Project description:Most tissue-resident macrophage populations develop during embryogenesis, self-renew in the steady state, and can expand during type 2 immunity. Whether shared mechanisms regulate macrophage proliferation in homeostasis and disease is unclear. We found that the transcription factor Bhlhe40 was cell-intrinsically required in large peritoneal macrophages (LPMs) for self-renewal and maintenance, but was not required in other resident macrophages. Bhlhe40 was selectively necessary in LPMs for proliferation, but not polarization, in response to IL-4. During a helminth infection, Bhlhe40 was required for normal LPM cell cycling. Bhlhe40 repressed the expression of Maf and Mafb and directly promoted expression of cell cycle-related transcripts to enable proliferation of LPMs. Genomic sites bound by Bhlhe40 in LPMs included some co-bound by the macrophage lineage-determining factor PU.1 and others uniquely bound by Bhlhe40, including Maf and cell cycle-related loci. Our findings demonstrate a tissue-specific control mechanism regulating resident macrophage proliferation in homeostasis and type 2 immunity.
Project description:Most tissue-resident macrophage populations develop during embryogenesis, self-renew in the steady state, and can expand during type 2 immunity. Whether shared mechanisms regulate macrophage proliferation in homeostasis and disease is unclear. We found that the transcription factor Bhlhe40 was cell-intrinsically required in large peritoneal macrophages (LPMs) for self-renewal and maintenance, but was not required in other resident macrophages. Bhlhe40 was selectively necessary in LPMs for proliferation, but not polarization, in response to IL-4. During a helminth infection, Bhlhe40 was required for normal LPM cell cycling. Bhlhe40 repressed the expression of Maf and Mafb and directly promoted expression of cell cycle-related transcripts to enable proliferation of LPMs. Genomic sites bound by Bhlhe40 in LPMs included some co-bound by the macrophage lineage-determining factor PU.1 and others uniquely bound by Bhlhe40, including Maf and cell cycle-related loci. Our findings demonstrate a tissue-specific control mechanism regulating resident macrophage proliferation in homeostasis and type 2 immunity.
Project description:Microarray data on TH17 cells from Bhlhe40-GFP reporter mice We used microarrays to detail the global programme of gene expression in polarized Bhlhe40-GFPneg and Bhlhe40-GFPpos TH17 cells Purified naïve CD4 T cells from spleen were polarized under TH17 condition in vitro. On day 4, cells were stimulated with PMA and ionomycin, and sorted by their Bhlhe40-GFP expression prior to microarray analysis
Project description:To investigate CD163-related signals and cytokine production, mRNA expression of resident peritoneal marophages derived from wild type mice and CD163-deficient mice was analyzed.
Project description:Tissue resident macrophages are notoriously heterogeneous, exhibiting discrete phenotypes as a consequence of tissue- and micro-anatomical niche-specific functions, but the molecular basis for this is not understood. We resolved a restricted transcriptional profile for the self-renewing population of peritoneal resident macrophages, which is expressed during homeostasis and inflammation and distinct from other MM-CM-^X. Prominent within this profile was the expression of Gata6. This study represents a characterisation of the role of Gata6 in peritoneal resident macrophage phenotype. We used microarrays to determine the patterns of gene expression in peritoneal resident MM-CM-^X in the absence of GATA-6 against wild type. Conditional 'floxed' Gata6 deficient sex-matched mice between 7 weeks old were compared against wild type
Project description:Tissue-resident memory CD8+ T cells (Trm) share characteristics and core residency gene programs with tumor-infiltrating lymphocytes (TILs). However, the transcriptional, metabolic and epigenetic regulation of Trm cell and TIL differentiation, maintenance and function are largely undefined. Furthermore, it is unknown whether metabolic and epigenetic manipulations can be employed to promote Trm/TIL functional programs for cancer immunotherapy. Here we report a critical mechanism programming the mitochondrial and epigenetic regulation of Trm/TIL functionality in situ. We found that mouse and human Trm/TIL expressed the transcription factor BHLHE40 and the BHLHE40-associated gene signature. Bhlhe40 was specifically required for Trm and TIL development and polyfunctionality. Local PD-1 signaling inhibited TIL Bhlhe40 expression, and Bhlhe40 was critical for TILs reinvigoration following anti-PD therapy. Mechanistically, Bhlhe40 sustained Trm/TIL mitochondrial fitness for the promotion of a functional epigenetic state. Building on these findings, we also identified an epigenetic and metabolic regimen that promoted Trm/TIL gene signatures associated with tissue residency and poly-functionality through in vitro T cell screening. Strikingly, this regimen empowered the anti-tumor activity of CD8+ T cells and possessed therapeutic potential even at an advanced tumor stage in mouse models. Our results provide mechanistic insights on the local regulation of Trm and TIL function, and offer a viable strategy for developing novel immunotherapeutic means for cancer.
Project description:microRNA transcriptome data from wild type and Gata6-deficient tissue resident peritoneal macrophages. Tissue resident macrophages are notoriously heterogeneous, exhibiting discrete phenotypes as a consequence of tissue- and micro-anatomical niche-specific functions, but the molecular basis for this is not understood. Gata6 itself has been shown to be a target of multiple miR. However, microRNA transcriptome and its dependence on tissue-specific macrophage programming, such as effected by GATA6, has not been explored. We used microRNA sequencing to determine the patterns of microRNA expression in peritoneal resident macrophages at homeostasis in the absence of GATA-6 against wild type.
Project description:NK cells represent a cellular component of the mammalian innate immune system, and mount rapid responses against viral infection, including the secretion of the potent anti-viral effector cytokine IFN-g. Following mouse cytomegalovirus (MCMV) infection, Bhlhe40 was the most highly induced transcription factor in NK cells among the basic helix-loop-helix family. Bhlhe40 upregulation in NK cells depended upon IL-12 and IL-18 signals, with the promoter of Bhlhe40 enriched for STAT4 and the permissive histone H3K4me3, and STAT4-deficient NK cells showing an impairment of Bhlhe40 induction and diminished H3K4me3. Transcriptomic and protein analysis of Bhlhe40-deficient NK cells revealed a defect in IFN-g production during MCMV infection, resulting in diminished protective immunity following viral challenge. Finally, we provide evidence that Bhlhe40 directly promotes IFN-g by binding throughout the Ifng loci in activated NK cells. Thus, our study reveals how STAT4-mediated control of Bhlhe40 drives protective IFN-g secretion by NK cells during viral infection.