Association of immune evasion in myeloid sarcomas with disease manifestation and patients’ survival
Ontology highlight
ABSTRACT: Myeloid sarcomas (MS) comprise rare extramedullary manifestations of myeloid neoplasms (MN) with poor patients’ outcome. While the clinical relevance of the tumor microenvironment (TME) is well established in many malignancies, there exists limited information in MS. Therefore, the expression of the human leukocyte antigen class I (HLA-I) antigens, HLA-I antigen processing and presenting machinery (APM) components and the composition of the tumor microenvironment (TME) were analyzed. RNAseq analysis of a subset of 10 MS patients with preserved and reduced HLA-I HC expression revealed 150 differentially expressed genes in significant reduced expression of inflammatory response genes was found in HLA-I HC high samples.
Project description:Myeloid sarcoma (MS) is a subform of acute myeloid leukemia (AML), where myeloid blasts infilitrate extramedullary tissues, a process that resembles the formation of metastases in solid tumors. RKIP has been shown to be a metastasis-suppressor gene. Identification of genes modulated by RKIP in human AML cells helps us to identify mechanisms how RKIP could be involved in the formation of MS.
Project description:Attempts to develop a therapeutic vaccine against human papillomavirus (HPV)-induced malignancies have not been clinically successful to date. One reason may be the hypoxic microenvironment present in most tumors, including cervical cancer. Hypoxia dysregulates the levels of human leukocyte antigen (HLA) class I molecules in different tumor entities, impacts function of cytotoxic T cells, and leads to decreased protein levels of the oncoproteins E6 and E7 in HPV-transformed cells. Therefore, we investigated the effect of hypoxia on the presentation of HPV16 E6- and E7-derived epitopes in cervical cancer cells and its effect on epitope-specific T cell cytotoxicity. Hypoxia induced downregulation of E7 protein levels in all analyzed cell lines, as assessed by Western blotting. However, contrary to previous reports, no perturbation of antigen presentation machinery (APM) components and HLA-A2 surface expression upon hypoxia treatment was detected by mass spectrometry and flow cytometry, respectively. Cytotoxicity assays performed in hypoxic conditions showed differential effects on the specific killing of HPV16-positive cervical cancer cells by epitope-specific CD8+ T cell lines in a donor- and peptide-specific manner. Effects of hypoxia on the expression of PD-L1 were ruled out by flow cytometry analysis. Altogether, our results suggest an intact APM, and cytotoxicity despite the decreased expression of E6 and E7, suggesting that successful immunotherapies can be developed for HPV-induced cervical cancer, especially if combined with hypoxia-alleviating measures.
Project description:Increasing evidence indicates CD4+ T cells can recognize cancer-specific antigens and control tumor growth. However, it remains difficult to predict the antigens that will be presented by human leukocyte antigen class II molecules (HLA-II) - hindering efforts to optimally target them therapeutically. Obstacles include inaccurate peptide-binding prediction and unsolved complexities of the HLA-II pathway. To address these challenges, we introduce an improved technology for discovering HLA-II binding motifs and conduct a comprehensive analysis of tumor-ligandomes to learn processing rules relevant in the tumor microenvironment (TME). We profiled HLA-II alleles and showed that binding motifs are highly sensitive to HLA-DM, a peptide loading chaperone. We also revealed that intratumoral HLA-II presentation is dominated by professional antigen presenting cells (APCs), rather than cancer cells. Integrating these observations, we developed algorithms that accurately predict APC ligandomes, including peptides from phagocytosed cancer cells. These tools and biological insights will enhance HLA-II directed cancer therapies.
Project description:LC-MS/MS-based identification of HLA-peptides is poised to provide a deep understanding of the rules underlying antigen presentation. However, a key obstacle limiting the utility of MS data is the ambiguity arising from the co-expression of multiple HLA alleles. Here, we introduce a strategy for profiling the HLA ligandome one allele at a time. By using cell lines expressing a single HLA allele, optimizing immunopurifications, and developing a novel spectral search algorithm, we identified thousands of peptides bound to 16 different HLA class I alleles. These data enabled the discovery of novel binding motifs, and an integrative analysis quantifying the contribution of factors critical to epitope presentation, such as protein cleavage and gene expression. We trained neural network prediction algorithms with our large dataset (>24,000 peptides) and outperformed algorithms trained on datasets of peptides with measured affinities. We thus demonstrate a scalable strategy for systematically learning the rules of endogenous antigen presentation.
Project description:The tumor microenvironment (TME) is a complex mixture of tumor cells, immune cells, endothelial cells and fibroblastic stroma cells (FSC). While cancer-associated fibroblasts are generally seen as a tumor-promoting entity, it is conceivable that distinct FSC populations within the TME contribute to immune-mediated tumor control. Here, we show that intra-tumoral injection of a recombinant LCMV-based vaccine vector (r3LCMV) expressing the melanocyte differentiation antigen TRP2 results in T cell-dependent eradication of melanomas. Analysis of the TME revealed that viral vector transduction precipitates activation of particular FSC subsets. Using single-cell RNA-seq analysis, we identified a Cxcl13-expressing FSC population with a pronounced immune-stimulatory signature and increased expression of the inflammatory cytokine IL-33. Genetic ablation of Il33 in Cxcl13-Cre+ FSC impeded functionality of intratumoral T cells and consequently tumor control. Thus, reprogramming of distinct FSC subsets in the TME through LCMV-based vectors efficiently promotes tumor eradication by locally sustaining the activity of tumor-specific T cells.
Project description:Sotigalimab (sotiga) is an agonistic anti-CD40 monoclonal antibody that can modulate anti-tumor immune responses. In a clinical trial of sotiga combined with neoadjuvant chemoradiation (CRT) in locally advanced esophageal/gastroesophageal junction cancer, treatment induced pathologic complete responses in 38% of patients. Using high-dimensional single cell techniques, we found that sotiga dramatically re-modeled both peripheral immune responses and the tumor microenvironment (TME), increasing components of antigen processing and presentation and altering metabolic pathways in myeloid cells. Concomitant with myeloid cell alterations, sotiga primed new T cell clonotypes, increased T cells with enhanced cytotoxic activity, and decreased the frequency of Tregs in the TME. Clinical responses were associated with both baseline and treatment-induced T cell states. These findings indicate that sotiga induces antigen presentation leading to enhanced T cell activation and clinical response, and that the immune composition of the TME at baseline is important in conferring sensitivity to this treatment approach.
Project description:Sotigalimab (sotiga) is an agonistic anti-CD40 monoclonal antibody that can modulate anti-tumor immune responses. In a clinical trial of sotiga combined with neoadjuvant chemoradiation (CRT) in locally advanced esophageal/gastroesophageal junction cancer, treatment induced pathologic complete responses in 38% of patients. Using high-dimensional single cell techniques, we found that sotiga dramatically re-modeled both peripheral immune responses and the tumor microenvironment (TME), increasing components of antigen processing and presentation and altering metabolic pathways in myeloid cells. Concomitant with myeloid cell alterations, sotiga primed new T cell clonotypes, increased T cells with enhanced cytotoxic activity, and decreased the frequency of Tregs in the TME. Clinical responses were associated with both baseline and treatment-induced T cell states. These findings indicate that sotiga induces antigen presentation leading to enhanced T cell activation and clinical response, and that the immune composition of the TME at baseline is important in conferring sensitivity to this treatment approach.
Project description:Immune recognition of tumor-expressed antigens by cytotoxic CD8+ T lymphocytes is the foundation of adoptive T-cell therapy. However, therapy-induced selective pressure can sculpt the antigenicity of tumors resulting in the outgrowth of variants that have lost the target antigen. Interestingly, tumor relapse resulting from adoptive memory T cell transfer and boosting oncolytic viral vaccination can be prevented using Class I histone deacetylase inhibitor, MS-275. We demonstrate that concomitant drug delivery subverts the phenotype and suppressive function of tumor-infiltrating myeloid cells and reprograms them with the cytotoxic capacity to directly eliminate antigen-negative tumor cells. By enhancing the production of IFNγ within the tumor microenvironment, our data suggest that MS-275 modifies the local cytokine landscape in favor of antitumor myeloid cell polarization.
Project description:<p>Plasmacytoid dendritic cells (pDC) are a subset of dendritic cells with unique immunophenotypic properties and functions. While their role in antiviral immunity through production of type I interferons is well-established, their contributions to anti-tumor immunity are less clear. While some evidence demonstrates that pDC in the tumor microenvironment (TME) may drive CD4+ T cell to become <a href="https://www.ncbi.nlm.nih.gov/gene/50943">Foxp3</a>+ T regulatory cells, little is understood about the relationship of pDC with cytotoxic CD8+ T cell, the key player in antitumor immune responses.</p> <p>In this study, we perform comprehensive immunophenotyping and functional analysis of pDC from the TME and draining lymph nodes of patients with head and neck squamous cell carcinoma (HNSCC) and identify a novel pDC subset characterized by expression of the TNF receptor superfamily member <a href="https://www.ncbi.nlm.nih.gov/gene/?term=7293">CD134 (OX40)</a>. We show that OX40 expression is expressed on intratumoral pDC in both humans and mice in a tumor-model specific fashion and that this subset of pDC enhances tumor associated-antigen (TAA)-specific CD8+ T cell responses. Through transcriptomic profiling of OX40-expressing pDC from the TME, we further characterize gene signatures unique to this pDC subset that support its role as an important immunostimulatory immune population in the TME.</p>
Project description:Tumors arise and grow despite anti-cancer immune responses. These responses can be stimulated by immunotherapies such as immune checkpoint inhibitors (e.g. anti-PD1 antibodies) and chimeric antigen receptors (CAR). Efficacy of these agents in solid tumors including colorectal cancers (CRC) is limited by immunosuppressive tumor microenvironment (TME) that prevents killing of malignant cells by cytotoxic T lymphocytes (CTL). Understanding the nature of TME-generated immunosuppression is of paramount importance. Here we report that TME elicited immunosuppression via eliminating activated CTL; this elimination required TME stress-induced downregulation of the IFNAR1 chain of type I interferon (IFN) receptor and attenuation of its signaling. Downregulation of IFNAR1 was observed in human colorectal cancers (CRC) and in mouse CRC models where it was required for efficient tumor development and progression. Stabilization of IFNAR1 on CTL improved their survival and increased anti- tumor activities of CAR T cells and PD1 inhibitors thereby providing a rationale for targeting IFNAR1 degradation for immunotherapies optimization. Two genotypes of mice were examined either 9 or 21 days post injection of MC38 colon cancer cells or MC38mRFP cells, respectively. 2-3 replicate mice were analyzed on separate arrays for each condition. 6 conditions in total were analyzed.