[Interferon-induced protection of renal cell cancer cell lines to lymphokine-activated killer (LAK) cells and effect of acid treatment on their susceptibility. Its relevance to expression of major histocompatibility complex class I antigens on tumor cells].

Renal cell cancer (RCC) cell lines, ACHN and KRC/Y, with or without exposure to interferons (IFNs), were examined for their susceptibility to lymphokine-activated killer (LAK) cells in relation to modulation of major histocompatibility complex (MHC) class I antigens on tumor cells. Flow cytometric analysis demonstrated constitutional expression of class I antigen on both cell lines, which was enhanced by IFN-alpha and -gamma, and was reduced by acid treatment at pH 3. A 4-h 51Cr-release cytotoxicity assay demonstrated that pretreatment of both cell lines with IFN-alpha and -gamma decreased their susceptibility to LAK cells. Although an inverse correlation between class I antigen expression and susceptibility to LAK cells has been reported by others, IFN and acid treatment demonstrated that the degree of class I antigen expression did not correlate with the susceptibility to LAK cells. These results suggest that clinically administered IFNs might induce protection of RCC to LAK cells, and that decrease of susceptibility might depend upon a mechanism different from the enhancement of class I antigens which is frequently expressed on RCC.