6 Human Papovaviruses

Abstract

In preceding chapters we discussed the molecular biology of polyoma virus and SV40. In 1971 two human papovaviruses were isolated; each was designated by the initials of the person from whom it was obtained: BK virus (BKV) and JC virus (JCV). These two viruses proved to be related to SV40, and with the designations BKV and JCV they have been recognized by the International Committee on Taxonomy of Viruses as new species of the genus Polyomavirus (Fenner 1976). Since 1971 these viruses have been isolated from several more people and usually have been given individual designations (see Table 6.1).

THE PROTOTYPE VIRUSES
BKV was isolated by Gardner et al. (1971). Routine cytological examination of urine sediments from a patient receiving immunosuppressive therapy following kidney transplantation revealed transitional epithelial cells with enlarged, inclusion-bearing nuclei. Electron microscopic examination of thin sections of the exfoliated cells showed the presence of intranuclear, viruslike particles; free virions of a size and structure typical of polyoma virus were observed in negatively stained urine sediments. The virus was isolated in VERO cells. In the electron microscope, the cultured virions were indistinguishable from those of polyoma virus. The virus hemagglutinated human and guinea pig erythrocytes, and, in serological tests, it reacted weakly with antisera against SV40 but not at all with antisera against polyoma virus or human papilloma virus. Gardner and her colleagues concluded that BKV was a new human virus of the polyoma-SV40 group.

JCV (Padgett et al. 1971) was isolated from diseased brain tissue obtained at...