STUDIES ON HOMOTRANSPLANTABLE LYMPHOMAS IN HAMSTERS

Abstract

Further experiments with 2 homotransplantable lymphomas are reported. Each tumor provoked a different morphological response in the recipients'' lymphoid tissues. One of the lymphomas, which metastasizes widely, stimulated marked plasmacytosis in the draining nodes; the other, which does not metastaslze, induced a massive proliferation of sinus histiocytes and interfollicular blast cells. Immunofluorescent staining in tissues from hamsters bearing subcutaneous grafts of the 2 tumors was compared, using a conjugated rabbit anti-hamster gamma-globulin serum. The metastasizing tumor stimulates a marked increase in specifically stained lymphoid cells in the medullary cords of the draining nodes and in the spleen; most of the tumor cells themselves are also coated with gamma-globulin. The nonmetastasizing lymphoma evokes a different response with a small increase in stained cells in the regional nodes, moderately increased staining in the spleen, but no staining of the tumor cells. The metastasizing lymphoma initiates a predominantly humoral immune response. The nonmetastasizing lymphoma is associated with a more complex reaction: cellular mechanisms predominate but humoral components, principally derived from the spleen, are also involved, which may be specific enhancing antibodies. General implications are considered.