inhibits spontaneous apoptosis and extends human neutrophil lifespan.

is a Gram-negative bacterium that is closely related to the highly virulent facultative intracellular pathogen, Data published by us and others demonstrate that virulence correlates directly with its ability to impair constitutive apoptosis and extend human neutrophil lifespan. In contrast, is attenuated in humans, and the mechanisms that account for this are incompletely defined. Our published data demonstrate that binds natural IgG that is present in normal human serum, which in turn, elicits NADPH oxidase activation that does not occur in response to As it is established that phagocytosis and oxidant production markedly accelerate neutrophil death, we predicted that may influence the neutrophil lifespan in an opsonin-dependent manner.

Francisella tularensis inhibits the intrinsic and extrinsic pathways to delay constitutive apoptosis and prolong human neutrophil lifespan.

Francisella tularensis is a facultative intracellular bacterium that infects many cell types, including neutrophils. We demonstrated previously that F. tularensis inhibits NADPH oxidase assembly and activity and then escapes the phagosome to the cytosol, but effects on other aspects of neutrophil function are unknown.