INTERFERON-BETA ENHANCES THE NATURAL-KILLER ACTIVITY OF PATIENTS WITHBLADDER-CARCINOMA

We have investigated the effect of interferon alpha (LNF beta) on the natural killer (NK) cytotoxic activity of peripheral blood mononuclear cells (PBMC) from patients with superficial and infiltrative transiti onal-cell carcinoma of the bladder (TCC) against both NK-sensitive and NK-resistant target cells. The normal NK activity found in PBMC from these patients can be significantly enhanced by short-term incubation (18 h) with INF beta (P <0.05). The depressed NK cytotoxic activity fo und in PBMC from patients with infiltrative TCC can also be significan tly enhanced, but not normalized, by short-term incubation with LNF be ta (P <0.05). In kinetic studies we found that the maximal levels of t he INF beta-promoted cytotoxic activity against NK-sensitive and again st NK-resistant target cells in PBMC from TCC patients were reached af ter 18 h of culture. Short-term-INF beta-incubated PBMC from patients with TCC of the bladder also showed marked cytotoxic activity against NK-resistant target cells. The effector cells of the INF beta-induced cytotoxic activity in PBMC from patients with TCC were CD16+ CD3- NK c ells. This cytotoxic inducer effect of INF beta synergized with that o f interleukin-2. In conclusion, INF beta can enhance the NK activity o f PMBC from patients with TCC of the bladder.