Stimulation of host DNA synthesis and induction of early antigens by ultraviolet light irradiated human cytomegalovirus.

The ultraviolet (UV-)sensitivity of the human cytomegalovirus (HCMV) genes coding for very early complement fixing and early antigens in human embryonic fibroblasts (HEF) and mouse embryonic fibroblasts (MEF) and the relation of these genes to the ability of the virus to stimulate host cell DNA synthesis were investigated. After 14 minutes of UV-irradiation of the virus inoculum only the very early complement fixing nuclear antigen (CMNA) developed in the HEF cells and only the early cytoplasmic antigen(s) was present in the MEF. In both HEF and MEF, host cell DNA synthesis was stimulated. We conclude that the ability of HCMV to stimulate host DNA synthesis is an early function of the viral genome and shows a high resistance to UV-irradiation. There is no direct correlation, however, between the ability of the virus to stimulate host cell DNA synthesis and the genes which code for the CMNA or for early cytoplasmic antigens.