ASCITIC GROWTH OF A T-CELL LYMPHOMA IN MICE ALTERS THE HUMORAL AND CELLULAR IMMUNE-RESPONSE TO EXOGENOUS ANTIGENS

The effect of the ascitic growth of Dalton's lymphoma (DL), a T cell l ymphoma, on the immune responses of the host mice to exogenous antigen s, with respect to the humoral response, delayed-type hypersensitivity (DTH) response and the antigen-presenting ability of macrophages was investigated. The humoral immune response to sheep red blood cells (SR BC) as well as the antigen-presenting ability of macrophages (with key hole limpet hemocyanin as the standard antigen) in the DL-bearing mice were consistently higher than in the normal mice, although the magnit ude showed a decline during later tumor stages. However, the DTH respo nse to SRBC was suppressed in the DL-bearing mice compared with the re sponse in the normal mice. The possible mechanisms are discussed. In v ivo administration of FK565, a synthetic biological response modifier, enhanced the humoral immune response as well as the antigen-presentin g ability of the macrophages in the normal and early DL-bearing mice, whereas these immune responses n the later tumor-bearing animals were found to be nonresponsive to FK565 treatment. In contrast, the DTH res ponse in the normal as well as in the DL-bearing mice was suppressed o n FK565 administration. This is the first study of its kind regarding the effect of the ascitic growth of any T cell lymphoma on various asp ects of the immune response to exogenous antigens and the correlation thereof with an immunomodulator.