Project description:We tested the hypothesis that single-cell RNA-sequencing (scRNA-seq, 10X) and computational analysis of human kidney allograft biopsies will reveal new cell types and cell states and yield insights to personalize the care of transplant recipients.
Project description:We report the first use of genome-edited human kidney organoids, combined with single-cell transcriptomics, to study APOL1 risk variants at the native genomic locus in different nephron cell types. This approach captures interferon-mediated induction of APOL1 gene expression and cellular dedifferentiation with a secondary insult“second hit” of endoplasmic reticulum stress.
Project description:The aim of this study was to investigate correlations between early subclinical findings (10 and 90 day histology and gene expression data) and late outcomes (transplant glomerulopathy and graft loss) in positive crossmatch kidney transplants (+XMKTx). Our goal was threefold: first, to confirm that intragraft molecular changes at 12m post-transplant are associated with the observed histologic changes in SLK transplant recipients, compared with KTA transplant recipients; second, to ascertain whether specific molecular pathways/markers that are not accounted for by routine histology are differentially expressed in the kidney allografts of the SLK transplant recipients; and third, to determine whether a molecular signature that is uniquely associated with simultaneous liver transplantation can be identified in kidney allografts.
Project description:The aim of this study was to investigate correlations between early subclinical findings (10 and 90 day histology and gene expression data) and late outcomes (transplant glomerulopathy and graft loss) in positive crossmatch kidney transplants (+XMKTx). Our goal was threefold: first, to confirm that intragraft molecular changes at 12m post-transplant are associated with the observed histologic changes in SLK transplant recipients, compared with KTA transplant recipients; second, to ascertain whether specific molecular pathways/markers that are not accounted for by routine histology are differentially expressed in the kidney allografts of the SLK transplant recipients; and third, to determine whether a molecular signature that is uniquely associated with simultaneous liver transplantation can be identified in kidney allografts. Biopsy samples were from positive and negative crossmatch simultaneous liver-kidney transplant recipients (12 month protocol biopsies) were compared to control patient (positive and negative crossmatch) biopsies obtained at 12 months. This dataset is part of the TransQST collection.
Project description:Follicular helper T (Tfh) cells have been implicated in controlling rejection after allogeneic kidney transplantation, but the precise subsets, origins and functions of Tfh cells in this process have not been fully characterized. Here we show that a subset of effector Tfh cell marked by previous IL- 21 production is potently induced during allogeneic kidney transplantation and is inhibited by immunosuppressive agents. Single-cell RNAseq revealed that these lymph node effector Tfh cells have transcriptional and clonal overlap with IL-21 producing kidney infiltrating Tfh cells, implicating common origins and developmental trajectories. To investigate the precise functions of IL-21 producing effector Tfh cells in lymph nodes and allografts, we used a mouse model to selectively eliminate these cells and assessed allogeneic B cell clonal dynamics using a single B cell culture system. We found that IL-21 producing effector Tfh cells were essential for transplant rejection by regulating donor-specific germinal center B cell clonal dynamics both systemically in the draining lymph node and locally within kidney grafts. Thus, IL-21 producing effector Tfh cells have multifaceted roles in antibody-mediated rejection after kidney transplantation by promoting B cell alloimmunity.
Project description:Purpose: Chronic allograft dysfunction (CAD) remains a major obstacle in kidney transplantation. However, the molecular pathogenesis of human CAD is unknown. Herein, we tested the hypothesis that single nuclei transcriptomics of human kidney allograft fibrosis will reveal diverse cell types, deconvolve complex fibrosis-driving pathways, and provide deeper insights into the progression of kidney allograft dysfunction.
Project description:We used a murine kidney transplantation model and single-cell transcriptomics to dissect the contribution of myeloid cell subsets and their potential signaling pathways to kidney transplant rejection. Using a variety of bioinformatic techniques including machine learning, we demonstrated that kidney allograft-infiltrating myeloid cells followed a trajectory of differentiating from monocytes to pro-inflammatory macrophages, and exhibited distinct interactions with kidney allograft parenchymal cells. While this process correlated with a unique pattern of myeloid cell transcripts, a top gene identified was Axl, a member of the receptor tyrosine kinase familyTAM(Tyro3/Axl/Mertk).