of debate. Here, we report two novel NOTCH3 mutations, both leading to a premature stop codon with predicted loss of NOTCH3 function. The first mutation, c.307C>T, p.Arg103*, was detected in two brothers aged 50 and 55 years, with a brain MRI and skin biopsy incompatible with CADASIL. The other mutation was found in a 40-year-old CADASIL patient compound heterozygous for a pathogenic NOTCH3 mutation (c.2129A>G, p.Tyr710Cys) and an intragenic frameshift deletion. The deletion was inherited from his father, who did not have the skin biopsy abnormalities seen in CADASIL patients. These individuals with rare NOTCH3 mutations indicate that hypomorphic NOTCH3 alleles do not cause CADASIL., (© 2013 WILEY PERIODICALS, INC.)

Background and Objective: The dissemination of methicillin-resistant Staphylococcus aureus (MRSA) in patients admitted to an Intensive Care Unit (ICU) depends, among other reasons, on the time interval between obtention of the first positive sample and the establishment of measures for contact isolation. The objective of this study was to identify the risk intervals for the spread of MRSA in ICU patients and to assess the relationship between these periods and the development of new cases of MRSA acquired in the ICU., Material and Method: Observational and prospective study, which was carried out in a 18-bed polyvalent ICU during a 49-month period (October 1998-October 2002). The exposure risk period was defined as the time elapsed between obtention of the first positive sample and contact isolation of the index case, and the window period as the time elapsed between recovery of the last negative sample to the first positive sample. Infection sources of MRSA were classified into community-acquired and hospital-acquired (nosocomial extra-ICU and nosocomial intra-ICU infections)., Results: MRSA was isolated in 69 (2.73%) of 2,531 patients admitted to the ICU during the study period and in all patients measures of contact isolation were indicated. Community-acquired MRSA was diagnosed in 9 (13%) cases, nosocomial intra-ICU in 29 (42%), and nosocomial extra-ICU in 31 (44.9%). The mean duration of the exposure risk period was 3.1 (SD 2.2) (median 3, range 0-9) days and the window period 2.9 (SD 4.6) (median 1, range 0-28) days. In 18 of the 29 cases of intra-ICU-acquired MRSA (62.1%; 95% CI, 42.3-79.3), the infection was acquired within the exposure risk and/or window periods of other patients with MRSA., Conclusions: The exposure risk periods and the window periods showed a strong relationship between detection of new cases of intra-ICU colonization and/or infection by MRSA.

Aim: To describe the frequency, characteristics and progression of critically ill patients admitted to the ICU, for whom isolation is indicated due to detection of multiresistant pathogenic bacteria, and to study the effectiveness of precautionary measures to avoid dissemination of these microorganisms., Patients and Methods: Prospective, observational, cohort study performed by a specially created working group of four nurses and an ICU specialist. The study included 55 patients in whom contact isolation was indicated (isolation rate, 15.2 per 100 patients), collected over a 16-month period., Results: The multiresistant bacteria responsible for isolation of the patients were: Pseudomonas aeruginosa (17 cases), Staphylococcus aureus (17 cases), Stenotrophomonas maltophilia (15 cases), Acinetobacter baumannii (4 cases) and extended-spectrum beta-lactamase (ESBL)- producing Enterobacteria (2 cases). Vancomycin-resistant Enterococcus spp. was not identified in any case. The mean duration of ICU isolation was 17.6 6 5.1 days (range 1-75). Multiresistant bacteria were classified as intra-ICU nosocomial in 39 cases (70.9%), extra-ICU nosocomial in 10 cases (18.2%) and community-acquired in 6 (10.9%). During the study period, no epidemic outbreak due to any of the controlled bacteria was detected. The multiresistant bacteria presented in the form of colonization in 41 cases (74.5%). The reasons for discontinuing isolation were death of the patient in 18 cases, transferal to a hospital ward (discharge from the ICU) in 19 cases, and eradication of the bacteria in 18 cases. Of the 55 patients with multiresistant bacteria, 35 (63.6%) died during hospitalization, and 23 of these (41.8%) during their stay in the ICU., Conclusions: The implementation of a working team for early detection of multiresistant pathogenic bacteria resulted in application of contact isolation in 15.2% of patients admitted. Surveillance to fulfill isolation precautions in a medical-surgical ICU achieved an absence of epidemic outbreaks due to these bacteria during the study period.

A computerized database of auditory brainstem responses (ABRs) from 'normal-hearing' volunteers is described. The database contains 'raw' responses recorded from 81 individuals; subjects varied in age from 20 to 56 years. The database is currently being used in a study to aid in the interpretation of ABRs for diagnostic purposes. Copies of the database are available over the world-wide web (http:¿¿www.engg.le.ac.uk¿abrdata).

The first comprehensive computational model of the precortical mammalian auditory system to include afferent neural processing up to the level of the dorsal acoustic stria (DAS) is described. The model consists of two scissile stages simulating (1) the cochlea and auditory nerve (AN) and (2) the dorsal cochlear nucleus (DCN). The model derives its input from a 128-channel cochlear filterbank. Cochlear transduction, rectification, logarithmic compression, and two-tone suppression functions are performed at the first stage of the simulation. The 512 artificial neurons employed model the cell at the level of transmembrane potential and have interconnections that follow closely those reported in recent anatomical and physiological studies of the cat AN and DCN. The responses of the model to pure-tone stimuli (at various sound-pressure levels) and noise stimuli (at various levels and bandwidths) are reported in detail and compare well with published results. The model is being used to investigate the representation of initial English stop consonants (differing in voice-onset time) in the DAS; this work is briefly described.