Mice bearing TEPC-183, an
immunoglobulin M(kappa)-secreting
plasmacytoma, exhibit severe suppression of their immune responses to both thymus-dependent and
thymus-independent antigens, 2,4-dinitrophenyl, and the type 3 pneumococcal
polysaccharide SSS-III. This immunosuppression is not lifted by
splenectomy of the
tumor-bearing mice or prevented by removal of the spleen prior to
tumor injection. On the contrary,
splenectomy either before or after
tumor implantation further accentuates the immunosuppressed state of
tumor bearers and even depresses the immune response of normal mice. A secondary immune response of normal mice 34 to 51 days after
splenectomy is still reduced. Thus, spleen cells may play a dual role. While
splenectomy may remove a source of suppressor cells in
tumor-bearing mice, it also eliminates a major source of antibody-producing cells and results in reduced immune responses of normal and TEPC-183-bearing mice. These findings have clinical relevance since
splenectomy is used as a therapeutic and diagnostic procedure in neoplastic
lymphoproliferative disorders.