Immune cytolysis of human renal carcinoma mediated by xenogeneic immune ribonucleic acid.

With a microcytotoxicity assay it was shown that normal, non-immune human lymphocytes were converted to effector cells specifically cytotoxic to human renal carcinoma cells after incubation with xenogeneic immune ribonucleic acids. The ribonucleic acid was extracted from the lymphoid tissues of sheep that had been immunized with human renal carcinoma tissue. Lymphocytes incubated without ribonucleic acid from or with ribonucleic acid sheep immunized with Freund's adjuvant alone did not increase cytotoxicity. Immunotherapy with immune ribonucleic acid increased cytotoxic activity of lymphocytes from a patient with metastatic renal carcinoma. The microcytotoxicity assay may be a useful method to assessing the cellular immune response in patients receiving immunotherapy and seems to correlate with their clinical course.