Development of a model for cytomegalovirus infection of oligodendrocytes

The well-characterized human oligodendroglioma (HOG) cell line, cells of which resemble immature oligodendrocytes, was used to investigate the level of permissiveness to human cytomegalovirus (CMV) infection. Expression of CMV genes was incomplete following exposure of HOG cells to CMV, in contrast with results observed with the astroglioma cell line U373-MG (used as a positive control). However, treatment with phorbol 12-myristate 13-acetate (PMA) or with dibutryl cAMP (dbcAMP) plus the phosphatase inhibitor 1-isobutyl-3,3-methyl xanthine (IBMX) rendered the HOG cells fully permissive to CMV; down-regulation of HLA class I and production of virions were only observed under these conditions. In contrast to the findings seen with the HOG cell line, treatment of U373-MG cells with dbcAMP/IBMX or PMA did not interfere with CMV-induced down-regulation of HLA class I. However, these chemical stimulators reduced virus production in U373-MG cells by 30 and 70%, respectively.