Virus Elimination in Acute Lymphocytic Choriomeningitis Virus Infection.

The immunological effector mechanism responsible for the elimination of virus in murine acute non-fatal extracranial lymphocytic choriomeningitis virus infection was studied. In this infection virus clearance is generally regarded as the result of a direct action of virus-specific cytotoxic T cells (T_c cells) on virus-producing target cells in the infected mouse. However, by manipulating the antiviral immune response by pretreatment with various doses of cyclophosphamide, we found lack of correlation between T_c cell activity and the clearance of virus. In contrast, we observed a conspicuous correlation between the host's ability to mount a virus-specific delayed-type hypersensitivity (DTH) response and its capacity to combat virus. Moreover, pretreatment with silica and carragheenan prolonged viraemia without impairment of the peak T_c cell response. These findings indicate that T_c cells have little or no capacity to eliminate virus, at least in the absence of an inflammatory response, and our findings suggest that virus clearance reflects a DTH-like process. [ABSTRACT FROM AUTHOR]