The initiation of the immune response at the cellular level relies on specific recognition molecules to rapidly signal viral infection via interferon (IFN) regulatory factor 3 (IRF-3)-dependent pathways. The absence of IRF-3 would be expected to render such pathways inoperative and thereby significantly affect viral infection. Unexpectedly, a previous study found no significant change in herpes simplex virus (HSV) pathogenesis in IRF-3-/- mice following intravenous HSV type 1 (HSV-1) challenge (K. Honda, H. Yanai, H. Negishi, M. Asagiri, M. Sato, T. Mizutani, N. Shimada, Y. Ohba, A. Takaoka, N. Yoshida, and T. Taniguchi, Nature 434:772-777, 2005). In contrast, the present study demonstrated that IRF-3-/- mice are significantly more susceptible to HSV infection via the corneal and intracranial routes. Following corneal infection with 2 × 106 PFU of HSV-1 strain McKrae, 50% of wild-type mice survived, compared to 10% of IRF-3-deficient mice. Significantly increased viral replication and inflammatory cytokine production were observed in brain tissues of IRF-3-/- mice compared to control mice, with a concomitant deficit in production of both IFN-β and IFN-α. These data demonstrate a critical role for IRF-3 in control of central nervous system infection following HSV-1 challenge. Furthermore, this work underscores the necessity to evaluate multiple routes of infection and animal models in order to fully determine the role of host resistance factors in pathogenesis.
ASJC Scopus subject areas
- Insect Science