Project description:We performed single-cell RNA-sequencing of tumor immune infiltrates and matched peripheral blood mononuclear cells of checkpoint inhibitor (CPI)-naive stage III-IV metastatic melanoma patients. After sample collection, the same patients received CPI-treatment and their response was assessed.
Project description:Checkpoint inhibitor colitis (CPI colitis) is a frequent immune-related adverse event resulting from cancer immunotherapy that is currently treated with empiric immunosuppression such as corticosteroids. A greater understanding of the pathogenesis of CPI colitis in the steroid-refractory setting is required to develop better colitis interventions targeted to each patient. Using paired colon biopsies and blood from steroid-experienced patients with endoscopically confirmed CPI colitis, combined with control patients, we performed multiplexed single-cell transcriptomics (scRNA/TCRseq) and proteomics (CITEseq, CyTOF) to identify contributing immune and non-immune populations. In CPI colitis patient biopsies compared to healthy controls, we found enrichment of resident memory (RM) T cells in both the CD8+ and unexpectedly the CD4+ compartments, as well as cytotoxic CD8+ T cells. These 3 populations expressed exact matching TCR, suggesting that CD4+ RM and CD8+ RM T cells are clonal progenitors that give rise to tissue-destructive cytotoxic effectors. Unbiased CyTOF and confirmatory scRNAseq and CITEseq analysis identifies specific mobilized subpopulations of both cytotoxic CD8+ and CD4+ RM cells that express both activation markers CD38 and HLA-DR, underscoring their pathogenic potential. CPI colitis induces global upregulation of interferon signaling and antigen presentation, as well as epithelial-specific dysregulation of homeostatic pathways (aquaporin/solute transporters) which is shared with ulcerative colitis. However, distinct from ulcerative colitis, CPI colitis involves specific alterations in stromal cell metabolic (NAD+, tryptophan) or extracellular signaling (BMP) pathways that directly impact epithelial cell survival, arguing for distinct therapeutic targeting. Finally, endothelial cells in CPI colitis demonstrate enrichment of the integrin 47 ligand MADCAM-1 (which is targeted by anti-47 antibody vedolizumab to treat colitis). This ligand is enriched in CPI colitis patients who received TNF blockade and anti-CTLA-4, identifying subsets of patients who may be more responsive to vedolizumab treatment. This work identifies putative pathogenic resident memory and cytotoxic T cells, and non-immune stromal and endothelial populations, whose properties may nominate subsets of CPI colitis patients amenable to distinct targeting strategies.
Project description:Immune checkpoint inhibitors (ICIs) have provided tremendous clinical benefit in several cancer types. However, systemic activation of the immune system also leads to several immune-related adverse events. Of these, ICI-mediated colitis (IMC) occurs frequently and is the one with the highest absolute fatality. To improve current treatment strategies, it is important to understand the cellular mechanisms that induce this form of colitis. In this review, we discuss important pathways that are altered in IMC in mouse models and in human colon biopsy samples. This reveals a complex interplay between several types of immune cells and the gut microbiome. In addition to a mechanistic understanding, patients at risk should be identifiable before ICI therapy. Here we propose to focus on T-cell subsets that interact with bacteria after inducing epithelial damage. Especially, intestinal resident immune cells are of interest. This may lead to a better understanding of IMC and provides opportunities for prevention and management.
Project description:Checkpoint inhibitor colitis (CPI colitis) is a frequent immune-related adverse event resulting from cancer immunotherapy that is currently treated with empiric immunosuppression such as corticosteroids. A greater understanding of the pathogenesis of CPI colitis in the steroid-refractory setting is required to develop better colitis interventions targeted to each patient. Using paired colon biopsies and blood from steroid-experienced patients with endoscopically confirmed CPI colitis, combined with control patients, we performed multiplexed single-cell transcriptomics (scRNA/TCRseq) and proteomics (CITEseq, CyTOF) to identify contributing immune and non-immune populations. In CPI colitis patient biopsies compared to healthy controls, we found enrichment of resident memory (RM) T cells in both the CD8+ and unexpectedly the CD4+ compartments, as well as cytotoxic CD8+ T cells. These 3 populations expressed exact matching TCR, suggesting that CD4+ RM and CD8+ RM T cells are clonal progenitors that give rise to tissue-destructive cytotoxic effectors. Unbiased CyTOF and confirmatory scRNAseq and CITEseq analysis identifies specific mobilized subpopulations of both cytotoxic CD8+ and CD4+ RM cells that express both activation markers CD38 and HLA-DR, underscoring their pathogenic potential. CPI colitis induces global upregulation of interferon signaling and antigen presentation, as well as epithelial-specific dysregulation of homeostatic pathways (aquaporin/solute transporters) which is shared with ulcerative colitis. However, distinct from ulcerative colitis, CPI colitis involves specific alterations in stromal cell metabolic (NAD+, tryptophan) or extracellular signaling (BMP) pathways that directly impact epithelial cell survival, arguing for distinct therapeutic targeting. Finally, endothelial cells in CPI colitis demonstrate enrichment of the integrin 47 ligand MADCAM-1 (which is targeted by anti-47 antibody vedolizumab to treat colitis). This ligand is enriched in CPI colitis patients who received TNF blockade and anti-CTLA-4, identifying subsets of patients who may be more responsive to vedolizumab treatment. This work identifies putative pathogenic resident memory and cytotoxic T cells, and non-immune stromal and endothelial populations, whose properties may nominate subsets of CPI colitis patients amenable to distinct targeting strategies.
Project description:Checkpoint inhibitor colitis (CPI colitis) is a frequent immune-related adverse event resulting from cancer immunotherapy that is currently treated with empiric immunosuppression such as corticosteroids. A greater understanding of the pathogenesis of CPI colitis in the steroid-refractory setting is required to develop better colitis interventions targeted to each patient. Using paired colon biopsies and blood from steroid-experienced patients with endoscopically confirmed CPI colitis, combined with control patients, we performed multiplexed single-cell transcriptomics (scRNA/TCRseq) and proteomics (CITEseq, CyTOF) to identify contributing immune and non-immune populations. In CPI colitis patient biopsies compared to healthy controls, we found enrichment of resident memory (RM) T cells in both the CD8+ and unexpectedly the CD4+ compartments, as well as cytotoxic CD8+ T cells. These 3 populations expressed exact matching TCR, suggesting that CD4+ RM and CD8+ RM T cells are clonal progenitors that give rise to tissue-destructive cytotoxic effectors. Unbiased CyTOF and confirmatory scRNAseq and CITEseq analysis identifies specific mobilized subpopulations of both cytotoxic CD8+ and CD4+ RM cells that express both activation markers CD38 and HLA-DR, underscoring their pathogenic potential. CPI colitis induces global upregulation of interferon signaling and antigen presentation, as well as epithelial-specific dysregulation of homeostatic pathways (aquaporin/solute transporters) which is shared with ulcerative colitis. However, distinct from ulcerative colitis, CPI colitis involves specific alterations in stromal cell metabolic (NAD+, tryptophan) or extracellular signaling (BMP) pathways that directly impact epithelial cell survival, arguing for distinct therapeutic targeting. Finally, endothelial cells in CPI colitis demonstrate enrichment of the integrin 47 ligand MADCAM-1 (which is targeted by anti-47 antibody vedolizumab to treat colitis). This ligand is enriched in CPI colitis patients who received TNF blockade and anti-CTLA-4, identifying subsets of patients who may be more responsive to vedolizumab treatment. This work identifies putative pathogenic resident memory and cytotoxic T cells, and non-immune stromal and endothelial populations, whose properties may nominate subsets of CPI colitis patients amenable to distinct targeting strategies.
Project description:Transcriptomic profile comparison of an in vivo model of dual combination immune checkpoint colitis or monotherapy immune checkpoint colitis