Analysis of cytolytical activity of human polyclonal NK cells on target melanoma cells. Blocking of HLA-G1 on transfectants with anti-human HLA-G (87G) restored specific lysis. Target cells: M8 cell line transfected with empty vector (column 1) and with HLA-G1 cDNA (columns 2-6).Blocking antibodies: Column 1-2: noneColumn 3: Isotype mouse IgG2a controlColumn 4: anti-human HLA-G (87G) purifiedColumn 5: anti-human HLA-G (87G) F(ab')2 fragmentColumn 6: anti-human HLA-G (MEM-G/9)