Project description:We conducted immune- and RNA-sequencing of HLA-A24-restricted CMVpp65-specific CTLs to better understand the immune reconstitution of CMV-CTLs after allo-HCT. To the best of our knowledge, this is the first report on the features of TCRβ-CDR3, diversity, and GEP of HLA-A24 CMV-CTLs according to the CMV-reactivation pattern among recipients after allo-HCT. In addition, we further sought to demonstrate homogeneity or heterogeneity according to individual CTL clones using single-cell RNA-sequencing technology.
Project description:We conducted immune- and RNA-sequencing of HLA-A24-restricted CMVpp65-specific CTLs to better understand the immune reconstitution of CMV-CTLs after allo-HCT. To the best of our knowledge, this is the first report on the features of TCRβ-CDR3, diversity, and GEP of HLA-A24 CMV-CTLs according to the CMV-reactivation pattern among recipients after allo-HCT. In addition, we further sought to demonstrate homogeneity or heterogeneity according to individual CTL clones using single-cell RNA-sequencing technology.
Project description:Longitudinal Study of Immune Mediated Disorders after Allogeneic HCT Protocol (Immune Mediated Disorders after Allo-HCT) - cGVHD 6501
Project description:Bach2 codes for a transcriptional regulator exerting major influences on T cell mediated immune regulation. Effector CTLs derived from in vitro activation of murine CD8+ T cells showed increased proliferative and cytolytic capacity in the absence of BACH2. Before activation, BACH2-deficient CD8+ T cells had a higher abundance of memory and reduced abundance of naïve cells compared to wild-type. CTLs derived from central memory T cells were more potently cytotoxic than those derived from naïve T cells, but even within separated subsets, BACH2-deficiency conferred a cytotoxic advantage. Immunofluorescence and electron microscopy revealed larger granules in BACH2-deficient compared to wild-type CTLs, and proteomic analysis showed an increase in granule content, including perforin and granzymes. Thus, the enhanced cytotoxicity observed in effector CTLs lacking BACH2 arises not only from differences in their initial differentiation state but also inherent production of enlarged cytolytic granules. These results demonstrate how a single gene deletion can produce a CTL super-killer.
Project description:Acquisition of effector properties is a key step in the generation of cytotoxic T lymphocytes (CTLs). Here we show that inflammatory signals regulate Dicer expression in CTL, and that deletion or depletion of Dicer in mouse or human activated CD8+ T cells causes upregulation of perforin, granzyme and effector cytokines. Genome-wide analysis of miRNA changes induced by exposure of differentiating CTLs to IL-2 and inflammatory signals identifies miR-139 and miR-150 as components of a miRNA network that controls perforin, eomesodermin (Eomes) and IL-2Ra expression in differentiating CTLs and whose activity is modulated by IL-2, inflammation and antigenic stimulation. Overall our data show that strong IL-2R and inflammatory signals act through Dicer and miRNAs to control the cytolytic program and other aspects of effector CTL differentiation. Comparison of control and Dicer knock-out CTLs differentiated in vitro; Comparison of wild type CTLs differentiated in vitro with or without inflammatory stimuli; Comparison of effector and memory precursor CTLs isolated from mice infected with LCMV-Armstrong
Project description:The latent human Cytomegalovirus (hCMV) infection can pose a serious threat of reactivation and disease occurrence in immune-compromised individuals, as well as burdens the immune system in immune-competent individuals. Though, T cells are at the core of the protective immune response to hCMV infection, a detailed characterization of different T cell subsets involved in protection against the hCMV infection is lacking. Here we analyzed the single-cell transcriptomes and the single-cell T cell antigen receptor (TCR) repertoires of over 8000 hCMV-reactive peripheral T cells isolated from different memory compartments. The hCMV-reactive T cells were highly heterogeneous and consisted of different developmental memory and functional T cell subsets such as, the long-term memory precursors and effectors, T helper-17, T regulatory cells (TREGs) and cytotoxic T lymphocytes (CTLs). The hCMV-antigen specific TREGs were enriched for molecules linked to their suppressive function and interferon response genes. The CTLs were of two types, the pre-effector and effector like. Of particular interest was the mixture of both CD4-CTLs and CD8-CTLs in both the pre-effector and effector cytotoxic clusters, suggesting that both CD4-CTLs and CD8-CTLs share transcriptomic signatures. The huge TCR clonal expansion of both the cytotoxic clusters imply their predominant role in protective immune response to CMV. Further the clonotype sharing between the CTL clusters and the long-term memory clusters, indicate potential progenitors of CD4-CTLs. Together our study has identified many subsets of hCMV-specific memory T cells that may have implication in better understanding the hCMV-specific T cell immunity to design vaccination strategies and therapeutics.
Project description:Celiac disease is an intestinal inflammatory disorder induced by dietary gluten in genetically susceptible individuals. The mechanisms underlying the massive expansion of interferon g–producing intraepithelial cytotoxic T lymphocytes (CTLs) and the destruction of the epithelial cells lining the small intestine of celiac patients have remained elusive. We report massive oligoclonal expansions of intraepithelial CTLs that exhibit a profound genetic reprogramming of natural killer (NK) functions. These CTLs aberrantly expressed cytolytic NK lineage receptors, such as NKG2C, NKp44, and NKp46, which associate with adaptor molecules bearing immunoreceptor tyrosine-based activation motifs and induce ZAP-70 phosphorylation, cytokine secretion, and proliferation independently of T cell receptor signaling. This NK transformation of CTLs may underlie both the self-perpetuating, gluten-independent tissue damage and the uncontrolled CTL expansion leading to malignant lymphomas in severe forms of celiac disease. Because similar changes were detected in a subset of CTLs from cytomegalovirus-seropositive patients, we suggest that a stepwise transformation of CTLs into NK-like cells may underlie immunopathology in various chronic infectious and inflammatory diseases. Keywords: NKG2C; LAK; CTL; NK receptor; IEL; Mucosal Immunity; Celiac Disease
Project description:The present study reports an unbiased analysis of the cytotoxic T cell serine-threonine phosphoproteome using high resolution mass spectrometry. Approximately 2,000 phosphorylations were identified in CTLs of which approximately 450 were controlled by TCR signaling. A significantly overrepresented group of molecules identified in the phosphoproteomic screen were transcription activators, co-repressors and chromatin regulators. A focus on the chromatin regulators revealed that CTLs have high expression of the histone deacetylase HDAC7 but continually phosphorylate and export this transcriptional repressor from the nucleus. HDAC7 dephosphorylation results in its nuclear accumulation and suppressed expression of genes encoding key cytokines, cytokine receptors and adhesion molecules that determine CTL function. The screening of the CTL phosphoproteome thus reveals intrinsic pathways of serine-threonine phosphorylation that target chromatin regulators in CTLs and determine the CTL functional program. We used Affymetrix microarray analysis to explore the molecular basis for the role of HDAC7 in CTLs and the impact of GFP-HDAC7 phosphorylation deficient mutant expression on the CTL transcriptional profile. In vitro generated P14 TCR cytotoxic T cells were retrovirally infected with a construct encoding GFP-HDAC7 phosphorylation deficient mutant, sorted in base of GFP expression (GFP positive and GFP negative) and processed for microarray analysis in three biological replicas.