Project description:Cellular rejection after heart transplantation imparts significant morbidity and mortality. Current immunosuppressive strategies are imperfect, target recipient T-cells, and have adverse effects. The innate immune response plays an essential role in the recruitment and activation of T-cells. Targeting the donor innate immune response would represent the earliest interventional opportunity within the immune response cascade. There is limited knowledge regarding donor immune cell types and functions in the setting of cardiac transplantation and no current therapeutics exist for targeting these cell populations. Distinct populations of donor and recipient macrophages co-exist within the transplanted heart. Donor CCR2+ macrophages are key mediators of allograft rejection and deletion of MYD88 signaling in donor macrophages is sufficient to suppress rejection and extend allograft survival. This highlights the therapeutic potential of donor heart-based interventions.
Project description:To investigate the dynamic expression of mRNAs in the regulation of acute cardiac allograft rejection, we isolated CD3+ T cells purified from spleens in C57BL/6 recipient mice.
Project description:Acute allograft rejection is a leading cause for the failure of organ allotransplantation. Identifying the genes involved in the rejection process provides clues to study the mechanisms, and to provide specific gene targets for monitoring, predicting and preventing acute allograft rejection. Using a mice model of skin acute allograft rejection and SAGE method, we analyzed gene expression in the CD4+ T cells of the mice, the cell type known to play critical roles in acute allograft rejection. Our study identifies 402 SAGE tags significantly different from these from the control. From these SAGE tags, we identified 91 increasingly and 85 decreasingly expressed genes, and many genes have not been linked with acute allograft rejection before. Functional classification of these genes shows that apoptosis, transcription regulation, cell growth and maintenance and signal transduction are among the most frequently changed functional groups. Our study provides a genome-wide view for the genes involving acute allograft rejection in the CD4+ T cells, and indicates that acute allograft rejection involves multiple genes in different functional categories. The genes identified from the study provide candidates for further studying the mechanisms and for monitoring, predicting and preventing acute allograft rejection.
Project description:Increased levels of donor-derived cell-free DNA (dd-cfDNA) in recipient plasma have been associated with acute cellular rejection (ACR) after heart transplantation. DNA sequence differences have been used to distinguish between donor and recipient cfDNA but epigenetic differences could also potentially identify dd-cfDNA. This study aimed to assess the feasibility of using ventricle-specific methylation patterns in human cfDNA as an alternative biomarker for ACR in cardiac transplantation.
Project description:In order to study the changes of liver protein level in mice with acute cardiac rejection, we established a mouse model of ectopic heart transplantation. According to the matching relationship between recipient and donor, they were divided into the following two groups: allograft group (ALLO), BALB/ C hearts were transplanted into C57BL/6J recipients with complete mismatch of major histocompatibility complex; In the syngeneic transplantation group (ISO), C57BL/6J hearts were transplanted into MHC-matched C57BL/6J recipients. On day 6 after mouse heart transplantation, livers were obtained from recipient mice in the allograft group (n = 3) and from recipient mice in the syngeneic (ISO) group (n = 3). A series of techniques such as protein extraction, enzyme digestion, TMT labeling, HPLC classification, liquid chromatography-mass spectrometry tandem analysis, database search and bioinformation analysis were used to study the quantitative proteome of samples.
Project description:The study comprises various components: Samples TD: We aims to screen out different gene expression profile in donor biopsies after revascularization , We aims to predict renal allograft dysfunction early after transplantation. Samples AR, ATN, Tx: We aim to screen out different gene expression profile in acute rejection on the kidney. We aim to screen out different gene expression profile in acute tubular necrosis on the kidney. Results from the various study components can help to diagnose renal allograft dysfunction with different causes by distinct gene expression profile. Keywords: acute rejection, acute tubular necrosis, donor biopsies, renal allograft dysfunction
Project description:Compromised renal function after renal allograft transplantation often results in anemia in the recipient. Molecular mechanisms leading to anemia during acute rejection are not fully understood; inadequate erythropoietin production and iron deficiency have been reported to be the main contributors. To increase our understanding of the molecular events underlying anemia in acute rejection, we analyzed the gene expression profiles of peripheral blood lymphocytes (PBL) from four pediatric renal allograft recipients with acute rejection and concurrent anemia, using DNA microarrays containing 9000 human cDNA clones (representing 7469 unique genes). In these anemic rejecting patients, an 'erythropoiesis cluster' of 11 down-regulated genes was identified, involved in hemoglobin transcription and synthesis, iron and folate binding and transport. Additionally, some alloimmune response genes were simultaneously down-regulated. An independent data set of 36 PBL samples, some with acute rejection and some with concurrence of acute rejection and anemia, were analyzed to support a possible association between acute rejection and anemia. In conclusion, analysis using DNA microarrays has identified a cluster of genes related to hemoglobin synthesis and/or erythropoeisis that was altered in kidneys with renal allograft rejection compared with normal kidneys. The possible relationship between alterations in the expression of this cluster, reduced renal function, the alloimmune process itself, and other influences on the renal transplant awaits further analysis.
Project description:The study comprises various components: Samples TD: We aims to screen out different gene expression profile in donor biopsies after revascularization , We aims to predict renal allograft dysfunction early after transplantation. Samples AR, ATN, Tx: We aim to screen out different gene expression profile in acute rejection on the kidney. We aim to screen out different gene expression profile in acute tubular necrosis on the kidney. Results from the various study components can help to diagnose renal allograft dysfunction with different causes by distinct gene expression profile. Keywords: acute rejection, acute tubular necrosis, donor biopsies, renal allograft dysfunction Samples AR1-AR17: This study has been accomplished with 17 patients of acute rejection on the kidney.Technical replicates: 2 replicates Samples ATN1-ATN5: This study has been accomplished with 5 patients of acute tubular necrosis on the kidney. Technical replicates: 2 replicates Samples Tx1-Tx14: This study has been accomplished with 14 patients of stable renal function on the kidney.Tecnical replicates:2 replicates(except Tx12) Samples TD1-TD12: This study has been accomplished with 12 patients of donor tissue with stable function early after transplantation on the kidney.Technical replicates: 2 replicates Samples TD13-TD21: This study has been accomplished with 9 patients of donor tissue with renal dysfunction early after transplantation on the kidney.Technical replicates: 2 replicates