Tumor coating solution

NK cell killing assays were performed on the xCELLigence MP platform (ACEA Biosciences). Specialized 96-well E-plates (ACEA Biosciences) were coated with tumor-coating solution (Agilent), and 4 × 10⁴ target K562 were plated in 100 μl of media. After the cell index reached 0.7, the effector cells were added at an effector cell to target cell (E:T) ratio of 1:1. NK cells were stimulated with 1 μg ml⁻¹ human IL-2 (PeproTech). As killing control, cells were treated with 2% Triton X-100 in water. Data were standardized and analyzed with RTCA 2.1 software (ACEA Biosciences). Supernatants were collected for granzyme B and perforin ELISA after 90 h.

T cell killing assays were performed on the XCelligence MP platform (ACEA BioSciences, San Diego, CA.). Specialized 96-well E-plates (ACEA BioSciences) were coated with tumor coating solution (Agilent) and 4 × 10⁴ target Nalm6 cells or Daudi cells were plated in 100 μl cell-specific media. After the Cell Index reached 0.7, effector T cells were added at different effector cell to target cell (E:T) ratio of 0.125:1 to 7:1. For serial killing XCelligence assays, effector T cells were pooled after 24 h, counted and plated back on a different plate with target cells 4 times in total. As killing control, cells were treated with 2% TritonX100 or media only was added. Data were standardized and analyzed with the RTCA software (ACEA).