Methionine metabolism shapes immune response against Mycobacterium tuberculosis
The methionine metabolism is central to epigenetic reprogramming to produce pro-inflammatory cytokines. Disruptions in methionine metabolism contribute to complex disorders, providing an important target for nutrient interventions. Here, Mycobacterium tuberculosis (Mtb) H37Rv-infected C57BL/6 mice showed functional heterogeneity between alveolar and non-alveolar macrophage (AMs/Non-AMs) with major metabolic reprogramming in Non-AMs. Global metabolite and proteome analysis of Mtb-infected bone marrow-derived macrophages (BMDMs) showed a diversion of flux from methionine metabolism toward increased nucleotide salvage and glutathione (GSH) production. Carbon units of 13C5-methionine via isotopomer analysis contributed to polyamine synthesis, fuelling the nucleotide salvage node in Mtb-infected BMDMs. Methionine supplementation increased mycobacterial clearance in C57BL/6 mice and in BMDMs by promoting a pro-inflammatory response, as evident by increased IL-1{beta} and IFN-{gamma}. Increased IL-1{beta} production is mainly contributed to by increased H3K4 trimethylation in macrophages. These findings reveal an important strategy by which methionine supplementation in macrophages and mice remodels host metabolism to enhance acute pro-inflammatory responses and exploit dietary supplementation to improve nutritional immunity in TB. HighlightsO_LIMycobacterium tuberculosis (Mtb) infection decreases intracellular methionine levels and increases purine levels in primary macrophages. C_LIO_LIMethionine carbon units contribute to nucleotide salvage, and their restriction lowers IL-1 response and mycobacterial clearance. C_LIO_LIEx vivo methionine supplementation in Mtb-infected macrophages increases H3K4me3 at the Il-1b gene promoter and gene body, leading to an increased pro-inflammatory response and improved mycobacterial clearance. C_LIO_LIIn vivo methionine supplementation improved pro-inflammatory response in lungs, spleen and bone marrow, leading to accelerated mycobacterial clearance upon Mtb-H37Rv infection. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=157 SRC="FIGDIR/small/680834v2_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@1bf5corg.highwire.dtl.DTLVardef@ba4dbdorg.highwire.dtl.DTLVardef@145f23dorg.highwire.dtl.DTLVardef@122b2a2_HPS_FORMAT_FIGEXP M_FIG C_FIG