Acc1 determines memory potential of individual CD4+ T cells by regulating de novo fatty acid biosynthesis [microarray]
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ABSTRACT: Immunological memory is central to adaptive immunity and protection from disease. Changing metabolic demands as antigen-specific T cells transition from effector to memory have been well documented, but the cell-specific pathways and molecules that govern this transition are poorly defined. ACC1 is a rate-limiting enzym in fatty acid biosynthesis. We show that genetic deletion of ACC1 enhanced the formation of CD4+ T cell memory, and that inhibition of ACC1 function enhanced memory T cell formation during parasite infection in mice. ACC1-deficient effector Th cells had similar metabolic signatures to wild-type memory Th cells, and Acaca expression was inversely correlated with a memory gene signature in individual cells. Single cell analysis allowed us to identify a memory precursor-enriched population (CCR7hiCD137lo) present during early differentiation of effector CD4+ T cells. Thus, fatty acid metabolism directs cell fate determination during the generation of memory CD4+ T cells.
Project description:Immunological memory is central to adaptive immunity and protection from disease. Changing metabolic demands as antigen-specific T cells transition from effector to memory have been well documented, but the cell-specific pathways and molecules that govern this transition are poorly defined. ACC1 is a rate-limiting enzym in fatty acid biosynthesis. We show that genetic deletion of ACC1 enhanced the formation of CD4+ T cell memory, and that inhibition of ACC1 function enhanced memory T cell formation during parasite infection in mice. ACC1-deficient effector Th cells had similar metabolic signatures to wild-type memory Th cells, and Acaca expression was inversely correlated with a memory gene signature in individual cells. Single cell analysis allowed us to identify a memory precursor-enriched population (CCR7hiCD137lo) present during early differentiation of effector CD4+ T cells. Thus, fatty acid metabolism directs cell fate determination during the generation of memory CD4+ T cells.
Project description:Immunological memory is central to adaptive immunity and protection from disease. Changing metabolic demands as antigen-specific T cells transition from effector to memory have been well documented, but the cell-specific pathways and molecules that govern this transition are poorly defined. ACC1 is a rate-limiting enzym in fatty acid biosynthesis. We show that genetic deletion of ACC1 enhanced the formation of CD4+ T cell memory, and that inhibition of ACC1 function enhanced memory T cell formation during parasite infection in mice. ACC1-deficient effector Th cells had similar metabolic signatures to wild-type memory Th cells, and Acaca expression was inversely correlated with a memory gene signature in individual cells. Single cell analysis allowed us to identify a memory precursor-enriched population (CCR7hiCD137lo) present during early differentiation of effector CD4+ T cells. Thus, fatty acid metabolism directs cell fate determination during the generation of memory CD4+ T cells.
Project description:T cells possess distinguishing effector functions and drive inflammatory disorders. We have previously identified IL-5-producing Th2 cells as the pathogenic population predominantly involved in the pathology of allergic inflammation. However, the cell-intrinsic signaling pathways that control the pathogenic Th2 cell function are still unclear. We herein report the high expression of acetyl-CoA carboxylase 1 (ACC1) in pathogenic CD4+ T cell population in the lung and skin. The genetic deletion of CD4+ T cell-intrinsic ACC1 dampened eosinophilic and basophilic inflammation in the lung and skin by constraining IL-5 or IL-3 production. Mechanistically, ACC1-dependent fatty acid biosynthesis induces the pathogenic cytokine production of CD4+ T cells via metabolic reprogramming and the availability of acetyl-CoA for epigenetic regulation. We thus identified a distinct phenotype of the pathogenic T cell population in the lung and skin, and ACC1 was shown to be an essential regulator controlling the pathogenic function of these populations to promote type 2 inflammation.
Project description:In order to propagate a solid tumor, cancer cells must adapt to and survive under various tumor microenvironment (TME) stresses, such as hypoxia or lactic acidosis. To systematically identify genes that modulate cancer cell survival under stresses, we performed genome-wide shRNA screens under hypoxia or lactic acidosis. We discovered that genetic depletion of acetyl-CoA carboxylase (ACACA or ACC1) or ATP citrate lyase (ACLY) protected cancer cells from hypoxia-induced apoptosis. Additionally, loss of ACLY or ACC1 reduced levels and activities of the oncogenic transcription factor ETV4. Silencing ETV4 also protected cells from hypoxia-induced apoptosis and led to remarkably similar transcriptional responses as with silenced ACLY or ACC1, including an anti-apoptotic program. Metabolomic analysis found that while α-ketoglutarate levels decrease under hypoxia in control cells, α-ketoglutarate is paradoxically increased by hypoxia when ACC1 or ACLY are depleted. Supplementation with α-ketoglutarate rescued the hypoxia-induced apoptosis and recapitulated the decreased expression and activity of ETV4 via an epigenetic mechanism. Therefore, ACC1 and ACLY regulate the levels of ETV4 under hypoxia via increased α-ketoglutarate. These results reveal that ACC1/ACLY- α-ketoglutarate-ETV4 is a novel means by which metabolic states regulate transcriptional output for life vs. death decisions under hypoxia. Since many lipogenic inhibitors are under investigation as cancer therapeutics, our findings suggest that the use of these inhibitors will need to be carefully considered with respect to oncogenic drivers, tumor hypoxia, progression and dormancy. More broadly, our screen provides a framework for studying additional tumor cell stress-adaption mechanisms in the future. DESIGN: H1975 lung cancer cells transduced with a scramble shRNA hairpin or two different shRNAs against ACLY, ACC1, or ETV4 under hypoxia.
Project description:In order to propagate a solid tumor, cancer cells must adapt to and survive under various tumor microenvironment (TME) stresses, such as hypoxia or lactic acidosis. To systematically identify genes that modulate cancer cell survival under stresses, we performed genome-wide shRNA screens under hypoxia or lactic acidosis. We discovered that genetic depletion of acetyl-CoA carboxylase (ACACA or ACC1) or ATP citrate lyase (ACLY) protected cancer cells from hypoxia-induced apoptosis. Additionally, loss of ACLY or ACC1 reduced levels and activities of the oncogenic transcription factor ETV4. Silencing ETV4 also protected cells from hypoxia-induced apoptosis and led to remarkably similar transcriptional responses as with silenced ACLY or ACC1, including an anti-apoptotic program. Metabolomic analysis found that while α-ketoglutarate levels decrease under hypoxia in control cells, α-ketoglutarate is paradoxically increased by hypoxia when ACC1 or ACLY are depleted. Supplementation with α-ketoglutarate rescued the hypoxia-induced apoptosis and recapitulated the decreased expression and activity of ETV4 via an epigenetic mechanism. Therefore, ACC1 and ACLY regulate the levels of ETV4 under hypoxia via increased α-ketoglutarate. These results reveal that ACC1/ACLY- α-ketoglutarate-ETV4 is a novel means by which metabolic states regulate transcriptional output for life vs. death decisions under hypoxia. Since many lipogenic inhibitors are under investigation as cancer therapeutics, our findings suggest that the use of these inhibitors will need to be carefully considered with respect to oncogenic drivers, tumor hypoxia, progression and dormancy. More broadly, our screen provides a framework for studying additional tumor cell stress-adaption mechanisms in the future.
Project description:Memory helper T (Th) cells are crucial for secondary immune responses against infectious microorganisms but also drive the pathogenesis of chronic inflammatory diseases. Therefore, it is of fundamental importance to understand how memory T cells are generated. However, the molecular mechanisms governing memory Th cell generation remain incompletely understood. Here, we identified CD30 as a molecule heterogeneously expressed on effector Th1 and Th17 cells, and CD30hi effector Th1 and Th17 cells preferentially generated memory Th1 and Th17 cells. We found that CD30 mediated signal induced Transglutaminase-2 (TG2) expression, and that the TG2 expression in effector Th cells is essential for memory Th cell generation. In fact, Cd30-deficiency resulted in the impaired generation of memory Th1 and Th17 cells, which can be rescued by overexpression of TG2. Furthermore, transglutaminase-2 (Tgm2)-deficient CD4 T cells failed to become memory Th cells. As a result, T cells from Tgm2-deficient mice displayed impaired antigen-specific antibody production and attenuated Th17-mediated allergic responses. Our data indicate that CD30-induced TG2 expression in effector Th cells is essential for the generation of memory Th1 and Th17 cells, and that CD30 can be a marker for precursors of memory Th1 and Th17 cells.