Project description:Partially exhausted CD8+ T cells are associated with clinically beneficial response to Teplizumab in new onset type I diabetes (whole blood RNA-seq)
Project description:Partially exhausted CD8+ T cells are associated with clinically beneficial response to Teplizumab in new onset type I diabetes (bulk RNA-seq of sorted CD8+ T-cells)
Project description:Teplizumab is approved for delay of diagnosis of type 1 diabetes and modulates new onset disease. Compared to EBV seronegative patients, those who were EBV seropositive prior to treatment had a more robust response to drug in two clinical trials. We compared the phenotypes, transcriptomes, and development of peripheral blood cells before and after teplizumab treatment. Higher number of Tregs and “partially exhausted” CD8+ T cells were found in EBV seropositive individuals at the baseline in the TN10 and AbATE trials. Single cell transcriptomics and functional assays identified downregulation of NFB and other pathways after treatment in treated EBV seropositive patients. Among diabetes antigen specific CD8+ T cells, T cell receptor and mTOR signaling were also reduced. Impairments in function of adaptive immune cells were enhanced by teplizumab treatment in EBV seropositive individuals. Our data indicate that EBV can impair signaling pathways in immune cells, that broadly redirect cell differentiation.
Project description:Partially exhausted CD8+ T cells are associated with clinically beneficial response to Teplizumab in new onset type I diabetes (single-cell RNA-seq of sorted CD8+ T-cells)
Project description:CD8 T cells normally differentiate from resting naïve T cells into function effector and then memory CD8 T cells following acute infections. During chronic viral infections, however, virus-specific CD8 T cells often become exhausted. We used microarrays to examine the gene expression differences between naive, effector, memory and exhausted virus-specific CD8 T cells following lymphocytic choriomeningitis virus infection. Experiment Overall Design: Three or four independent samples were sorted by flow cytometry for each cell type (naive, effector, memory and exhausted) virus-specific CD8 T cells. RNA was extracted and hybridized to Affymetrix microarrays.
Project description:TGFb signaling is a major pathway associated with poor clinical outcome in patients with
advanced metastatic cancers and non-response to immune checkpoint blockade, particularly in the immune-excluded tumor phenotype. While previous pre-clinical studies demonstrated that converting tumors from an excluded to an inflamed phenotype and curative anti-tumor immunity require attenuation of both PD-L1 and TGFb signaling, the underlying cellular mechanisms remain unclear. Recent studies suggest that stem cell-like CD8 T cells (TSCL) can differentiate into non-exhausted CD8 T effector cells that drive durable anti-tumor immunity. Here, we show that TGFb and PD-L1 restrain TSCL expansion as well as replacement of progenitor exhausted and dysfunctional CD8 T cells with non-exhausted IFNghi CD8 T effector cells in the tumor microenvironment (TME). Blockade of TGFb and PD-L1 generated IFNghi CD8 T effector cells with enhanced motility, enabling both their accumulation in the TME and increased interaction with other cell types. Ensuing IFNg signaling markedly transformed myeloid, stromal, and tumor niches to yield a broadly immune-supportive ecosystem. Blocking IFNg completely abolished the effect of anti-PD-L1/ TGFb combination therapy. Our data suggest that TGFb works in concert with PD-L1 to prevent TSCL expansion and replacement of exhausted CD8 T cells with fresh CD8
T effector cells, thereby maintaining the CD8 T cell compartment in a dysfunctional state.
Project description:B7x (B7-H4 or B7S1) is the seventh member of the B7 family and the in vivo function remains largely unknown. Despite new genetic data linking the B7x gene with autoimmune diseases, how exactly it contributes to peripheral tolerance and autoimmunity is unclear. Here we showed that B7x protein was not detected on antigen-presenting cells or T cells in both human and mice, which is unique in the B7 family. As B7x protein is expressed in some peripheral cells such as pancreatic b cells, we utilized a CD8 T cell-mediated diabetes model (AI4ab) in which CD8 T cells recognize an endogenous self-antigen, and found that mice lacking B7x developed more severe diabetes than control AI4ab mice. Conversely, mice overexpressing B7x in the b cells (Rip-B7xAI4ab) were diabetes free. Furthermore, adoptive transfer of effector AI4ab CD8 T cells induced diabetes in control mice, but not in Rip-B7xAI4ab mice. Mechanistic studies revealed that pathogenic effector CD8 T cells were capable of migrating to the pancreas but failed to robustly destroy tissue when encountering local B7x in Rip-B7xAI4ab mice. Although AI4ab CD8 T cells in Rip-B7xAI4ab mice and AI4ab mice showed similar cytotoxic function, cell death, and global gene expression profiles, these cells had greater proliferation in AI4ab mice than in RIP-B7xAI4ab mice. These results suggest that B7x in nonlymphoid organs prevents peripheral autoimmunity partially through inhibiting proliferation of tissue-specific CD8 T cells and that local overexpression of B7x on pancreatic b cells is sufficient to abolish CD8 T cell-induced diabetes. AI4 mice developed T1D and Rip-B7x AI4 mice were resistant to T1D. Total RNA was collected and gene expression compared between AI4 CD8 T cells from AI4 and Rip-B7xAI4 mice.
Project description:CD8+ T cell exhaustion is a distinct differentation state resulting from chronic antigen exposure and leading to hierarchical loss of effector functions. Using a murine model of diabetes, we show that CD8+ T cells derived from the islets of diabetic mice have CD8+ T cells that are canonically exhausted and yet retain sufficient effector function to contribute to pathogenicity in autoimmune diabetes. Genetic deletion of the inhibitory receptor LAG3 restricted to only CD8+ T cells lead to accelerated disease, with LAG3 deficient CD8+ T cells having enhanced effector function and trafficking. These findings reveal a distinct role of LAG3 in restraining autoreactive CD8+ T cells and implicate LAG3 as a potential therapeutic target in autoimmunity.
Project description:While distinct NK-like CD57+ and PD-1+ CD8+ exhausted T cell populations (Tex) were both linked to beneficial immunotherapy response in autoimmune Type 1 Diabetes (T1D) patients, relationships between these cell types are poorly understood. We show that PD-1+ and CD57+ Tex populations in this context were epigenetically similar, but CD57+ Tex cells displayed unique increased chromatin accessibility of inhibitory Killer Cell Immunoglobulin-like Receptor (iKIR) and other NK cell genes. PD-1+ and CD57+ Tex also showed reciprocal expression of Inhibitory Receptors (IRs) and iKIRs accompanied by chromatin accessibility of Tcf1 and Tbet transcription factor target sites, respectively. CD57+ Tex showed unappreciated gene expression heterogeneity and shared clonal relationships with PD-1+ Tex, with these cells differentiating along four interconnected lineage trajectories: Tex-PD-1+, Tex-CD57+, Tex-Branching, and Tex-Fluid. Our findings demonstrate new relationships between Tex populations in human autoimmune disease and suggest that modulating common precursor populations may enhance response to autoimmune disease treatment.