[NK cell activity and inhibition by anti-HLA monoclonal antibodies].

The authors followed the effect of anti-HLA class I and II monoclonal antibodies on cytotoxic activity of human NK cells. The mAb 18/5, 23/9 and beta 2m (anti-HLA class I) as well as mAb 20/DR, 30/DR, 13/DP and FB6/DP (anti-HLA class II) were used. Both groups of the antibodies were either tested directly during the cytotoxic test, or NK cells were pre-incubated with them. The application of the antibodies results in an inhibition of NK cell activity by the average of one third. However, the pre-incubation of NK cells with the mAb has not been so unambiguous. On the other hand, the application of anti-HLA class I and class II mAb had no effect on the interaction of NK cells with their target cells. We can conclude that HLA molecules might play a role in the late stages of the cytolytic mechanism of NK cells. (Fig. 1, Tab. 2, Ref. 21.)