Project description:Myeloid-derived suppressor cells (MDSC) is a heterogeneous population of cells that can negatively regulate T-cell function. As opposed to murine MDSC, which are characterized as Gr-1+CD11b+ cells, human MDSC are not so clearly defined due to lack of specific markers. Our lab has previously identified a new subset of MDSC as CD14+HLA-DR-neg/low cells from PBMC. CD14+HLA-DR-neg/low MDSC not only suppress proliferation and IFN-gamma secretion of autologous T cells, but also induce CD25+Foxp3+ regulatory T cells that are suppressive in vitro, whereas the counterpart CD14+HLA-DR-high monocytes don’t have the effect. In this study, we compare the immune-related gene expression between CD14+HLA-DR-neg/low MDSC and CD14+HLA-DR-high monocytes to better characterize the difference between these two populations and to find new potential specific marker for human MDSC. PBMC were isolated from fresh blood healthy donor by density centrifugation. CD14+ cells were isolated by AutoMACS CD14 microbeads using a AutoMACS (Miltenyi), and then stained with CD14 and HLA-DR antibodies. MDSC and monocytes control cells were sorted as CD14+ HLA-DR-neg/low and CD14+HLA-DR-high cells respectively. The sorted two populations were immediately frozen in liquid nitrogen and shipped to the company on dry ice for RNA isolation and further microarray.
Project description:Human cytomegalovirus infection (CMV) can stimulate robust human leukocyte antigen (HLA)-E restricted CD8 T cell responses. These T cells recognize a peptide from UL40, which differs by as little as a single methyl group from self-peptides that also bind HLA-E, challenging their capacity to avoid self-reactivity. We showed in one donor 2 distinct populations of UL40/HLA-E T cells, with vastly different T cell receptor (TCR) affinities for the UL40/HLA-E complex. However, paradoxically, lower cytokine responses were observed from UL40/HLA-E T cells bearing TCRs with high affinity for HLA-E. To identify why these T cells bearing high affinity T cell receptors were less responsive to antigens, we performed single cell RNAseq analysis. These 2 distinct populations of T cells were single-cell sorted into 96-well plates prior to single cell RNA-seq analysis.
Project description:We interrogated the transcriptome from bulk-sorted T1D donor β-cells as compared to non-diabetic donors. We found β-cells also expressed mRNA for HLA Class II and Class II antigen presentation pathway components, but not a macrophage marker.
Project description:HLA-E molecules can present self and pathogen-derived peptides to both NK-cells and T-cells. T-cells that recognize HLA-E peptides via their T-cell receptor (TCR) are termed donor-unrestricted T-cells due to restricted allelic variation of HLA-E. The composition and repertoire of HLA-E TCRs is not known so far. We performed TCR sequencing on CD8+ T-cells from 21 individuals recognizing HLA-E tetramers (TM) folded with 2 Mtb HLA-E restricted peptides. We sorted HLA-E Mtb TM+ and TMCD8+ T-cells directly ex vivo and performed bulk RNA-sequencing and single cell TCR sequencing. The identified TCR repertoire was diverse and showed no conservation between and within individuals. TCRs selected from our single cell TCR sequencing data could be activated upon HLA-E/peptide stimulation, although not robust, reflecting potentially weak interactions between HLA-E peptide complexes and TCRs. Thus, HLA-E Mtb specific T-cells have a highly diverse TCR repertoire.
Project description:We constructed a clinical-grade haplobank of 27 induced pluripotent stem cells (iPSCs) lines prepared in accordance with good manufacturing practice regulations from seven donors who were homozygous for one of the four most frequent human leukocyte antigen (HLA)-haplotypes in Japan. The haplobank could provide HLA-matched iPSCs lines to ~40% of the Japanese population. Since the first release in 2015, these iPSC lines have been used in more than 12 clinical studies. We performed rigorous quality control (QC) tests, including residual episomal vectors, genetic mutations in cancer-related genes, copy number alterations, karyotype, expression of markers of the undifferentiated state, morphology, identity (HLA typing and short tandem repeat analysis), sterility and endotoxin. Although the significance of most mutations in cancer-related genes is unknown, we excluded iPSC lines with such mutations to maximize the safety. The haplobank we have established here is an important step toward the clinical application of iPSCs in cell therapies.