Gut Microbes Egested during Bites of Infected Sand Flies Augment Severity of Leishmaniasis via Inflammasome-Derived IL-1? (Cell Host & Microbe)

Neutrophils recruited to sand fly bite sites shelter Leishmania, augmenting disease. Dey et al. demonstrate that egestion of sand fly gut microbes into host skin primes the inflammasome to produce IL-1?, which sustains neutrophil recruitment. Removing gut microbiota or blocking IL-1? before transmission abolishes neutrophil recruitment and impairs Leishmania dissemination.