Immunopathology of Mouse Hepatitis Virus Type 3 Infection

Abstract

Normal adult A strain mice are resistant to MHV₃ infection. A strain mice immunosuppressed by 600 rads of x-irradiation or by anti-lymphocyte serum treatment became susceptible to the virus and died with specific lesions of the liver and high virus titers. However, mice immunized with MHV₃ before sublethal x-irradiation resisted a second injection of virus. Resistant adult (A × C3H) F₁ hybrids undergoing graft-vs-host (GVH) reaction became highly susceptible to MHV₃ injected 8 days after parental cell injection. Virus titer 3 days after injection was 2 logs higher in mice undergoing GVH than in controls. However F₁ hybrid mice resisted virus challenge when the first injection of virus was given 2 weeks before GVH induction. In addition, thymectomy also modified the behavior of resistant animals toward virus infection. It appears, therefore, that cell-mediated immune functions play an important role in resistance of mice to MHV₃.