Interaction of simian virus 40 with human glioma cells.

A human oligo-astrocytoma grade II was successfully grown in tissue culture. Using glial fibrillary acidic protein (GFAP) as an astrocytic marker two main cell types could be differentiated: GFAP-positive astrocytes and GFAP-negative oligodendrocytes. After transformation by SV40 about 90% of the tumor cells expressed SV40 T-antigen as detected by indirect immunofluorescence. The percentage of viral capsid (V-)antigen was much lower; it was only found in oligodendrocytes. Six passages after transformation the oligodendrocytes were eliminated due to lytic viral infection. By double immunofluorescence with anti-GFAP as a cell marker and anti-T as a viral marker the remaining cell type was identified as transformed astrocytes. These data suggest a different susceptibility of oligodendrocytes and astrocytes, respectively, to transformation by SV40. While the oligodendrocytes permit the production of infectious virus, the astrocytes are more sensitive to transformation. The evident correlation to human progressive multifocal leukoencephalopathy will be discussed.