The role of lipids in host–pathogen interactions

Abstract

Innate immunity relies on the effective recognition and elimination of pathogenic microorganisms. This entails sequestration of pathogens into phagosomes that promptly acquire microbicidal and degradative properties. This complex series of events, which involve cytoskeletal reorganization, membrane remodeling and the activation of multiple enzymes, is orchestrated by lipid signaling. To overcome this immune response, intracellular pathogens acquired mechanisms to subvert phosphoinositide-mediated signaling and use host lipids, notably cholesterol, as nutrients. We present brief overviews of the role of phosphoinositides in phagosome formation and maturation as well as of cholesterol handling by host cells, and selected Salmonella, Shigella, Chlamydia and Mycobacterium tuberculosis to exemplify the mechanisms whereby intracellular pathogens co-opt lipid metabolism in host cells. © 2018 IUBMB Life, 70(5):384-392, 2018.

The fungal peptide toxin Candidalysin activates the NLRP3 inflammasome and causes cytolysis in mononuclear phagocytes

“…7a ), suggesting that phagosomal destabilization is also not involved in Candidalysin-dependent inflammasome activation. Similarly, co-localization of Wt, ece1 Δ/Δ, or ece1 Δ/Δ + ECE1 Δ184–279 cells with the late endo(lyso)somal marker LAMP1, the late maturation markers Phosphatidylinositol 4-phosphate (PI(4)P) and Rab7 41 , as well as with the acidic organelle dye LysoTracker, indicated that phagosome maturation is not affected by Ece1 (Fig. 7a–g ).…”

The Dual Function of the Fungal Toxin Candidalysin during Candida albicans—Macrophage Interaction and Virulence

“…Upon phagocytosis of fungal cells, the nascent phagosome matures through fusion steps with lysosomes, ultimately forming the phagolysosome. This cellular compartment represents a hostile environment for the fungus characterized by low pH, few nutrients, and antimicrobial activities (such as oxidative, nitrosative, and proteolytic stress) [36,37].…”

Candida albicans Hyphal Expansion Causes Phagosomal Membrane Damage and Luminal Alkalinization

“…To prevent microbial dissemination from the gut, macrophages and neutrophils quickly recognize and engulf invading microbes through phagocytosis. After engulfment of microbial cells by macrophages, the nascent phagosome undergoes a series of fusion and fission events with endosomes and lysosomes, a phenomenon referred to collectively as “phagosome maturation” (see reference 6 for a review). Fusion of the nascent phagosome with endosomes and lysosomes induces a progressive luminal acidification.…”