Abstract
A large proportion (24-45%) of circulating lymphocytes of normal BALB/c mice was found to have surface immunoglobulins with polyclonal characteristics. Following implantation with plasmacytoma, the percentage of these normal receptor-carrying lymphocytes (RCL) was found to decrease. Concomitant with the growth of the tumors, the proportion of lymphocytes having receptors with the structural properties of the specific plasmacytoma globulin gradually increased. The antisera with which these new surface structures were demonstrated were specific for the variable portion of the Fab fragment, the idiotypic determinant of the plasmacytoma globulin. These antisera were not only raised in rabbits and rendered antiidiotypic by appropriate absorptions, but also in BALB/c mice. Evidence is presented that this alteration of receptors on the normal lymphocytes depends on the presence of tumor cells and is not caused by nonspecific absorption of the immunoglobulins to the lymphocytes.
