The tumor specific immune response of experimental active-specific immunotherapy.

Evidence for augmentation of antigenic recognition was investigated by measuring antigen-specific lymphocyte stimulation in animals which were minimally immunized with Con A-modified tumor cells. Comparison of lymphocyte stimulation response was made to animals immunized with unmodified tumor cells or sham immunization. Markedly heightened, tritiated Thymidine incorporation was observed in the lymph node cells from animals immunized with Concanavalin A-modified tumor cells, while minimal response was observed in control hosts. These preliminary findings imply that Con A-modified tumor cell immunotherapy may work by augmenting the host's capacity to recognized minimal differences in immunogenicity between tumor cells and the normal cells or origin. This modulation of the immune response may be a key factor in the success of active-specific immunotherapy.