Immunosuppressive Effect of Friend’s Mouse Leukaemia and Anti-Thymocyte Serum on Herpes Simplex Virus Infection in Mice

Abstract

Clinical observations have revealed that infection with herpes viruses, such as herpes simplex virus, herpes zoster virus, varicella virus or cytomegalovirus can produce severe complications in patients at the terminal stage of neoplastic diseases, especially leukemias, or in those receiving immunosuppressive treatment following organ transplantation. From 611 reported clinical cases receiving organ transplants 125 developed complication from viral infections (Munk and Runnebaum, 1970). The majority of these complications were caused by herpes viruses. Because of these observations we investigated the immunosuppressive activity of Friend’s mouse leukaemia virus (FLV) infection and antithymocyte serum (ATS) on herpes simplex virus (HSV) infection in mice. Ceglowski and Friedman (1968 a, b, 1969, 1970) and Friedman and Ceglowski (1968, 1971) conducted an extensive study of the immunosuppressive effect of FLThese*V. authors observed a reduction in antibody formation in FLV infected animals injected with sheep erythrocytes and E. coli, and concluded that FLV reduces the number of immuno competent lymphocytes. We developed this system further in order to analyze the mechanisms of reduced immune reaction to HSV infections. In addition, we applied ATS as another immunosuppressive factor. In the first series of experiments we investigated the reduction of resistance to HSV infection in mice previously infected with FLResistance*V. to infection was defined in terms of LD50 for mice receiving a standard HSV suspension.