The analysis of lymphocyte surface receptors recognized by wheat germ agglutinin for negative regulation of immune responses in cancer patients.

The population of peripheral blood lymphocytes expressing surface receptors for a lectin, wheat germ agglutinin (WGA), which has been shown to recognize the same receptors as the soluble immune suppressor factor (SISF) elaborated from suppressor cells on the lymphocyte surface, was analyzed by using fluorescein isothiocyanate-conjugated WGA on flow cytometry in cancer patients. It was found that the populations of WGA+ lymphocytes in cancer patients were significantly higher than those in either normal volunteers or patients with benign disease and increased with progress of the tumor. The populations decreased after treatment in patients who underwent curative resection of the tumor and in responders of immunochemotherapy but not in those who received non-curative surgery or in non-responders. It was suggested that the increase of receptors for SISF on the lymphocyte surface might play an important role in the negative regulation of immune responses in cancer patients and that WGA might be a useful parameter for immunosuppression.