Project description:Rapid advances in biochemical technologies have enabled several strategies for typing candidate HLA alleles, but linking them into a single MHC haplotype structure remains challenging. Here we have developed a multi-loci haplotype phasing technique and demonstrate its utility towards phasing of MHC and KIR loci in human samples. We accurately (~99%) reconstruct the complete haplotypes for over 90% of sequence variants spanning the 4-megabase region of these two loci. By haplotyping a majority of coding and non-coding alleles at the MHC and KIR loci in a single assay, this method has the potential to assist transplantation matching and facilitate investigation of the genetic basis of human immunity and disease. Complete haplotype phasing of 2 loci (MHC and KIR) in 1 human cell line.
Project description:Rapid advances in biochemical technologies have enabled several strategies for typing candidate HLA alleles, but linking them into a single MHC haplotype structure remains challenging. Here we have developed a multi-loci haplotype phasing technique and demonstrate its utility towards phasing of MHC and KIR loci in human samples. We accurately (~99%) reconstruct the complete haplotypes for over 90% of sequence variants spanning the 4-megabase region of these two loci. By haplotyping a majority of coding and non-coding alleles at the MHC and KIR loci in a single assay, this method has the potential to assist transplantation matching and facilitate investigation of the genetic basis of human immunity and disease.
Project description:Uterine NK cells (uNK cells) form a distinct immune cell population in the endometrium and decidua. Here, we FACS-sorted KIR-CD39-,KIR+CD39- and KIR+CD39+ uNK cells from decidual samples.
Project description:Previous reports show that Ly49+CD8+ T cells can suppress autoimmunity in mouse models of autoimmune diseases. Here we find a markedly increased frequency of CD8+ T cells expressing inhibitory Killer cell Immunoglobulin like Receptors (KIR), the human equivalents of the Ly49 family, in the blood and inflamed tissues of various human autoimmune diseases. Moreover, KIR+CD8+ T cells can efficiently eliminate pathogenic gliadin-specific CD4+ T cells from Celiac disease (CeD) patients’ leukocytes in vitro. Furthermore, we observe elevated levels of KIR+CD8+ T cells, but not CD4+ regulatory T cells, in COVID-19 and influenza-infected patients, and correlate with disease severity and vasculitis in COVID-19. Expanded KIR+CD8+ T cells from these different diseases display shared phenotypes and similar T cell receptor sequences. These results characterize a regulatory CD8+ T cell subset in humans, broadly active in both autoimmune and infectious diseases, which we hypothesize functions to control self-reactive or otherwise pathogenic T cells.
Project description:AIM: To investigate the adaptive properties of NK cells, by comparing the expression profiles of FACS-sorted KIR+ (CD158b1b2j) and KIR- NK cells from patients experiencing or not a Cytomegalovirus (HCMV) reactivation after haploidentical hematopoietic stem cell transplantation (h-HSCT). RESULTS: Our flow cytometry data demonstrate that KIR+ NK cells are expanded in h-HSCT patients upon HCMV reactivation, thus suggesting that these cells could be important in controlling the viral infection and could be endowed with adaptive features. By comparing the expression profiles of KIR+ and KIR- NK cells from reacivated patients, we demonstrated a cytokine receptor unbalance, a prevalence of pathways associated to mitochondrial respiration and consequent ATP synthesis, a downregulation of genes involved in epigenetic reprogramming, all properties attributable adaptive NK cells. By comparing the molecular fingerprint of KIR+ NK cells between patients experiencing a HCMV reactivation and not reactivated patients, we observed in reactivated group an upregulation of INFG expression and in genes involved in Signaling receptor activity and MHC class II antigen presentation , thus strengthens the hypothesis that our KIR+ NK cells in reactevated h-HSCT patients are able to produce IFN-γ driving specific responses upon re-stimulation. However, the enrichment in PD-1 signaling, let us speculate that KIR+ NK cells from reactivated h-HSCT patients have impaired effector-functions.
Project description:During pregnancy, immune responses must balance fetal protection from infections with tolerance of the semi-allogeneic fetus. However, the mechanisms regulating maternal-fetal tolerance remain poorly understood. Recently, we identified KIR+CD8+ T cells as a previously underappreciated regulatory subset important for suppressing self-reactivity in human autoimmune and infectious diseases. To better understand what other roles these cells might play, we asked whether they are active during pregnancy. We first observed an increased frequency of KIR+CD8+ T cells in the peripheral blood of pregnant women at the second trimester, especially in those carrying a male fetus. In vitro, KIR+CD8+ T cells inhibited the alloreactive responses of maternal T cells against irradiated cord blood cells and suppressed HY-specific CD8+ T cells from mothers with a male fetus. Therefore, the higher induction of KIR+CD8+ T cells in mothers carrying a male fetus may help suppress additional allogenic responses triggered by Y chromosome antigens. Longitudinal analysis showed that KIR+CD8+ T cells undergo expansion and differentiate into functional cytotoxic cells during pregnancy. Single cell RNA-seq analysis of decidual CD8+ T cells from early pregnancy revealed elevated number and activity of KIR+ CD8+ T cells at the maternal-fetal interface. In addition, increased levels of KIR+CD8+ T cells correlated with pregnancy disorders (e.g., spontaneous abortion and preeclampsia). Taken together, our findings suggest an important role of KIR+CD8+ T cells in the maintenance of maternal tolerance by suppressing fetal-specific alloreactive T cells. They may also be useful as predictive biomarkers or drug targets for human pregnancy disorders.
Project description:We studied the heterogeneity among human KIR/NKG2A+CD8+ T cells. First, we found that KIRs and NKG2A are expressed on human CD8+ T cells in a mutually exclusive manner. Therefore, we compared KIR+CD8+ and NKG2A+CD8+ T cells in regards to TCR overlap and transcriptomic profiles and demonstrated that KIR+CD8+ and NKG2A+CD8+ T cells are distinct innate-like populations.