Meningoencephalitis and demyelination are pathologic manifestations of primary polyomavirus infection in immunosuppressed rhesus monkeys

The human polyomavirus JC (JCV) is the etiologic agent of progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the CNS that occurs in immunosuppressed individuals. Because polyomavirus-induced CNS pathology usually occurs as a result of the reactivation of latent virus, little is known about the disease manifestations of a primary polyomavirus-induced disease in man. To model such a primary infection, SV40-negative rhesus monkeys were immunosuppressed by infection with the virus SHIV-89.6P and then superinfected with the polyomavirus SV40. The animals developed CNS pathology characterized by both demyelination and meningoencephalitis. This observation suggests that a primary polyomavirus infection can be associated with an inflammatory CNS process. These data shed new light on the pathogenic mechanisms of primate polyomaviruses in the immunocompromised host.