Induction of encephalitis in SJL mice by intranasal infection with herpes simplex virus type 1: a possible model of herpes simplex encephalitis in humans.

Herpes simplex encephalitis (HSE) is characterized by focal lesions of hemorrhage and necrosis, primarily in the inferior temporal lobe. Since immunosuppressed patients with HSE lack the focal inflammatory changes and temporal lobe localization, it has been suggested that the immune system participates in the pathogenesis of HSE. Evaluation of this hypothesis has been impeded by the lack of an immunologically defined animal model that resembles the human disease. Toward this end, 10 strains of inbred mice were infected intranasally with a neurovirulent clinical isolate of herpes simplex virus type 1. Most mice died without localizing signs of disease in the central nervous system. However, a significant number of SJL mice had a pattern of encephalitis highly reminiscent of that described in humans. To our knowledge, this is the first murine model that faithfully mimics this human disease, and thus it affords the opportunity to study the immunopathogenesis of HSE.