Overexpression of Ki-67 and Cyclins A and B1 in JC Virus-infected Cells of Progressive Multifocal Leukoencephalopathy

    loading  Checking for direct PDF access through Ovid

Abstract

Abstract.

Both SV40 and JC virus (JCV) appropriate the host cell replicative machinery to attend to their own reproductive needs. SV40 large T antigen is able to induce the expression of cyclins A, Bl, and E (but not of cylin Dl) in transfected diploid cells. Whether JCV infection influences cyclin expression in a similar fashion in the setting of progressive multifocal leukoencephalopathy (PML) remains unknown. Brain lesions from 7 PML cases (4 autopsies and 3 biopsies) were immunohistochemically investigated for the expression of Ki-67 and cyclins A, Bl, and Dl. All 7 cases showed strong positivity for Ki-67 and cyclins A and B1 in JCV-infected oligodendrocytes and astrocytes, the nuclear immunolocalization of cyclin A being in strong contrast to the cytoplasmic distribution of cyclin Bl. No immunostaining for cyclin Dl was obtained in any of the 7 cases. These findings suggest that JCV infection is associated with overexpression of Ki-67 and cyclins A and B1 in PML host glial cells. Since cyclin changes in JCV-infected cells recapitulate SV40 T antigen-associated cyclin fluctuations, it appears reasonable to think that JCV T antigen shares some of the previously described capabilities of SV40 T antigen to alter cyclin expression for the sake of viral replication.

Related Topics

    loading  Loading Related Articles