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: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:γδ and αβ T cells have unique roles in immunity and both originate in the thymus from T-lineage committed precursors through distinct but unclear mechanisms. Here, we show that Notch1 activation is more stringently required for human γδ development compared to αβ-lineage differentiation and performed paired mRNA and miRNA profiling across 11 discrete developmental stages of human T cell development in an effort to identify the potential Notch1 downstream mechanism. Our data suggest that the miR-17-92 cluster is a Notch1 target in immature thymocytes and that miR-17 can restrict BCL11B expression in these Notch-dependent T cell precursors. We show that enforced miR-17 expression promotes human γδ T cell development and, consistently, that BCL11B is absolutely required for αβ but less for γδ T cell development. This study suggests that human γδ T cell development is mediated by a stage-specific Notch-driven negative feedback loop through which miR-17 temporally restricts BCL11B expression and provides functional insights into the developmental role of the disease-associated genes BCL11B and the miR-17-92 cluster in a human context.