Keyhole limpet hemocyanine can enhance the natural killer activity of patients with transitional cell carcinoma of the bladder

Abstract

It has been shown that natural killer (NK) cells are involved in the immunosurveillance of tumors. In patients with transitional cell carcinoma (TCC) of the bladder, there is a negative correlation between the levels of NK activity in peripheral blood mononuclear cells (PBMNCs) and both the clinical evolution and the pathological stages of the disease. We have investigated the immunoregulatory effect of keyhole limpet hemocyanin (KLH) on the NK activity of patients with TCC of the bladder. We found that KLH enhances the cytotoxic activity of PBMNC from patients with superficial TCC against NK-sensitive target cells in a time-dependent manner. This KLH-enhanced cytotoxicity is not directed against NK-resistant target cells. However, KLH fails to normalize the depressed NK activity of PBMNCs from patients with infiltrative TCC. The present in vitro studies suggest that this immunoregulatory effect of KLH on NK cytotoxicity may be implicated in its therapeutic effect on superficial TCC of the bladder.