Early immunologic events at the tick-host interface

Ixodes species ticks are competent vectors of tick-borne viruses including tick-borne encephalitis and Powassan encephalitis.  Tick saliva has been shown to facilitate and enhance viral infection.  This likely occurs by saliva-mediated modulation of host responses into patterns favorable for viral infection and dissemination.  Because of the rapid kinetics of tick-borne viral transmission, this modulation must occur as early as tick attachment and initiation of feeding.  In this study, the gene expression profile of cutaneous bite-site lesions created by uninfected ticks were analyzed at 1, 3, 6, and 12 hours after Ixodes scapularis nymphal tick attachment to discover host pathways or responses potentially important in tick-borne viral establishment. Four milimeter ear biopsies from BALB/cJ mice infested with Ixodes scapularis nymphs were assayed using Affymetrix genechip 430A 2.0 arrays at 1, 3, 6, and 12 hours after infestation during a primary exposure. 3 mice were measured at each time point. Controls were 3 similarly housed but tick-free mice.