Decreased herpes simplex viral immunity and enhanced pathogenesis following stressor administration in mice.

Mild electric footshock stress was delivered during the dark portion of a 12:12 h light:dark cycle to C57BL/6 female mice that were infected with herpes simplex virus-type 1 (HSV). The studies were designed to correlate viral titer with both humoral and cell-mediated immune responses to HSV infection. Footshock was observed to result in decreased HSV-specific immunity. The numbers of leukocytes in spleens and draining popliteal lymph nodes of footshocked mice were depressed compared to both apparatus control and home cage control mice. A significant suppression of the HSV-specific cytotoxic T lymphocyte (CTL) response was observed in both the spleen and popliteal lymph nodes of footshocked mice. Serum IgM anti-HSV antibody titers were also depressed in footshocked mice. These changes were shown to be correlated with significantly increased viral titers in footshocked mice compared to control mice. These data demonstrate that administration of a relatively mild stressor is associated with depressed HSV-specific cellular and humoral immunity and is associated with increased pathogenicity.