Reverting the mode of action of the mitochondrial F O F 1-ATPase by Legionella pneumophila preserves its replication niche

Lien vers Pubmed [PMID] – 34882089

Lien DOI – 10.7554/eLife.71978

Elife. 2021 Dec 9;10:e71978. doi: 10.7554/eLife.71978. Online ahead of print

Legionella pneumophila, the causative agent of Legionnaires’; disease, a severe pneumonia, injects via a type-IV-secretion-system (T4SS) more than 300 proteins into macrophages, its main host cell in humans. Certain of these proteins are implicated in reprogramming the metabolism of infected cells by reducing mitochondrial oxidative phosphorylation (OXPHOS) early after infection. Here we show that despite reduced OXPHOS, the mitochondrial membrane potential (Δψ_m) is maintained during infection of primary human monocyte-derived macrophages (hMDMs). We reveal that L. pneumophila reverses the ATP-synthase activity of the mitochondrial F_OF₁-ATPase to ATP-hydrolase activity in a T4SS-dependent manner, which leads to a conservation of the Δψ_m, preserves mitochondrial polarization and prevents macrophage cell death. Analyses of T4SS effectors known to target mitochondrial functions revealed that LpSpl is partially involved in conserving the Δψ_m, but not LncP and MitF. The inhibition of the L. pneumophila-induced ‘reverse mode’ of the F_OF₁-ATPase collapsed the Δψ_m and caused cell death in infected cells. Single-cell analyses suggested that bacterial replication occurs preferentially in hMDMs that conserved the Δψ_m and showed delayed cell death. This direct manipulation of the mode of activity of the F_OF₁-ATPase is a newly identified feature of L. pneumophila allowing to delay host cell death and thereby to preserve the bacterial replication niche during infection.