Intradermal route of infection with Francisella tularensis subspp novicida elicits differential induction of a wide array of cytokines and chemokines (117.7)

Abstract

Francisella tularensis is highly virulent and infectious bacterial pathogen and a category A select agent. Many aspects of immunity to the infection are not well understood. This study is part of ongoing work to understand the immune response following cutaneous exposure. The aim of the study was to determine cytokines/chemokines induced in response to intradermal infection with F. tularensis subspp novicida. Further aim was to determine the correlation between induction of cytokines/chemokines with bacterial load. C57BL/6J mice were intradermally infected with F. novicida U112 WT and DotU. DotU mutants do not grow inside macrophages and are greatly attenuated. The results investigated wide array of induced anti-and pro-inflammatory cytokines/chemokines in spleen. Higher levels of INF-γ and P-10 were expressed at 24hrs post-infection in spleen of mice infected with WT compared to DotU or mock control. The recovered number of viable bacteria from the spleen peaked at 24hrs and correlated with increased induction of INF-γ. Studies are underway to elucidate the role of cytokines/chemokines in shaping adaptive immunity.