Viruses and renal carcinoma of Rana pipiens. XV. The presence of virus-associated membrane antigen(s) on Lucké tumor cells.

Virus-specific antigens were detected in Lucké tumor cells by indirect immunofluorescence using antiserum prepared against Lucké herpesvirus. Intracellular fluorescence, both cytoplasmic and nuclear, was observed only in acetone:methanol-fixed tumor cells that contained herpesvirus detected by electron microscopy. The number of positive cells correlated well with the number of cells containing virus. In contrast, both virus-containing and virus-free cells exhibited membrane fluorescence when viable unfixed tumor cells were tested. A striking reduction in the number of membrane fluorescent cells was observed with an increase in the length of time that tumor cells were in primary culture. No reaction was observed with a variety of normal R. pipiens cells. Absorption of the antiserum with normal frog kidney tissue had no effect on the number of positive cells whereas absorption with virus-free tumor reduced the reaction; absorption with virus-containing tumor eliminated it. These findings provide the first demonstration that the Lucké herpesvirus genome resident in virus-free tumor cells expresses a virus-associated membrane antigen(s).