Uncoupling of IL-6 signaling and LC3-associated phagocytosis drives immunoparalysis during sepsis.

Akoumianaki T, Vaporidi K, Diamantaki E, Pène F, Beau R, Gresnigt MS, Gkountzinopulou M, Venichaki M, Drakos E, El-Benna J, Samonis G, Le KTT, Kumar V, Georgopoulos D, van de Veerdonk FL, Netea MG, Latge JP, Chamilos G (2021) Uncoupling of IL-6 signaling and LC3-associated phagocytosis drives immunoparalysis during sepsis. Cell Host Microbe 29(8), 1277-1293.

Abstract

Immune deactivation of phagocytes is a central event in the pathogenesis of sepsis. Herein, we identify a master regulatory role of IL-6 signaling on LC3-associated phagocytosis (LAP) and reveal that uncoupling of these two processes during sepsis induces immunoparalysis in monocytes/macrophages. In particular, we demonstrate that activation of LAP by the human fungal pathogen Aspergillus fumigatus depends on ERK1/2-mediated phosphorylation of p47phox subunit of NADPH oxidase. Physiologically, autocrine IL-6/JAK2/Ninein axis orchestrates microtubule organization and dynamics regulating ERK recruitment to the phagosome and LC3+ phagosome (LAPosome) formation. In sepsis, loss of IL-6 signaling specifically abrogates microtubule-mediated trafficking of ERK, leading to defective activation of LAP and impaired killing of bacterial and fungal pathogens by monocytes/macrophages, which can be selectively restored by IL-6 supplementation. Our work uncovers a molecular pathway linking IL-6 signaling with LAP and provides insight into the mechanisms underlying immunoparalysis in sepsis.

Leibniz-HKI-Authors

Mark Gresnigt

Identifier

doi: 10.1016/j.chom.2021.06.002

PMID: 34214493