Single cell transcriptional profile of SC-islet grafts in an in vivo humanized model [scRNA-seq_invivo]

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 ? (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. Overall design: Comparing expression datasets from hPi grafts to controls