Host immune response to vesicular stomatitis virus infection of the central nervous system in C57BL/6 mice

In this report, the kinetics of cellular inflammatory changes in the brains of vesicular stomatitis virus (VSV)-infected C57BL/6 (B6) mice was determined. The behavior and survival rate of infected B6 were carefully monitored each day. Infectious viral titers and VSV antigen distribution were determined at several time points during the course of infection. Strong activation of both astrocytes and microglia was observed after VSV infection. Induction of type II nitric oxide synthase (iNOS) was detected in activated microglia in the olfactory bulb (ΩB) starting at day 4 postinfection. Induced expression of major histocompatibility complex (MHC) molecules and rapid infiltration of both T cells and natural killer (NK) cells were detected in the VSV-infected CNS. Collectively, these data indicate that the response to CNS infection in B6 mice, which is often primarily Th1 in characteristics, is comparable to BALB/c mice, a strain that often shows a Th2-dominated immune response.