Enhancement of depressed lymphokine activated killer cell activity in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) patients can be divided into two groups according to the degree of lymphokine activated killer (LAK) cell activity; a high LAK activity group (H-LAK-HCC) and a low LAK activity group (L-LAK-HCC). Interferon-gamma (IFN-gamma) production is severely defective in L-LAK-HCC but not defective in H-LAH-HCC. IFN-gamma production is suppressed with the addition of anti-Tac in dose dependent manner, though LAK activity is suppressed only in the presence of high concentration of anti-Tac. LAK activity is suppressed with the addition of anti-IFN-gamma, which is most prominent when the antibody is present during the first 12 hr of incubation. LAK generation is enhanced with the addition of recombinant IFN-gamma, which is most prominent when it is present during the first 12 hr of incubation. However, this enhancing effect is less prominent in L-LAK-HCC as compared to normals, liver cirrhosis, and H-LAK-HCC. This enhancement is regarded to depend on the presence of Leu7+ and Leu11+ subset, as this enhancement is abandoned and IFN-gamma production is inhibited when either of these subsets is deleted. These data suggest that IFN-gamma production and the participation of Leu7+ and Leu11+ subsets is important in sufficient LAK generation, and that poor IFN-gamma production and insufficient response to IFN-gamma may be the cause of severely defective LAK generation in L-LAK-HCC.