Project description:Disruption of TCR /MHC class II interactions leads rapidly to alterations of the common CD4 Treg transcriptional signature Self-deprived, non-functional Tregs were compare to fully functional Tregs by microarrays. Total T cells from the periphery of WT mice were adoptively transferred into CD3ε-/- recipient mice lacking or not MHC class II molecule expression (MHC II- or MHC II+ recipient mice, respectively). Five days later, peripheral Tregs transferred in MHC II - competent (CD4CD25B6) or - deficient (CD4CD25IIko) recipient were purified for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma and infections remain a substantial global health problem for which no curative therapy exists. As cytotoxic CD8+ T lymphocytes are the principal effectors of natural HBV resolution, there is considerable interest in discovering novel HBV epitopes that are presented for immune recognition. Current knowledge of HBV-derived peptide presentation to CD8+ T cells is largely dominated human leukocyte antigen (HLA)-A*02:01. Our aim was to characterise novel HBV-derived peptides presented on HLA-B and -C molecules, particularly allotypes that are prevalent in regions with high HBV infection rates. Additionally, we sought to determine if the recently discovered major histocompatibility complex class I (MHC-I) peptide editor TAPBPR modulated expression of HBV-derived epitopes. To discover new HBV-derived epitopes, immunopeptidomic analysis was performed on cells expressing single HLA class I molecules transduced to express individual HBV proteins. Peptide binding assays were used to validate HLA binding of selected peptides. To determine the effect of TAPBPR on the HBV peptidome, immunopeptidomic analysis was performed on either wild-type HeLa cells expressing HBV proteins or their TAPBPRKO counterpart. The results were validated using TAPBPR peptide-exchange assays. We identified 28 novel HBV-derived peptides presented on HLA class I. Importantly, 22 of the newly discovered HBV-derived peptides were identified on cells expressing HLA-B*08:01, -B*15:03, -B*35:01, -C*06:02 and -C*12:03. Additionally, TAPBPRKO HeLa cells presented four additional and novel HBV-derived peptides. This work presents a substantial expansion of the HLA-B and HLA-C-restricted HBV-derived peptides described in the Immune Epitope Database (IEDB). Additionally, this work represents the first indication that TAPBPR shapes not only the cellular but also the viral peptide repertoire presented on MHC-I molecules.
Project description:Comparison of peptide ligands of major histocompatibility class (MHC) I isolated by immunoaffinity purification from the C1R (Class I reduced) B-lymphoblastoid cell line, transfected with the MHC class I alleles HLA-B*57:01, HLA-B*57:03 and HLA-B*58:01.
Project description:Over expression of MHC Class l protein in skeletal muscle causes myositis. Phenotype after expression in young mice is more severe. We performed gene expression profiling on young and adult mice after over expression of self MHC class l protein in skeletal muscle Muscle from young ( early) , adult (Late) and cntrol (control) mice , n=3 each group, was used for gene expression profiling
Project description:Over expression of MHC Class l protein in skeletal muscle causes myositis. Phenotype after expression in young mice is more severe. We performed gene expression profiling on young and adult mice after over expression of self MHC class l protein in skeletal muscle
Project description:The T cell response to Chlamydia genital tract infections in humans and mice is unusual in that the majority of antigen-specific CD8 T cells are not restricted by HLA/MHC class I and therefore have been referred to as “unrestricted” or “atypical”. We previously reported that a subset of unrestricted murine Chlamydia-specific CD8 T cells had an unusual cytokine polarization pattern that included IFN-ɣ and IL-13. For this report, we investigated the transcriptome of Chlamydia-specific CD8ɣ13 T cells, comparing them to Chlamydia-specific multifunctional Tc1 clones using gene expression micro array analysis. The molecular study revealed that CD8ɣ13 polarization included IL-5 in addition to IFN-γ and IL-13. Adoptive transfer studies were performed with Tc1 clone and CD8ɣ13 T cell clones to determine whether either influenced bacterial clearance or immunopathology during Chlamydia muridarum (Cm) genital tract infections. To our surprise, an adoptively transferred CD8ɣ13 T cell clone was remarkably proficient at preventing chlamydia immunopathology while the multifunctional Tc1 clone did not enhance clearance or significantly protect from immunopathology. Mapping studies with MHC class I- and class II-deficient splenocytes showed our previously published Chlamydia-specific CD8 T cell clones are MHC class II-restricted. MHC class II-restricted CD8 T cells may play important roles in protection from intracellular pathogens that limit class I antigen presentation or deplete the CD4 T cell compartment.
Project description:Genome wide association studies of schizophrenia encompassing the major histocompatibility locus (MHC) were highly significant following genome wide correction. This broad region implicates many genes including the MHC complex class II. Within this interval we examined the expression of two MHC II genes (HLA-DPA1 and HLA-DRB1) in brain from individual subjects with schizophrenia (SZ), bipolar disorder (BD), major depressive disorder (MDD), and controls by differential gene expression methods. A third MHC II mRNA, CD74, was studied outside of the MHC II locus, as it interacts within the same immune complex. HLA-DPA1 and CD74 were both reduced in hippocampus, amygdala, and dorsolateral prefrontal cortex regions in SZ and BD compared to controls by specific qPCR assay. We found several novel HLA-DPA1 mRNA variants spanning HLA-DPA1 exons 2-3-4 as suggested by an exon microarray study. The intronic rs9277341 SNP was a significant cis expression quantitative trait locus (eQTL) that was associated with the total expression of HLA-DPA1 in five brain regions. A biomarker study of MHC II mRNAs was conducted in SZ, BD, MDD, and control lymphoblastic cell lines (LCL) by qPCR assay of 87 subjects. There was significantly decreased expression of HLA-DPA1 and CD74 in BD, and trends for reductions in SZ in LCLs. The discovery of multiple splicing variants in brain for HLA-DPA1 is important as the HLA-DPA1 gene is highly conserved, there are no reported splicing variants, and the functions in brain are unknown. Future work on the function and localization of MHC Class II proteins in brain will help to understand the role of alterations in neuropsychiatric disorders. The HLA-DPA1 eQTL is located within a large linkage disequilibrium block that has an irrefutable association with schizophrenia. Future tests in a larger cohort are needed to determine the significance of this eQTL association with schizophrenia. Our findings support the long held hypothesis that alterations in immune function are associated with the pathophysiology of psychiatric disorders. There were 20 anterior cingulate postmortem brain samples that were extracted for total RNA, and analyzed using Affymetrix Exon Array (bipolar disorder subjects n = 9, controls n = 11).
Project description:The transcription factor HELIOS is primarily known for its expression in CD4 regulatory T cells. In mice, HELIOS is also found in exhausted CD8 T cells. However, information on human HELIOS+ CD8 T cells is limited and conflicting. In this study, we characterized human HELIOS+ CD8 T cells, and found that these cells comprise approximately 21% of blood CD8 T cells. The majority of HELIOS+ CD8 T cells are memory cells, and some of them recognize peptides presented by the MHC class Ib molecule HLA-E. Memory HELIOS- T-BEThigh CD8 T cells displayed robust effector functions, while HELIOS+ T-BEThigh CD8 T cells produce low amounts of IFN- and TNF- and have a lower cytotoxic potential. Additionally, a portion of HELIOS+ CD8 T cells express TH17/TC17-related genes RORt, ROR, PLZF, CD161 and CCL20. Thus, HELIOS is expressed in various CD8 T cell populations, including T-BEThigh cells with lower effector functions, and TC17 cells. It remains to be understood why so many individuals maintain in their blood high amounts of HELIOS+ T-BEThigh CD8 T cells that produce low amounts of cytokines upon activation and what the connection between HELIOS and HLA-E restriction means.