Project description:A whole genome screen using a CRISPR lentivirus library (Doench et al., 2016) was performed. The Brunello CRISPR library consists of a pool of 76,441 human targeting guide RNAs (gRNA) and 1000 control gRNAs [non-targeting (NT) or intergenic], in a lentiviral vector that expresses Cas9. The pooled library targets 19,114 human genes, most of them by four gRNA per gene. To avoid multiple different gRNA in cells and a nonspecific effect on the screen results (Doench, 2018), a low infection lentivirus titer (multiplicity of infection that is <1) was used. Library transduced cells (LT SC-islets) were allowed at least 10 days for CRISPR editing, before transplantation to the NSG-MHCnull mouse model, where PBMCs were injected to half of the cohort (hPi mice: n=6, control mice: n=6) (Figures 3A). hPi mice retained levels of circulating T cells throughout the experiment (Figures S3A and S3B). Graft function and subsequent failure due to human PBMC injection was assessed (Figures 3B and S3C). When hPi graft failure was confirmed, 10 weeks after PBMC injection (Figure 3B), both control and hPi grafts were recovered from kidney sites, genomic DNA (gDNA) was extracted, and gRNA regions were amplified by PCR for Illumina sequencing.
Project description:we present the first comprehensive analysis of the heterogeneity in gene expression and cell types in the allogeneic and syngeneic mouse heart grafts using scRNA-seq. We identify 21 distinct cell populations by performing dimensionality reduction and unsupervised cell clustering analysis in the allogeneic and syngeneic heart grafts.
Project description:To study immune responses in the context of human allogeneic graft rejection, we chose the Hu-PBL-NSG-MHCnull humanized mouse (Brehm et al., 2019). NOD-scid IL-2 receptor subunit γ (IL2rg)null (NSG) immunocompromised mice that lack murine MHC class I and II, were transplanted (under the kidney capsule, n=12) with 5M SC-islets (HLA-A2 positive), followed by human PBMC injection (termed ‘hPi-mice’; 50M/mouse, n=6) from healthy unmatched donors (HLA-A2 negative). The lack of murine MHC allowed us to monitor the graft function for prolonged durations without the risk of xenogeneic graft vs host disease (GVHD). Half of the SC-islet transplanted cohort (n=6 mice) was used as the control, without PBMC injection (Figure 1A). Since graft elimination by PBMCs is incomplete and residual endocrine cells remain in the hPi-mice grafts, we retrieved the SC-islet grafts for single cell RNA sequencing (scRNA-seq) analysis. These samples, along with pre-injected PBMCs as controls, were used for 10x Genomics mRNA expression library preparation and Illumina sequencing.
Project description:Allogeneic chimeric antigen receptor (CAR)-T cell therapies hold the potential to overcome many of the challenges associated with patient-derived (autologous) CAR-T cells. Key considerations in the development of allogeneic CAR-T cell therapies include prevention of GvHD and suppression of allograft rejection. Here we describe preclinical data supporting the ongoing first-in-human clinical trial (CaMMouflage) in relapsed/refractory multiple myeloma patients evaluating CB-011, a hypoimmunogenic, allogeneic anti–B cell maturation antigen (BCMA) CAR-T cell therapy candidate. CB-011 cells feature 4 genomic alterations and were engineered from healthy donor-derived T cells using a Cas12a CRISPR hybrid RNA-DNA (chRDNA) genome-editing technology platform. To address allograft rejection, CAR-T cells were engineered to prevent endogenous human leukocyte antigen (HLA) class I complex expression and overexpress a single-chain polyprotein complex composed of beta-2 microglobulin (B2M) tethered to HLA-E. Additionally, T cell receptor expression was disrupted at the T cell receptor alpha constant locus in combination with the site-specific insertion of a humanized BCMA-specific CAR. CB-011 cells exhibited robust plasmablast cytotoxicity in vitro in a mixed lymphocyte reaction in cell co-cultures derived from patients with multiple myeloma. Additionally, CB-011 cells demonstrated suppressed recognition by and cytotoxicity from HLA-mismatched T cells. CB-011 cells were protected from natural killer (NK) cell–mediated cytotoxicity in vitro and in vivo due to endogenous promoter-driven expression of B2M–HLA-E. Potent antitumor efficacy, when combined with an immune-cloaking armoring strategy to dampen allograft rejection, offers optimized therapeutic potential in multiple myeloma.
Project description:A promise of cell replacement therapy using pluripotent stem cells (PSCs) such as embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) as donor source has been increased. However, particularly when ESCs were used, immune suppression should be required because the donor-recipient combination would be allogeneic. In this study, we examined a concept that some immunosuppressive cells could be induced from PSCs and those cells could prevent allogeneic immune rejection of the PSCs-based transplantation. In fact, we successfully induced immunosuppressive cells that resemble M2 macrophages in terms of cell surface molecule and gene expressions. They efficiently suppressed allogeneic T cell proliferative responses, at least partly, in nitric oxide dependent manner. We applied these cells to in vivoallogeneic transplantation and found that they substantially prolonged ESCs-derived graft survival. These results open a new insight for development of a practical immune-regulatory strategy in cell replacement therapy using PSCs. Difference of the gene expression between ESdSC and ESdDC was analyzed. Two independent experiment were performed.
Project description:MicroRNAs are small non-coding RNA molecules that regulate the post-transcriptional expression of target genes. In addition to being involved in many biologic processes including development, cell differentiation, proliferation, and apoptosis, microRNAs are important regulators in innate and adaptive immune responses. Distinct sets of expressed miRNAs are found in different cell types and tissues and aberrant expression of microRNAs is associated with many disease states. MicroRNA expression was examined in a model of heterotopic heart transplantation by microarray analyses and a unique profile was detected in rejecting allogeneic transplants (BALB/C to C57BL/6) as compared to syngeneic transplants (C57BL/6 to C57BL/6). The microRNA miR-182 was significantly increased in rejecting cardiac allografts and in mononuclear cells that infiltrate the grafts. Forkhead Box (FOX) proteins are a family of important transcription factors and FOXO1 is a target of miR-182. As miR-182 increases after transplant, there is a concomitant post-transcriptional decrease in FOXO1 expression in heart allografts that is localized to both the cardiomyocytes and CD3+ T cells. The microRNA miR-182 is significantly increased in both PBMC and plasma during graft rejection suggesting potential as a biomarker of graft status. Our results identify microRNAs that may regulate alloimmune responses and graft outcomes. In total 14 microRNA microarrays data. For heart graft: each sample column corresponds to the expression profile of 3 pooled syngeneic or 3 pooled allogeneic heart grafts or 3 pooled normal heart. For graft infiltrating lymphocytes (GILs): each sample column corresponds to the expression profile of 3 pooled syngeneic or 3 pooled allogeneic GILs or 3 pooled normal PBMC.
Project description:A promise of cell replacement therapy using pluripotent stem cells (PSCs) such as embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) as donor source has been increased. However, particularly when ESCs were used, immune suppression should be required because the donor-recipient combination would be allogeneic. In this study, we examined a concept that some immunosuppressive cells could be induced from PSCs and those cells could prevent allogeneic immune rejection of the PSCs-based transplantation. In fact, we successfully induced immunosuppressive cells that resemble M2 macrophages in terms of cell surface molecule and gene expressions. They efficiently suppressed allogeneic T cell proliferative responses, at least partly, in nitric oxide dependent manner. We applied these cells to in vivoallogeneic transplantation and found that they substantially prolonged ESCs-derived graft survival. These results open a new insight for development of a practical immune-regulatory strategy in cell replacement therapy using PSCs.
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.