The most frequent subtype of acute myeloid leukemia (AML) is defined by mutations in the nucleophosmin 1 (NPM1) gene. Mutated NPM1 (ΔNPM1) is an attractive target for immunotherapy, since it is an ...essential driver gene and 4 bp frameshift insertions occur in the same hotspot in 30%-35% of AMLs, resulting in a C-terminal alternative reading frame of 11 aa. By searching the HLA class I ligandome of primary AMLs, we identified multiple ΔNPM1-derived peptides. For one of these peptides, HLA-A*02:01-binding CLAVEEVSL, we searched for specific T cells in healthy individuals using peptide-HLA tetramers. Tetramer-positive CD8+ T cells were isolated and analyzed for reactivity against primary AMLs. From one clone with superior antitumor reactivity, we isolated the T cell receptor (TCR) and demonstrated specific recognition and lysis of HLA-A*02:01-positive ΔNPM1 AML after retroviral transfer to CD8+ and CD4+ T cells. Antitumor efficacy of TCR-transduced T cells was confirmed in immunodeficient mice engrafted with a human AML cell line expressing ΔNPM1. In conclusion, the data show that ΔNPM1-derived peptides are presented on AML and that CLAVEEVSL is a neoantigen that can be efficiently targeted on AML by ΔNPM1 TCR gene transfer. Immunotherapy targeting ΔNPM1 may therefore contribute to treatment of AML.
HLA class I (HLA-I) glycoproteins drive immune responses by presenting antigens to cognate CD8+ T cells. This process is often hijacked by tumors and pathogens for immune evasion. Because options for ...restoring HLA-I antigen presentation are limited, we aimed to identify druggable HLA-I pathway targets. Using iterative genome-wide screens, we uncovered that the cell surface glycosphingolipid (GSL) repertoire determines effective HLA-I antigen presentation. We show that absence of the protease SPPL3 augmented B3GNT5 enzyme activity, resulting in upregulation of surface neolacto-series GSLs. These GSLs sterically impeded antibody and receptor interactions with HLA-I and diminished CD8+ T cell activation. Furthermore, a disturbed SPPL3-B3GNT5 pathway in glioma correlated with decreased patient survival. We show that the immunomodulatory effect could be reversed through GSL synthesis inhibition using clinically approved drugs. Overall, our study identifies a GSL signature that inhibits immune recognition and represents a potential therapeutic target in cancer, infection, and autoimmunity.
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•Iterative KO screens reveal a new pathway controlling HLA-I antigen presentation•SPPL3 suppresses B3GNT5 activity affecting the cell surface GSL repertoire•B3GNT5-generated GSLs limit the capacity of HLA-I to interact with natural ligands•Inhibition of GSL synthesis in glioma enhances anti-tumor immune activation
Numerous glycosphingolipids (GSLs) are expressed at the cell surface; however, their functions remain mostly unknown. Jongsma et al. identify that the protease SPPL3 destroys the GSL synthesis enzyme B3GNT5, whose GSL products negatively affect HLA-I-mediated immune responses. This pathway represents a potential therapeutic target in cancer, infection, and autoimmunity.
The transfer of T cell receptor (TCR) genes into patient T cells is a promising approach for the treatment of both viral infections and cancer. Although efficient methods exist to identify antibodies ...for the treatment of these diseases, comparable strategies to identify TCRs have been lacking. We have developed a high-throughput DNA-based strategy to identify TCR sequences by the capture and sequencing of genomic DNA fragments encoding the TCR genes. We establish the value of this approach by assembling a large library of cancer germline tumor antigen-reactive TCRs. Furthermore, by exploiting the quantitative nature of TCR gene capture, we show the feasibility of identifying antigen-specific TCRs in oligoclonal T cell populations from either human material or TCR-humanized mice. Finally, we demonstrate the ability to identify tumor-reactive TCRs within intratumoral T cell subsets without knowledge of antigen specificities, which may be the first step toward the development of autologous TCR gene therapy to target patient-specific neoantigens in human cancer.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The Major Histocompatibility Complex class I (MHC-I) system plays a vital role in immune responses by presenting antigens to T cells. Allele specific technologies, including recombinant MHC-I ...technologies, have been extensively used in T cell analyses for COVID-19 patients and are currently used in the development of immunotherapies for cancer. However, the immense diversity of MHC-I alleles presents challenges. The genetic diversity serves as the foundation of personalized medicine, yet it also poses a potential risk of exacerbating healthcare disparities based on MHC-I alleles. To assess potential biases, we analysed (pre)clinical publications focusing on COVID-19 studies and T cell receptor (TCR)-based clinical trials. Our findings reveal an underrepresentation of MHC-I alleles associated with Asian, Australian, and African descent. Ensuring diverse representation is vital for advancing personalized medicine and global healthcare equity, transcending genetic diversity. Addressing this disparity is essential to unlock the full potential of T cells for enhancing diagnosis and treatment across all individuals.
Despite repeated associations between T cell infiltration and outcome, human ovarian cancer remains poorly responsive to immunotherapy. We report that the hallmarks of tumor recognition in ovarian ...cancer-infiltrating T cells are primarily restricted to tissue-resident memory (TRM) cells. Single-cell RNA/TCR/ATAC sequencing of 83,454 CD3+CD8+CD103+CD69+ TRM cells and immunohistochemistry of 122 high-grade serous ovarian cancers shows that only progenitor (TCF1low) tissue-resident T cells (TRMstem cells), but not recirculating TCF1+ T cells, predict ovarian cancer outcome. TRMstem cells arise from transitional recirculating T cells, which depends on antigen affinity/persistence, resulting in oligoclonal, trogocytic, effector lymphocytes that eventually become exhausted. Therefore, ovarian cancer is indeed an immunogenic disease, but that depends on ∼13% of CD8+ tumor-infiltrating T cells (∼3% of CD8+ clonotypes), which are primed against high-affinity antigens and maintain waves of effector TRM-like cells. Our results define the signature of relevant tumor-reactive T cells in human ovarian cancer, which could be applicable to other tumors with unideal mutational burden.
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•Only TRM TILs show clonal enrichment and effector activity in ovarian cancer•Stem-like TRM cells replenish effector TRM cells as they become exhausted•Intra-epithelial TCF1low TRM TILs predict human ovarian cancer outcome•Sustained ovarian cancer antigen recognition depends on ∼13% of CD8+ TILs
Anadon et al. demonstrate that human ovarian cancer-infiltrating T cells exhibiting hallmarks of sustained and active tumor antigen recognition are restricted to ∼13% of CD8+ T cells at tumor beds, corresponding to ∼3% of CD8+ clonotypes. These clonotypes represent TRM lymphocytes with a reservoir that retains features of stemness.
Adoptive transfer of T cell receptor (TCR)-transduced T cells may be an attractive strategy to target both hematological malignancies and solid tumors. By introducing a TCR, large numbers of T cells ...with defined antigen (Ag) specificity can be obtained. However, by introduction of a TCR, mixed TCR dimers can be formed. Besides the decrease in TCR expression of the introduced and endogenous TCR, these mixed TCR dimers could harbor potentially harmful specificities. In this study, we demonstrate that introduction of TCRs resulted in formation of neoreactive mixed TCR dimers, composed of the introduced TCR chains pairing with either the endogenous TCR α or β chain. Neoreactivities observed were HLA class I or class II restricted. Most neoreactive mixed TCR dimers were allo-HLA reactive; however, neoreactive mixed TCR dimers with autoreactive activity were also observed. We demonstrate that inclusion of an extra disulfide bond between the constant domains of the introduced TCR markedly reduced neoreactivity, whereas enhanced effectiveness of the introduced TCR was observed. In conclusion, TCR transfer results in the formation of neoreactive mixed TCR dimers with the potential to generate off-target effects, underlining the importance of searching for techniques to facilitate preferential pairing.
Laboratory of Experimental Hematology, Leiden University Medical Center, Leiden, The Netherlands
Correspondence: Marieke Griffioen, Dept. of Hematology, C2-R, Albinusdreef 2 2333 ZA Leiden, The ...Netherlands. E-mail: M.Griffioen{at}lumc.nl
The aim of adoptive T-cell therapy of cancer is to selectively confer immunity against tumor cells. Autoimmune side effects, however, remain a risk, emphasizing the relevance of a suicide mechanism allowing in vivo elimination of infused T cells. We investigated the use of human CD20 as suicide gene in T-lymphocytes. Potential effects of forced CD20 expression on T-cell function were investigated by comparing CD20- and mock-transduced cytomegalovirus (CMV) specific T cells for cytolysis, cytokine release and proliferation. The use of CD20 as suicide gene was investigated in CMV specific T cells and in T cells genetically modified with an antigen specific T-cell receptor. No effect of CD20 on T-cell function was observed. CD20-transduced T cells with and without co-transferred T-cell receptor were efficiently eliminated by complement dependent cytotoxicity induced by therapeutic anti-CD20 antibody rituximab. The data support the broad value of CD20 as safety switch in adoptive T-cell therapy.
Key words: gene therapy, suicide gene, donor lymphocyte infusions, T-cell receptor.
Graft-versus-host disease and graft rejection are major complications of allogeneic HLA-mismatched stem cell transplantation or organ transplantation that are caused by alloreactive T cells. Because ...a range of acute viral infections have been linked to initiating these complications, we hypothesized that the cross-reactive potential of virus-specific memory T cells to allogeneic (allo) HLA molecules may be able to mediate these complications. To analyze the allo-HLA reactivity, T cells specific for Epstein-Barr virus, cytomegalovirus, varicella zoster virus, and influenza virus were tested against a panel of HLA-typed target cells, and target cells transduced with single HLA molecules. Eighty percent of T-cell lines and 45% of virus-specific T-cell clones were shown to cross-react against allo-HLA molecules. The cross-reactivity of the CD8 and CD4 T-cell clones was directed primarily against HLA class I and II, respectively. However, a restricted number of CD8 T cells exhibited cross-reactivity to HLA class II. T-cell receptor (TCR) gene transfer confirmed that allo-HLA reactivity and virus specificity were mediated via the same TCR. These results demonstrate that a substantial proportion of virus-specific T cells exert allo-HLA reactivity, which may have important clinical implications in transplantation settings as well as adoptive transfer of third-party virus-specific T cells.
Adoptive transfer of T cells engineered with a cancer-specific T cell receptor (TCR) has demonstrated clinical benefit. However, the risk for off-target toxicity of TCRs remains a concern. Here, we ...examined the cross-reactive profile of T cell clone (7B5) with a high functional sensitivity for the hematopoietic-restricted minor histocompatibility antigen HA-2 in the context of HLA-A*02:01. HA-2pos Epstein-Barr virus-transformed B lymphoblastic cell lines (EBV-LCLs) and primary acute myeloid leukemia samples, but not hematopoietic HA-2neg samples, are effectively recognized. However, we found unexpected off-target recognition of human fibroblasts and keratinocytes not expressing the HA-2 antigen. To uncover the origin of this off-target recognition, we performed an alanine scanning approach, identifying six out of nine positions to be important for peptide recognition. This indicates a low risk for broad cross-reactivity. However, using a combinatorial peptide library scanning approach, we identified a CDH13-derived peptide activating the 7B5 T cell clone. This was confirmed by recognition of CDH13-transduced EBV-LCLs and cell subsets endogenously expressing CDH13, such as proximal tubular epithelial cells. As such, we recommend the use of a combinatorial peptide library scan followed by screening against additional cell subsets to validate TCR specificity and detect off-target toxicity due to cross-reactivity directed against unrelated peptides before selecting candidate TCRs for clinical testing.
Adoptive transfer of T cells engineered with a cancer-specific T cell receptor (TCR) has demonstrated clinical benefit. To validate TCR specificity and detect off-target toxicity before selecting candidate TCRs for clinical testing, Bijen et al. recommend the use of a combinatorial peptide library scan followed by screening against additional cell subsets.
IMPORTANCE: Uveal melanoma (UM) is an intraocular primary malignant neoplasm that often gives rise to metastatic disease for which there are no effective therapies. A substantial proportion of UMs ...express the cancer-testis antigen PRAME (preferentially expressed antigen in melanoma), which can potentially be targeted by adoptive T-cell therapy. OBJECTIVE: To determine whether there may be a rationale for PRAME-directed T-cell therapy for metastatic UM. DESIGN, SETTING, AND PARTICIPANTS: An experimental study using a retrospective cohort of 64 patients with UM (median follow-up, 62 months) was conducted from January 8, 2015, to November 20, 2016, at the Leiden University Medical Center. Clinical, histopathologic, and genetic parameters were compared between 64 PRAME-positive and PRAME-negative UMs. HLA class I restricted, PRAME-specific T cells were stimulated with UM cell lines to measure their antigen-specific reactivity against these cell lines, which were analyzed for PRAME expression by real-time quantitative polymerase chain reaction. Uveal melanoma metastases from 16 unrelated patients were assessed for PRAME expression by messenger RNA fluorescence in situ hybridization and for HLA class I expression by immunofluorescence staining. MAIN OUTCOMES AND MEASURES: Interferon γ production for antigen-specific reactivity and detection of PRAME and HLA class I expression in primary and metastatic UM. RESULTS: Of the 64 patients in the study (31 women and 33 men; mean SD age at the time of enucleation, 60.6 15.6 years), PRAME expression was negative in 35 primary UMs and positive in 29 primary UMs. Positive PRAME expression was associated with a high largest basal diameter (15.0 vs 12.0 mm; P = .005), ciliary body involvement (59% vs 26%; P = .008), and amplification of chromosome 8q (66% vs 23%; P = .002). PRAME-specific T cells reacted against 4 of 7 UM cell lines, demonstrating that T-cell reactivity correlated with PRAME expression. Metastatic UM samples were positive for PRAME messenger RNA in 11 of 16 patients and for HLA class I in 10 of 16 patients, with 8 of 16 patients demonstrating coexpression of both PRAME and HLA class I. CONCLUSIONS AND RELEVANCE: PRAME is expressed in many primary and metastatic UMs, and about half of the metastatic UMs coexpress PRAME and HLA class I. The finding that PRAME-specific T cells in this study reacted against PRAME-positive UM cell lines suggests a potential role for PRAME-directed immunotherapy for selected patients with metastatic UM.
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