[Study of virus-associated lymphomas in primates using a model of malignant lymphoma of the baboon].

An outbreak of malignant lymphoma was registered in a population of hamadryas baboons. Animals inoculated with blood from patients with various forms of leukemia were planted into the stock 10 years ago. 218 out of 3219 animals have already died from lymphoma. The morphological pattern of horizontally-spreading lymphoma was similar to basic cell patterns of Hodgkin's and non-Hodgkin lymphoma in man. As far as the immunologic classification of tumor lymphoid cells is concerned, baboon lymphomas were of B-cell, T-cell and neither T- nor B-cell types. Xenotropic and ecotropic endogenous oncoviruses and lymphotropic herpesvirus of the baboon were isolated from cell cultures of healthy and sick animals. The said herpesvirus was closely related to a human one, both belonging to a family of primate lymphotropic herpesviruses. Plasma residue of the sick animals contained C-type oncovirus which immunologically differed from that of baboon endogenous oncovirus. Blood serum of nearly all sick baboons and those in the stock at high risk for lymphoma contained antibodies which entered into immunofluorescence reaction with antigens of HTLV virus-producing cells. Similar antibodies at a low titer concentration were identified only in individual lymphoma-free baboons in control. The relationship between HTLV virus and C-type oncovirus as well as their relevance to human hemoblastosis are being under study.