Cross-Species Interferon Signaling Boosts Microbicidal Activity within the Tick Vector.

ABSTRACT: Evolution of hematophagy in blood-sucking parasites likely involves communication with their hosts. We find that Ixodes ticks are responsive to IFN? acquired in a blood meal from mice infected with the Lyme disease-causing bacteria Borrelia burgdorferi, leading to induction of antimicrobial responses. Ixodes ticks parasitizing B. burgdorferi-infected mice upregulated an I. scapularis Rho-like GTPase (IGTPase). IGTPase knockdown enhanced B. burgdorferi levels in post-fed ticks, suggesting this protein controls spirochete survival. Notably, IGTPase was only induced during pathogen acquisition from mice and not upon transmission to naive hosts. Microinjection of ticks with IFN? induced IGTPase, and ticks parasitizing IFN? knockout mice, failed to upregulate IGTPase. Additionally, ticks lacking the transcription factor STAT, which signals downstream of IFN?, did not induce IGTPase. IGTPase expression induced antimicrobial peptides, including Dae2, previously shown to inhibit B. burgdorferi. These results identify an interspecies signaling cascade allowing ticks to detect invading bacteria and mount microbicidal responses.

SUBMITTER: Smith AA 

PROVIDER: S-EPMC4945435 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature