1984 Volume 75 Issue 7 Pages 1124-1133
The aim of this study is to investigate the mechanism of both the effects of a streptococcal preparation (OK 432) on augmentation of human natural killer (NK) cell activity of peripheral blood lymphocytes (PBL) and antiproliferative activity of OK 432 for cell lines derived from urinary tract tumors.
PBL were isolated from healthy donor and patients with urogenital disorder, and were, then, cultured with OK 432 or supernatants from 15-hr OK 432-stimulated PBL cultures (sample medium). Cell lines derived from carcinoma of the prostate (DU 145 and PC 3) and kidney (KU 2) were used as the target cells. K 562 cells, well known for their high susceptibility to NK cell-mediated cytolysis, were also used as the control target. NK cell activity was tested by a short-term 51Cr-release assay.
To assess the possibility of OK 432 inducing interferons (IFNs), the culture medium of PBL pretreated with OK 432 was analyzed for anti-viral activity. Determination of the type of IFN induced by OK 432 was made by both acidification (pH 2.0) and neutralization of sample midium. IFN-titer in the medium was neutralized by anti-IFN-α or-β antibody.
Antiproliferative activity of OK 432 was evaluated by examing the growth curves of KU 2 and DU 145 cells following treatment of these cells with OK 432, IFN-α or sample medium.
The present study demonstrates the following: (1) NK cell activity is significantly enhanced by treatment of PBL with OK 432; (2) OK 432 exerts direct antiproliferative effect on cell lines tested; (3) most of IFNs induced by OK 432 are IFN-α and-γ; (4) IFN which is found to be chiefly responsible for the enhancement of NK cell activity elicited by OK 432 treatment is IFN-γ and (5) the sample medium comprising both OK 432 and IFNs has greater antiproliferative effect than OK 432 medium alone.
