Tumor necrosis factor alpha is not a pathogenic determinant in acute lethal encephalitis induced by a highly neurovirulent strain of mouse hepatitis virus.

To investigate the role of tumor necrosis factor alpha (TNFalpha) in the pathogenesis of acute viral encephalitis, TNFalpha-deficient mice were infected with a highly neurovirulent strain of mouse hepatitis virus, JHM, and compared with JHM-infected C57BL/6 mice as controls. All the JHM-infected mice had succumbed to infection by 6 days postinfection. The virus replication kinetics, histopathological changes and mRNA expression levels of proinflammatory cytokines in the brain did not differ between TNFalpha-deficient and control C57BL/6 mice. These results suggest that TNFalpha is not a pathogenic determinant in JHM-induced acute lethal encephalitis.