Immune responses to vaginal or systemic infection of BALB/c mice with herpes simplex virus type 2.

The temporal relationships among the humoral and cellular immune responses were defined in BALB/c mice after vaginal or systemic infection with herpes simplex virus type 2 (HSV-2). After vaginal infection, mice showed evidence of clinical vaginitis on days 4 to 6 and HSV-2 replication was detected locally in the vaginal secretions, cervix, vagina, and uterus before the virus subsequently spread to the central nervous system. Death from encephalitis occurred between 7 and 10 days after infection. Vaginal infection was associated with significant delayed type hypersensitivity and splenic proliferative cell-mediated immune responses which appeared during the acute infection and waned by 3 weeks. There was almost no evidence of a systemic neutralizing antibody response at any time after vaginal infection. In contrast to the local vaginal infection, systemic i.v. HSV-2 infection induced a humoral response as well as the two cellular immune responses. Although both cellular immune responses appeared during the acute infection (days 6 to 14) and persisted for approximately 5 weeks, the humoral response appeared in surviving animals and persisted for at least 4 months. Thus, vaginal HSV-2 infection was associated primarily with transient cellular immune responses, whereas i.v. HSV-2 infection induced prolonged systemic humoral and cellular immune responses.