Induction of B-cell lymphomas in athymic NIH Swiss nu/nu mice.

A B-cell lymphoma was induced in athymic NIH Swiss nu/nu mice by challenging the animals with NIH3T3 cells, previously transfected with a recombinant DNA carrying a human oncogene hhcM, ligated to an SV40 promoter with a neomycin-resistance marker. The gross pathology of the tumor-bearing animal revealed generalized lymphadenopathy and the histopathology indicated widespread infiltration of lymphocytes into organs, such as brain, liver, kidney and lung, in addition to the lymphoid tissues and spleen; the appearance was consistent with diffuse histiocytic lymphoma. Direct immunofluorescence assays with specific typing anti-sera on live cells prepared from spleen and various lymph nodes in short-term culture, suggested the cells were B-cells. This B-cell lymphoma provides an experimental model, not only for studying possible oncogene activation but also for studying the various interactions involved in signal transduction essential for the activation of B-cell proliferation and differentiation.