Induction of lymphoma in athymic mice: a model for study of the human disease.

A murine lymphoma, designated L1, was produced in immunologically deficient nude mice after chronic antigenic stimulation by infection with the pinworms Aspiculuris tetraptera and Syphacia obvelata. In vivo, L1 involves primarily the spleen and lymph nodes, with infiltration of liver, kidney, and bone marrow also observed. It is characterized by large clusters of B cells and null cells, and by rare T cells. The lymphoma cells express murine leukemia virus antigens (gp70 and p30) on the surface. L1 can be passaged successfully both in vivo and in vitro. The lymphoblasts that proliferate in vitro are null, but injecton back into the mouse produces a similar pattern of B cells, null cells, and occasional T cells as seen in the mouse-to-mouse transfers. Infectious viruses have been isolated from L1 cells and from tissue culture supernates and have been identified as a B-tropic murine leukemia virus and a xenotropic virus. The possibilities of this model for studying the etiology of human lymphoma are discussed.