Salmonella Typhimurium impairs glycolysis-mediated acidification of phagosomes to evade macrophage defense

PLoS Pathog. 2021 Sep 23;17(9):e1009943. doi: 10.1371/journal.ppat.1009943. eCollection 2021 Sep.

Abstract

Regulation of cellular metabolism is now recognized as a crucial mechanism for the activation of innate and adaptive immune cells upon diverse extracellular stimuli. Macrophages, for instance, increase glycolysis upon stimulation with pathogen-associated molecular patterns (PAMPs). Conceivably, pathogens also counteract these metabolic changes for their own survival in the host. Despite this dynamic interplay in host-pathogen interactions, the role of immunometabolism in the context of intracellular bacterial infections is still unclear. Here, employing unbiased metabolomic and transcriptomic approaches, we investigated the role of metabolic adaptations of macrophages upon Salmonella enterica serovar Typhimurium (S. Typhimurium) infections. Importantly, our results suggest that S. Typhimurium abrogates glycolysis and its modulators such as insulin-signaling to impair macrophage defense. Mechanistically, glycolysis facilitates glycolytic enzyme aldolase A mediated v-ATPase assembly and the acidification of phagosomes which is critical for lysosomal degradation. Thus, impairment in the glycolytic machinery eventually leads to decreased bacterial clearance and antigen presentation in murine macrophages (BMDM). Collectively, our results highlight a vital molecular link between metabolic adaptation and phagosome maturation in macrophages, which is targeted by S. Typhimurium to evade cell-autonomous defense.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Gene Expression Profiling
  • Glycolysis / physiology*
  • Host-Pathogen Interactions / physiology*
  • Macrophages / metabolism*
  • Metabolomics
  • Mice
  • Phagosomes / metabolism*
  • Salmonella Infections, Animal / metabolism*
  • Salmonella typhimurium / metabolism

Grants and funding

NR received funding from CECAD D3, Deutsche Forschungsgemeinschaft (DFG), from SFB670 (N31) Deutsche Forschungsgemeinschaft (DFG); from Koeln Fortune and from University of South Australia (UniSA). SG was supported by funds from DFG; NJH and JF were supported by funds from German Center for Infection Research (DZIF). RG was supported by funds from UniSA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.