STUDIES OF LYMPHOCYTE STIMULATION TO TUMOR-ASSOCIATED ANTIGEN .1. UPTAKE OF LYMPHOCYTE PROTEIN AND NUCLEIC-ACID PRECURSORS IN RESPONSE TO AUTOLOGOUS AND ALLOGENEIC TUMOR-ASSOCIATED ANTIGEN SOLUBILIZED FROM HUMAN-TUMORS

Lymphocyte stimulation to 3 M KCl extracts of fresh human tumors was studied by measuring the incorporation of 3H-labeled protein and nucleic acid precursors. Lymphocytes from cancer patients and normal donors were incubated with autologous and allogeneic extracts. Duplicate lymphocyte cultures were labeled with 3H-leucine (3H-Leu), 3H-uridine (3H-Udr), or 3H-thymidine (3H-Tdr). All patients were sensitized to keyhole limpet hemocyanin (KLH) prior to testing. Of the 29 cancer patients tested, many demonstrated significant uptake of 3H-Udr (90%) and 3H-Leu (62%), but not 3H-Tdr (7%) in response to soluble tumor extracts. However, most patients demonstrated uptake of all three precursors in response to KLH. Lymphocytes from cancer patients did not undergo morphologic blast cell transformation in the presence of tumor extracts. Significant incorporation of 3H-Leu and 3H-Udr was seen after 24-48 h of incubation, while significant 3H-Tdr incorporation was not detected until day 5. Stimulation by KLH was significantly greater for all isotope precursors than stimulation in response to tumor extracts. Responses of lymphocytes from normal donors to tumor extracts were noted, although they occurred less frequently than in lymphocytes from cancer patients. Lymphocytes from cancer patients incorporated 3H-Leu and 3H-Udr, but only rarely incorporated 3H-Tdr in response to 3 M KCl extracts of fresh tumors. © 1979 Springer-Verlag.