Figure 3.

Tim-3 blockade enhanced NK cell-mediated natural cytotoxicity against human MM cell lines. exNK, NKL, NK-92 cells were used as effector (E) cells and human MM cell lines were used as target (T) cells. The E:T ratios of exNK, NKL, NK-92 cells were 1:1, 5:1, 1:1, respectively. (A, B) Cytotoxicity activity of NK cells was tested by PKH26/Annexin-V stain. The cytotoxicity of NK cells was determined by the percentage of apoptotic MM cells at the indicated E:T ratios after pre-incubation with 10 μg/ml anti-Tim-3 antibodies. (C, D) The degranulation level of NK cells was detected by CD107 degranulation assay. The dot plots illustrating CD107a surface expression on the NK cells after stimulation by the target cell lines, respectively. One representative of at least three independent experiments. Data shown were mean ± SD of at least three independent experiments. *P < 0.05, **P < 0.01 versus control NK cells.