Preparation of stable target cells for anti-herpes simplex virus cytotoxic T lymphocytes

Using an avirulent strain of herpes simplex virus (HSV), SKa, and a methylcholanthrene induced sarcoma cell line, Meth A cells, we have developed a reliable target cell system for detection of cell-mediated cytotoxicity directed against HSV-infected cells. SKa-infection in Meth A produced no progeny virus but induced HSV-specific surface antigens as revealed by radioimmunoassay using 125I-labeled HSV antibody. Spontaneous release of 51Cr from the SKa-infected Meth A cells was no more than that from uninfected control cells but a strong spontaneous 51Cr release was produced in Meth A cells infected with KOS, a virulent strain which produced a progeny virus in Meth A and was lytic for the cells. When used as a target, SKa-infected Meth A cells could detect HSV-specific cytotoxicity by spleen and lymph node lymphocytes of mice immunized with SKa and KOS. This system also detected effector cytotoxic lymphocytes stimulated in vitro by mixed cultures of immune spleen cells and KOS-infected Meth A cells. Thus, the system should be valuable in studies of cell-mediated cytotoxicity directed against HSV-infected cells.