Activation of an endogenous mouse type C virus by ultraviolet-irradiated herpes simplex virus types 1 and 2

Infection of BALB/c mouse cells with UV-irradiated herpes simplex virus (HSV) types 1 and 2 resulted in activation of a xenotropic type C virus detected by infectious center formation in permissive rat cells. The levels of type C virus activated by HSV were related to the UV dose and the multiplicity of infection used. The ability of HSV to activate type C virus was eliminated by heat-inactivation and by neutralization with specific antiserum against HSV, but was not affected by purification or treatment with DNase and RNase. Maximum levels of type C virus in the cells and medium were observed within 1 day after HSV infection, and the levels returned to control cell values within 3-4 days. The possible significance of these findings with respect to the putative oncogenic potential of HSV is discussed.