Local Cell‐Mediated Immunity in Vaccinia Meningitis of Mice

Importance of cell mediated immunity (CMI) in the host defense mechanism against viral infection has amply demonstrated in various virus-host systems (5-7), and much interest in local CMI to a variety of viral infection has recently been provoked as shown by many laboratory reports (1, 3). In this connection, a study on the CMI in the meninges seems to be important for two reasons. First, the CMI in the meninges might control the outcome of viral meningitis. Secondly, it is conceivable that the cerebral cavity may be separated from the systemic immune reactions, conforming a separate immunologic domain. In vaccinia meningitis of mice, it is well known that mononuclear cells are accumulated locally (2). However, to date, the significance of these inflammatory cells in the host defense mechanism against viral infection remains yet to be elucidated. We describe the occurrence of CMI in mice against vaccinia virus in vaccinia meningitis. Eight to 10 weeks old DDD mice were inoculated intracerebrally (i.c.) with Dairen I strain of vaccinia virus (1.2 •~ 104 PFU/capita). At intervals thereafter, animals were sacrificed and examined for antigens detectable by immunofluorescence as well as for histological changes. Viral antigens began to be seen on the 3rd day