Project description:The lymphoid branch of the immune defense is composed of innate and adaptive immune cells. Using multiple genetic strategies we demonstrate that in the thymus E2A and HEB act in synergy to establish T cell identity and to suppress the aberrant development of innate lymphoid cells that include ILC2 and LTi-like cells. We found that E2A and HEB induce T cell fate by activating the expression of an ensemble of genes encoding for proteins associated with Notch- and pre-TCR signaling and to promote TCRβ antigen receptor assembly. We show that E2A and HEB act in early T progenitors (ETPs) to establish and maintain a T-lineage specific enhancer repertoire, including regulatory elements associated with the Notch1/3 and Rag1/2 gene loci. Based on these and previous observations we propose that the E-Id protein axis specifies innate versus adaptive lymphoid cell fate.
Project description:The lymphoid branch of the immune defense is composed of innate and adaptive immune cells. Using multiple genetic strategies we demonstrate that in the thymus E2A and HEB act in synergy to establish T cell identity and to suppress the aberrant development of innate lymphoid cells that include ILC2 and LTi-like cells. We found that E2A and HEB induce T cell fate by activating the expression of an ensemble of genes encoding for proteins associated with Notch- and pre-TCR signaling and to promote TCRβ antigen receptor assembly. We show that E2A and HEB act in early T progenitors (ETPs) to establish and maintain a T-lineage specific enhancer repertoire, including regulatory elements associated with the Notch1/3 and Rag1/2 gene loci. Based on these and previous observations we propose that the E-Id protein axis specifies innate versus adaptive lymphoid cell fate.
Project description:The type 2 helper effector program is driven by the master transcription factor GATA3 and can be expressed by subsets of both innate lymphoid cells (ILCs) and adaptive CD4+ T helper (Th) cells. While ILC2s and Th2 cells acquire their type 2 differentiation program under very different contexts, the distinct regulatory mechanisms governing this common program are only partially understood. Here we show that the differentiation of ILC2s, and their concomitant high level of GATA3 expression, are controlled by a Gata3 enhancer, Gata3 +674/762, that plays only a minimal role in Th2 cell differentiation. Mice lacking this enhancer exhibited defects in several but not all type 2 inflammatory responses, depending on the respective degree of ILC2 and Th2 cell involvement. Our study provides molecular insights into the different gene regulatory pathways leading to the acquisition of the GATA3-driven type 2 helper effector program in innate and adaptive lymphocytes.
Project description:Non-lymphoid tissues (NLTs) harbour a pool of adaptive immune cells distinct from their counterparts in lymphoid tissues, and their development and phenotype remains largely unexplored. We used scRNA-seq to survey CD4+ T regulatory (Treg) and memory T (Tmem) cells in spleen, lymph nodes, skin and colon in an unbiased way, in mouse and human. This cross-tissues, cross-species comparison allows us to obtain marker genes for immune populations in specific locations with likely relevance for human studies. Additionally, a continuous phenotype of Treg migration can be modelled from the mouse data, unravelling the transcriptional stages through which these cells transition between tissues.
Project description:Innate lymphoid cells (ILCs) play critical roles during innate immune responses to pathogens and lymphoid organ development. IL-7Ra+ ILC subsets, similar to T helper (Th) cell subsets, produce distinctive effector cytokines. The molecular control of IL-7Ra+ ILC development and maintenance has yet to be dissected. Here we report that GATA3 is indispensable for the development of all IL-7Ra+ ILC subsets and T cells. Gata3 conditional deficient mice have no lymph nodes and are susceptible to Citrobactor rodentium infection. Genome-wide gene analyses indicate that GATA3 regulates similar set of cytokines and receptors in ILC2s and Th2 cells and is critical for the maintenance of ILC2s. Thus, GATA3 plays parallel roles in establishing and regulating both adaptive and innate lymphocytes. To identify GATA3 regulated genes in type 2 innate lymphoid cells by tamoxifen-mediated acute deletion of Gata3 gene.
Project description:Dendritic cells (DCs) play a crucial role in the regulation of innate and adaptive immune responses. DCs initiate adaptive immune responses after their migration to secondary lymphoid organs, a process mainly driven by the expression of the chemokine receptor CCR7. LXR ligands/oxysterols released by tumors were shown to dampen DC migration to secondary lymphoid organs by the inhibition of CCR7 expression. We studied the gene expression modulation of DCs undergoing maturation (by LPS) in the presence of the oxysterol 22R-Hydroxycholesterol (22R-HC).
