Project description:We recently found that a unique subset of innate-like γδ T cells develop from the DN2a-stage of the fetal thymus independent of the zinc-finger transcription factor B-cell leukemia/lymphoma 11b (Bcl11b). Herein we characterized these Bcl11b-independent γδ T cells in the periphery as CD5−NK1.1+ and Granzyme B+, and show that they are capable of producing interferon (IFN)-γ upon T cell receptor stimulation without Ca2+ influx. In wild-type mice, these cells were sparse in lymphoid tissues but abundant in non-lymphoid tissues such as the liver. Bcl11b-independent CD5−NK1.1+ γδ T cells appeared and contributed to early protection before Bcl11b-dependent CD5+NK1.1− γδT cells following Listeria monocytogenes infection, recapitulating their appearance during thymic development.
Project description:TCR γ chain loci of mice have seven variable (Vγ) gene segments (Vγ1, Vγ2, Vγ3, Vγ4, Vγ5, Vγ6, and Vγ7) using the Heilig and Tonegawa nomenclature. Vγ6+ γδ T cells, which develop in the thymus at the perinatal stage, are distributed within the mucosal tissues in the periphery. Vγ6+ γδ T cells are exclusive interleukin (IL)-17 producers among γδ T cells, and Vγ6+ IL-17A+ γδ T (γδT17) cells play important roles in protection against microbial infection and in the pathogenesis of inflammatory diseases, such as colitis and autoimmune diseases. We have previously reported that γδT17 cells develop from the CD4–CD8– (DN)2b stage in the thymus at the prenatal stage in a Bcl11b-dependent manner. However, details of the development of Vγ6+ γδT17 cells remain obscure. To analyze Vγ6+ γδ T cells in detail, we recently developed a monoclonal antibody (mAb; termed 1C10-1F7) specific to mouse Vg6 chain. Use of this mAb revealed that Vγ6+ γδ T cells in 0-day-old thymus were co-localized with medullary thymic epithelial cells (mTECs), which regulate T cell tolerance by self-antigen presentation using major histocompatibility complex (MHC) class II. Here, we report that MHC class II in the thymus inhibits the generation of Vγ6+ γδT17 cells.
Project description:Notch-dependent BCL11B induction converts thymus seeding precursor cells into committed T cell progenitors that subsequently differentiate into T cells bearing either the γδ or αβ T cell receptor. In human, strong Notch activation favors γδ T cell development at the expense of αβ-lineage differentiation, but the underlying molecular mechanism has remained unclear. Therefore, we performed paired mRNA and miRNA profiling across 11 stages of human T cell development, including developing γδ T cells. We identify the miR-17-92 cluster as a direct Notch target and show that miR-17 promotes human TCRγδ T cell development by targeting BCL11B, a gene required for αβ but not for γδ T cell development. Thus, following its role as a licensing factor to induce BCL11B expression in early T cell precursors, Notch activation limits BCL11B expression through miR-17 until thymocytes have passed the β-selection checkpoint when Notch activation is turned off. Hereby Notch prevents premature BCL11B upregulation that is required for αβ-lineage differentiation and this results in preferential γδ-lineage differentiation. Our work unravels a dual role for Notch in controlling BCL11B expression during intrathymic differentiation and provides a unique resource for understanding the mRNA/miRNA interactions that control human T cell development. The expression of 756 miRNAs was determined using the Taqman stem-loop RT-qPCR method as previously described (Mets E. Leukemia. 2015, Mavrakis KJ. Nat Genet. 2011).
Project description:Notch-dependent BCL11B induction converts thymus seeding precursor cells into committed T cell progenitors that subsequently differentiate into T cells bearing either the γδ or αβ T cell receptor. In human, strong Notch activation favors γδ T cell development at the expense of αβ-lineage differentiation, but the underlying molecular mechanism has remained unclear. Therefore, we performed paired mRNA and miRNA profiling across 11 stages of human T cell development, including developing γδ T cells. We identify the miR-17-92 cluster as a direct Notch target and show that miR-17 promotes human TCRγδ T cell development by targeting BCL11B, a gene required for αβ but not for γδ T cell development. Thus, following its role as a licensing factor to induce BCL11B expression in early T cell precursors, Notch activation limits BCL11B expression through miR-17 until thymocytes have passed the β-selection checkpoint when Notch activation is turned off. Hereby Notch prevents premature BCL11B upregulation that is required for αβ-lineage differentiation and this results in preferential γδ-lineage differentiation. Our work unravels a dual role for Notch in controlling BCL11B expression during intrathymic differentiation and provides a unique resource for understanding the mRNA/miRNA interactions that control human T cell development. The expression of 756 miRNAs and 3 small RNA controls was determined using the Taqman stem-loop RT-qPCR method as previously described (Mets E. Leukemia. 2015, Mavrakis KJ. Nat Genet. 2011).
Project description:Notch-dependent BCL11B induction converts thymus seeding precursor cells into committed T cell progenitors that subsequently differentiate into T cells bearing either the γδ or αβ T cell receptor. In human, strong Notch activation favors γδ T cell development at the expense of αβ-lineage differentiation, but the underlying molecular mechanism has remained unclear. Therefore, we performed paired mRNA and miRNA profiling across 11 stages of human T cell development, including developing γδ T cells. We identify the miR-17-92 cluster as a direct Notch target and show that miR-17 promotes human TCRγδ T cell development by targeting BCL11B, a gene required for αβ but not for γδ T cell development. Thus, following its role as a licensing factor to induce BCL11B expression in early T cell precursors, Notch activation limits BCL11B expression through miR-17 until thymocytes have passed the β-selection checkpoint when Notch activation is turned off. Hereby Notch prevents premature BCL11B upregulation that is required for αβ-lineage differentiation and this results in preferential γδ-lineage differentiation. Our work unravels a dual role for Notch in controlling BCL11B expression during intrathymic differentiation and provides a unique resource for understanding the mRNA/miRNA interactions that control human T cell development. We used microarrays in order to profile gene expression in CD34+ thymocytes before culture and after 5 or 10 days culture on OP9 stromal cells expressing Notch ligands JAG1, JAG2, DLL1 or DLL4.
Project description:Notch-dependent BCL11B induction converts thymus seeding precursor cells into committed T cell progenitors that subsequently differentiate into T cells bearing either the γδ or αβ T cell receptor. In human, strong Notch activation favors γδ T cell development at the expense of αβ-lineage differentiation, but the underlying molecular mechanism has remained unclear. Therefore, we performed paired mRNA and miRNA profiling across 11 stages of human T cell development, including developing γδ T cells. We identify the miR-17-92 cluster as a direct Notch target and show that miR-17 promotes human TCRγδ T cell development by targeting BCL11B, a gene required for αβ but not for γδ T cell development. Thus, following its role as a licensing factor to induce BCL11B expression in early T cell precursors, Notch activation limits BCL11B expression through miR-17 until thymocytes have passed the β-selection checkpoint when Notch activation is turned off. Hereby Notch prevents premature BCL11B upregulation that is required for αβ-lineage differentiation and this results in preferential γδ-lineage differentiation. Our work unravels a dual role for Notch in controlling BCL11B expression during intrathymic differentiation and provides a unique resource for understanding the mRNA/miRNA interactions that control human T cell development. We used microarrays in order to profile the gene expression in 11 ex vivo T cell subsets, isolated from human thymus. Cord blood CD34+Lin- HPCs were used as a reference subset for extrathymic HPCs.
Project description:In thymus hematopoietic precursor cells differentiate into αβ T cells, γδ T cells, mucosa-associated invariant T cells (MAIT), and natural killer T (NKT) cells. We show that both ablation of NFATc1 or its induction during the DN stages of thymocyte development leads to an almost normal thymocyte development but a marked increase in γδ T cells. The γδ cells deficient for NFATc1 acquire an NKT γδ cell phenotype that exhibits the expression of CD4 co-receptor, the NK1.1 marker, the augmented usage of the Vγ1.1 and Vδ6.3 segments, and an increased in IL4 and IFN-γ production.
Project description:In thymus hematopoietic precursor cells differentiate into αβ T cells, γδ T cells, mucosa-associated invariant T cells (MAIT), and natural killer T (NKT) cells. We show that both ablation of NFATc1 or its induction during the DN stages of thymocyte development leads to an almost normal thymocyte development but a marked increase in γδ T cells. The γδ cells deficient for NFATc1 acquire an NKT γδ cell phenotype that exhibits the expression of CD4 co-receptor, the NK1.1 marker, the augmented usage of the Vγ1.1 and Vδ6.3 segments, and an increased in IL4 and IFN-γ production.
Project description:In thymus hematopoietic precursor cells differentiate into αβ T cells, γδ T cells, mucosa-associated invariant T cells (MAIT), and natural killer T (NKT) cells. We show that both ablation of NFATc1 or its induction during the DN stages of thymocyte development leads to an almost normal thymocyte development but a marked increase in γδ T cells. The γδ cells deficient for NFATc1 acquire an NKT γδ cell phenotype that exhibits the expression of CD4 co-receptor, the NK1.1 marker, the augmented usage of the Vγ1.1 and Vδ6.3 segments, and an increased in IL4 and IFN-γ production.
Project description:γδ T cells producing interleukin 17A (IL-17A), which are mainly Vγ4 and Vγ6 subsets, are involved in protection against infection by extracellular bacteria. Using a new Vγ6-specific monoclonal antibody (mAb) (1C10-1F7) which we recently developed, we found that IL-17A+ Vγ6+ γδ T cells increased predominantly in the peritoneal cavity compared with IL-17A+ Vγ4+ γδ T cells during intraperitoneal Escherichia coli infection. The number of IL-17A+ Vγ6+ γδ T cells, which rapidly became CD69+ from CD69-, peaked at 12 h after infection. In vivo treatment with 1C10-1F7 mAb significantly inhibited the accumulation of neutrophils and hampered the resolution of E. coli infection. These results suggest that rapid activation of IL-17A+ Vγ6+ γδ T cells contributed to host defence against E. coli infection.