Project description:Rat corneal allograft rejection models were established to investigate the effects and mechanisms of resveratrol on corneal allograft rejection after corneal transplantation.
Project description:We report a novel licensing strategy to improve the immunosuppressive capacity of MSCs. Licensing murine MSCs with TGF-β1 (TGF-β MSC) significantly improved their ability to modulate both the phenotype and secretome of inflammatory bone marrow-derived macrophages and significantly increased the numbers of regulatory T lymphocytes (Tregs) following co-culture assays. These TGF-β MSC-expanded Tregs also expressed significantly higher levels of PD-L1 and CD73, indicating enhanced suppressive potential. Detailed analysis of T lymphocyte co-cultures revealed modulation of secreted factors, most notably, elevated prostaglandin E2 (PGE2). Furthermore, TGF-β MSCs could significantly prolong rejection-free survival (69.2% acceptance rate compared to 21.4% for un-licensed MSC treated recipients) in a murine corneal allograft model. Mechanistic studies revealed that (i) therapeutic efficacy of TGF-β MSCs is Smad2/3-dependent; (ii) TGF-β MSC’s enhanced immunosuppressive capacity is contact-dependent and (iii) enhanced secretion of PGE2 (via prostaglandin EP4 receptor) by TGF-β MSCs is the predominant mediator of Treg expansion and T cell activation and is associated with corneal allograft survival. Collectively, we provide compelling evidence for the use of TGF-β1 licensing as an unconventional strategy for enhancing MSC immunosuppressive capacity.
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:Lung allograft rejection results in the accumulation of low molecular weight hyaluronic acid (LMW-HA), which further propagates inflammation and tissue injury. We have previously shown that therapeutic lymphangiogenesis in a murine model of lung allograft rejection reduced tissue LMW-HA and was associated with improved transplant outcomes. Herein we investigated the use of 4-Methylumbelliferone (4-MU), a known inhibitor of HA synthesis, to alleviate acute allograft rejection in a murine model of lung transplantation. We found that treating mice with 4-MU from day 20-30 post-transplant was sufficient to significantly improve outcomes, characterized by a reduction in T-cell mediated lung inflammation, LMW-HA content and improved pathology scores. In vitro, 4-MU directly attenuated activation, proliferation, and differentiation of naïve CD4+ T-cells into Th1 cells. As 4-MU has already been demonstrated to be safe for human use, we believe examining 4-MU for the treatment of acute lung allograft rejection may be of clinical significance.
Project description:The data set contains 67 array (lymphochip cDNA array), published in N Engl J Med 2003 Jul 10;349(2):125-38. PMID: 12853585. TITLE: Molecular heterogeneity in acute renal allograft rejection identified by DNA microarray profiling. BACKGROUND: The causes and clinical course of acute rejection vary, and it is not possible to predict graft outcome reliably on the basis of available clinical, pathological, and genetic markers. We hypothesized that previously unrecognized molecular heterogeneity might underlie some of the variability in the clinical course of acute renal allograft rejection and in its response to treatment. METHODS: We used DNA microarrays in a systematic study of gene-expression patterns in biopsy samples from normal and dysfunctional renal allografts. A combination of exploratory and supervised bioinformatic methods was used to analyze these profiles. : We found consistent differences among the gene-expression patterns associated with acute rejection, nephrotoxic effects of drugs, chronic allograft nephropathy, and normal kidneys. The gene-expression patterns associated with acute rejection suggested at least three possible distinct subtypes of acute rejection that, although indistinguishable by light microscopy, were marked by differences in immune activation and cellular proliferation. Since the gene-expression patterns pointed to substantial variation in the composition of immune infiltrates, we used immunohistochemical staining to define these subtypes further. This analysis revealed a striking association between dense CD20+ B-cell infiltrates and both clinical glucocorticoid resistance (P=0.01) and graft loss (P<0.001). CONCLUSIONS: Systematic analysis of gene-expression patterns provides a window on the biology and pathogenesis of renal allograft rejection. Biopsy samples from patients with acute rejection that are indistinguishable on conventional histologic analysis reveal extensive differences in gene expression, which are associated with differences in immunologic and cellular features and clinical course. The presence of dense clusters of B cells in a biopsy sample was strongly associated with severe graft rejection, suggesting a pivotal role of infiltrating B cells in acute rejection. A disease state experiment design type is where the state of some disease such as infection, pathology, syndrome, etc is studied. Disease State: normal vs disease Keywords: disease_state_design Using regression correlation
Project description:The data set contains 67 array (lymphochip cDNA array), published in N Engl J Med 2003 Jul 10;349(2):125-38. PMID: 12853585. TITLE: Molecular heterogeneity in acute renal allograft rejection identified by DNA microarray profiling. BACKGROUND: The causes and clinical course of acute rejection vary, and it is not possible to predict graft outcome reliably on the basis of available clinical, pathological, and genetic markers. We hypothesized that previously unrecognized molecular heterogeneity might underlie some of the variability in the clinical course of acute renal allograft rejection and in its response to treatment. METHODS: We used DNA microarrays in a systematic study of gene-expression patterns in biopsy samples from normal and dysfunctional renal allografts. A combination of exploratory and supervised bioinformatic methods was used to analyze these profiles. : We found consistent differences among the gene-expression patterns associated with acute rejection, nephrotoxic effects of drugs, chronic allograft nephropathy, and normal kidneys. The gene-expression patterns associated with acute rejection suggested at least three possible distinct subtypes of acute rejection that, although indistinguishable by light microscopy, were marked by differences in immune activation and cellular proliferation. Since the gene-expression patterns pointed to substantial variation in the composition of immune infiltrates, we used immunohistochemical staining to define these subtypes further. This analysis revealed a striking association between dense CD20+ B-cell infiltrates and both clinical glucocorticoid resistance (P=0.01) and graft loss (P<0.001). CONCLUSIONS: Systematic analysis of gene-expression patterns provides a window on the biology and pathogenesis of renal allograft rejection. Biopsy samples from patients with acute rejection that are indistinguishable on conventional histologic analysis reveal extensive differences in gene expression, which are associated with differences in immunologic and cellular features and clinical course. The presence of dense clusters of B cells in a biopsy sample was strongly associated with severe graft rejection, suggesting a pivotal role of infiltrating B cells in acute rejection. A disease state experiment design type is where the state of some disease such as infection, pathology, syndrome, etc is studied. Disease State: normal vs disease Keywords: disease_state_design
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. A disease state experiment design type is where the state of some disease such as infection, pathology, syndrome, etc is studied. Keywords: disease_state_design
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. Female mice of 6-10 week age were used for the study. BALB/c mice (H-2d) and BALB/c severe combined immunodeficient (SCID) mice were from the animal facility of Shandong University (Jinan, China). C57BL/6 (H-2b, B6) were from Vitalriveri Co. ltd (Beijing, China). Mice were maintained in a pathogen-free animal environment during the experimental process. The use of mice for the study was approved by the Institutional Animal Experimental Committee, and animal care and surgical procedures were performed in compliance with the standard animal experimental protocols of Shandong University School of Medicine. The process of generating skin acute allograft rejection followed the established procedure (12). Briefly, dorsal skin of C57BL/6 was transplanted onto the dorsal thorax of BALB/c SCID mice under sterile condition (allotransplant). As a control, dorsal skin of BALB/c mice was transplanted to BALB/c SCID mice (autotransplant). After 28 days of transplantation, CD4+ T cells were harvested from the spleens of BALB/c mice by using the mouse CD4+ T cells enrichment columns (R&D) with the purity >90% as measured by flow cytometry and 8x106 purified CD4+ T cells were adoptively injected into each transplanted mice via the lateral tail vein. The skin graft in each transplanted mice was then monitored daily. The skin graft was considered to fully reject when more than 50% of the skin became necrosis. SAGE Analysis Upon 14 days post CD4+ T cell transferring, CD4+ T cells were collected from the spleens of five mice in each group with adaptive CD4 T cell transferring using the same process described above. Total RNA was extracted from the purified cells by using Trizol reagent (Invitrogen) and mRNA was purified from the total RNA using oligo dT beads (Invitrogen). cDNA was synthesized by using MMLV reverse transcriptase and oligo(dT) primers (MBI-add full name). SAGE libraries from 4 allotransplant and autotransplant groups were constructed following the standard procedure (13). For each SAGE library, 1,200 sequences were collected through an ABI 3730 DNA sequencer (Applied BioSystems). SAGE tags were extracted from the sequences by using the SAGE2000 software (Invitrogen).
Project description:This project aims to study two key points related to keratoplasty resistance. LSCs (limbal stem cells), which are crucial for the growth and repair of the cornea, have not been identified by specific markers. Furthermore, the characterization of corneal T/B cells has been rarely studied, even though they play a vital role in transplant rejection. To optimize donated corneas, researchers have utilized single-cell multi-omics methods such as single-cell 5’ mRNA and single-cell V(D)J sequencing to explore both LSCs and T/B immune repertoires (IR) simultaneously. Potential LSCs and dominant V(D)J types were analyzed, and the location of the cell marker was determined by RNA in situ sequencing. From the single-cell transcriptomics of 17,218 whole corneal cells, 20 cell subtypes were observed. A subcluster (0.3% of total cells) was identified as putative epithelial LSCs based on the known markers stating stem cells in the G0 cell cycle. TCR/BCR were rarely found in the cornea. The results suggest that GPHB5 could be a potential marker for limbal stem cells, but high-throughput single-cell VDJ sequencing is not the ideal method for analyzing corneal immune repertoires due to the rare presence of T/B cells.
Project description:Specific early diagnosis of renal allograft rejection is gaining importance in the current trend to minimize and individualize immunosuppression. Gene expression analyses could contribute significantly by defining “molecular Banff” signatures. Several previous studies have applied transcriptomics to distinguish different classes of kidney biopsies. However, the heterogeneity of microarray platforms, clinical samples and data analysis methods complicates the identification of robust signatures for the different types and grades of rejection. To address these issues, a comparative meta-analysis was performed across five different microarray datasets of heterogeneous sample collections from two published clinical datasets and three own datasets including biopsies for clinical indications, protocol biopsies, as well as comparative samples from non-human primates (NHP). This work identified conserved gene expression signatures that can differentiate groups with different histopathological findings in both human and NHP, regardless of the technical platform used. The marker panels comprise genes that clearly support the biological changes known to be involved in allograft rejection. A characteristic dynamic expression change of genes associated with immune and kidney functions was observed across samples with different grades of CAN. In addition, differences between human and NHP rejection were essentially limited to genes reflecting interstitial fibrosis progression. This data set here comprises a small validation batch of renal allograft biopsies for clinical indications plus control normal kidney samples from patients at Hôpital Tenon, Paris (second batch) that complements the first batch of 60 samples. We used microarrays to identify different gene expression signatures of renal allograft biopsies that can classify them according to different types of allograft rejection or CAN. Keywords: disease state analysis 4 renal allograft core biopsies for clinical indications with different histopathological diagnoses according to Banff'97 criteria and 2 normal kidney samples.