Project description:RNAseq analysis of CD8 T cells after pregnancy-induced tolerance/hypofunction. The goal of this experiment was to compare the transcriptional effect of pregnancy on naive vs. memory fetus-specific CD8 T cells. We also included naive and skin-sensitized CD8 T cells (without pregnancy) as controls.
Project description:ATAC-seq analysis of CD8 T cells after pregnancy-induced tolerance/hypofunction. The goal of this experiment was to compare the epigenetic effect of pregnancy on naive vs. memory fetus-specific CD8 T cells. We also included naive and skin-sensitized CD8 T cells (without pregnancy) as controls.
Project description:We performed a global gene expression analysis comparing intragraft tolerant CD8+ T cells from CD3 antibody-treated mice showing permanent islet graft survival to intra-graft effector CD8+ T cells isolated from untreated mice showing acute rejection of islet allografts. The objective was to emphasize the anergic profile of CD8+ T cells residing within the pancreatic islet allograft of mice rendered tolerant following CD3 antibody therapy.
Project description:Tolerance of mouse kidney allografts arises in grafts that develop regulatory Tertiary Lymphoid Organs (rTLOs). scRNAseq data and adoptive transfer of alloreactive T cells post-transplant showed that cytotoxic CD8+ T cells are reprogrammed within the accepted graft to an exhausted/regulatory-like phenotype. Establishment of rTLOs was required since adoptive transfer of alloreactive T cells prior to transplantation results in kidney allograft rejection. Despite intragraft CD8+ cells with a regulatory phenotype, they were not essential for the induction and maintenance of kidney allograft tolerance. Analysis of scRNAseq data from allograft kidneys and malignant tumors identified similar regulatory-like cell types within the T cell clusters. Induction of cytotoxic CD8+ T cell dysfunction of infiltrating cells appears to be a beneficial mechanistic pathway that protects the kidney allotransplant from rejection through a process we call “defensive tolerance.” This pathway has implications for our understanding of allotransplant tolerance and tumor resistance to host immunity.
Project description:Acute rejection episodes trigger chronic renal allograft vasculopathy. Numerous leukocytes, predominantly monocytes, accumulate in graft blood vessels during reversible acute rejection preceding chronic rejection of rat kidneys. We speculate that they contribute to transplant vasculopathy and set out to characterize them. Allogeneic renal transplantation was performed in the Fischer 344 to Lewis rat strain combination, Lewis isografts served as controls. Leukocytes were harvested by intensive perfusion of graft blood vessels and subjected to flow cytometry, quantitative RT-PCR and genome-wide transcriptional profiling. Kidneys of LEW and F344 rats were transplanted in LEW rats. Five biological replicates were performed for both isogenic and allogenic transplantation. Transcriptomes of allogenics were compared to isogenics on 5 dual-color hybridizations.
Project description:Solid organ transplant represents a potentially lifesaving procedure for patients suffering from end-stage heart, lung, liver, and kidney failure. However, rejection remains a significant source of morbidity and immunosuppressive medications have significant toxicities. Janus kinase (JAK) inhibitors are effective immunosuppressants in autoimmune diseases and graft versus host disease after allogeneic hematopoietic cell transplantation. Here we examine the role of JAK inhibition in preclinical fully major histocompatibility mismatched skin and heart allograft models. Baricitinib combined with cyclosporine A (CsA) preserved fully major histocompatibility mismatched skin grafts for the entirety of a 111-day experimental period. In baricitinib plus CsA treated mice, circulating CD4+T-bet+ T cells, CD8+T-bet+ T cells, and CD4+FOXP3+ regulatory T cells were reduced. Single cell RNA sequencing revealed a unique expression profile in immune cells in the skin of baricitinib plus CsA treated mice, including decreased inflammatory neutrophils and increased CCR2- macrophages. In a fully major histocompatibility mismatched mismatched heart allograft model, baricitinib plus CsA prevented graft rejection for the entire 28-day treatment period compared with 9 days in controls. Our findings establish that the combination of baricitinib and CsA prevents rejection in allogeneic skin and heart graft models and supports the study of JAK inhibitors in human solid organ transplantation.
Project description:Acute rejection episodes trigger chronic renal allograft vasculopathy. Numerous leukocytes, predominantly monocytes, accumulate in graft blood vessels during reversible acute rejection preceding chronic rejection of rat kidneys. We speculate that they contribute to transplant vasculopathy and set out to characterize them. Allogeneic renal transplantation was performed in the Fischer 344 to Lewis rat strain combination, Lewis isografts served as controls. Leukocytes were harvested by intensive perfusion of graft blood vessels and subjected to flow cytometry, quantitative RT-PCR and genome-wide transcriptional profiling.
Project description:Graft acceptance without the need for immunosuppressive drugs is the ultimate goal of transplantation therapy. In murine liver transplantation, allografts are accepted across major histocompatibility antigen complex barriers without the use of immunosuppressive drugs and constitute a suitable model for research on immunological rejection and tolerance. MicroRNA (miRNA) has been known to be involved in the immunological responses. In order to identify mRNAs in spontaneous liver allograft tolerance, miRNA expression in hepatic allografts was examined using this transplantation model. According to the graft pathological score and function, miR-146a, 15b, 223, 23a, 27a, 34a and 451 were upregulated compared with the expression observed in the syngeneic grafts. In contrast, miR-101a, 101b and 148a were downregulated. Our results demonstrated the alteration of miRNAs in the allografts and may indicate the role of miRNAs in the induction of tolerance after transplantation. Furthermore, our data suggest that monitoring the graft expression of novel miRNAs may allow clinicians to differentiate between rejection and tolerance. A better understanding of the tolerance inducing mechanism observed in murine hepatic allografts may provide a therapeutic strategy for attenuating allograft rejection.