Surface Iminunoglobulins of Circulating Lymphocytes in Mouse Plasmacytoma . H . The

Circulating lymphocytes of plasmacytoma-carrying BALB/c mice were found to lose their normal surface immunoglobulins; in their place surface structures characteristic of the specific plasmacytoma globulin were demonstrated by the immunocytoadhesion technique. These changes were experimentally reproduced by the incubation of normal BALB/c lymphocytes with an RNA preparation obtained by hot phenol extraction from the excised plasmacytomas. RNA treated by RNAse was inactive, while DNAse or trypsin had no inactivating effect. Lymphocytes, killed with heat or KCN, underwent no alteration of surface receptors following incubation with the tumor RNA. Plasmacytoma RNA, injected intraperitoneally into normal mice, also altered the reactivity of circulating lymphocytes. These observations suggest the possibility that this effect contributes to the functional impairment of the immune system in this disease. I N THE PRECEDING COMMUNICATION’ we reported that in BALB/c mice with plasmacytoma the proportion of circulating lymphocytes having normal immunoglobulin determinants on their surface diminished with the progression of the disease. Concomitant with this development, lymphocytes with surface structures characteristic of the plasmacytoma immunoglobulins were demonstrable. Absorption of these plasmacytoma globulins from the surrounding plasma was excluded by appropriate studies. The possibility was considered that this alteration was brought about by a product of the tumor other than the immunoglobulin itself. It has been known for more than 10 yr that RNA extracts of antibodyproducing lymphocytes are capable of transferring the information of antibody specificity to uncommitted cells.29 Recently, the studies of Bell and Dray’#{176}”