Project description:HLA-DR-lacking HSPCs [HLA-DR(-) HSPCs] were detected in aplastic anemia (AA) patients with HLA-DR15. HLA-DR(-) HSPCs may evade the attack by CD4+ T-cells recognizing the autoantigen presented by HLA-DR15. The goal of this study is to clarify the immune escape mechanisms from antigen-specific T-cells by comparing the trranscriptome profile of HLA-DR(+) HSPCs and HLA-DR(-) HSPCs.
Project description:Leprosy is a chronic granulomatous disease caused by infection with Mycobacterium leprae. Genetic association studies indicated that leprosy risk is strongly associated with variation within the major histocompatibility complex (MHC) region, but the full number of variants in this region has yet to be elucidated. To identify further susceptibility loci or loss of function variants for this disease, we performed fine-mapping analysis of the MHC region using a Han Chinese reference panel (n= 10,689 patients, 29,948 genetic markers) in the data sets from our previous leprosy studies. Then, a fixed-effect meta-analysis was carried out separately for Chinese (case=2,901, control=3,801) and North Chinese (case=1,983, control=2,635) participants. The meta-analysis of Chinese participants identified 10 HLA-type or amino acid variants with lower than the genome-wide significant susceptibility signal. Next, gene-by-gene step-wise conditional analysis was performed in the combined dataset of these cohorts. Finally, we identified four new independent susceptibility loci (HLA-DQA1, HLA-C, rs3129063, and rs58327373) and confirmed one previously reported locus (HLA-DRB1) that significantly associated with leprosy in the Chinese Han population. Thus the results of this study increase knowledge about leprosy risk variants and illustrate the value of HLA imputation for fine mapping of causal variants in the MHC.
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:Few non-classical HLA-E restricted HIV-specific epitopes have been described, and even less is known about the functional profile of responding CD8 T cells (CD8s). This study evaluates the functional characteristics of CD8s targeting the Gag epitope (KAFSPEVIPMF or KF11) based on their restriction by either HLA-E (E-CD8s) or HLA-B57 (B57-CD8s). CD8s from 8 people with HIV (PWH) were cocultured with KF11 peptide presented by cell lines expressing HLA-B*57:01, HLA-E*01:01 or E*01:03. CD8s were analyzed through single-cell (sc) RNA and TCR sequencing. Additionally, supernatants were analyzed for soluble proteomics using a Luminex assay. B57-CD8s secreted higher levels of cytotoxic cytokines such as IFNγ, while E-CD8s produced more chemotactic cytokines, including RANTES, CXCL10 (IP-10), and IL27confirmed through scRNAseq. Despite distinct cytokine profiles, TCR clonotypes stimulated by KF11 were cross-restricted by HLA-B*57 and HLA-E*01/03. In vitro T cell reporter assays clearly demonstrated this cross-restriction. A TRAV5-containing metaclonotype cluster was seen in PWH with lower viral loads. These findings demonstrate that HIV-specific CD8s in PWH exhibit cross HLA-B*57 and HLA-E*01/03 restriction, resulting in functionally distinct immune responses that may contribute to HIV control.
Project description:Few non-classical HLA-E restricted HIV-specific epitopes have been described, and even less is known about the functional profile of responding CD8 T cells (CD8s). This study evaluates the functional characteristics of CD8s targeting the Gag epitope (KAFSPEVIPMF or KF11) based on their restriction by either HLA-E (E-CD8s) or HLA-B57 (B57-CD8s). CD8s from 8 people with HIV (PWH) were cocultured with KF11 peptide presented by cell lines expressing HLA-B*57:01, HLA-E*01:01 or E*01:03. CD8s were analyzed through single-cell (sc) RNA and TCR sequencing. Additionally, supernatants were analyzed for soluble proteomics using a Luminex assay. B57-CD8s secreted higher levels of cytotoxic cytokines such as IFNγ, while E-CD8s produced more chemotactic cytokines, including RANTES, CXCL10 (IP-10), and IL27confirmed through scRNAseq. Despite distinct cytokine profiles, TCR clonotypes stimulated by KF11 were cross-restricted by HLA-B*57 and HLA-E*01/03. In vitro T cell reporter assays clearly demonstrated this cross-restriction. A TRAV5-containing metaclonotype cluster was seen in PWH with lower viral loads. These findings demonstrate that HIV-specific CD8s in PWH exhibit cross HLA-B*57 and HLA-E*01/03 restriction, resulting in functionally distinct immune responses that may contribute to HIV control.