In vitro antitumor effect of LAK cells and alpha interferon in combination on tumor cell lines.

In intro antitumor effects of LAK cells and alpha-2b-Interferon (IFN) either alone or in combination were evaluated on NK resistant (K562) and NK sensitive (Namalwa, Raji) cell lines. Tumor cells were incubated with LAK cells for 4, 8 and 24 hours at a LAK: tumor cell ratio of 1:1, 10:1, 100:1, or with IFN for 48 and 96 h at the concentrations of 100, 1000, 10000, 100000 IU/ml. A clonogenic assay was utilised to enumerate residual cells after in vitro treatment. A positive correlation was found between tumor cell Willing and effector: target ratio, IFN concentrations and incubation times