Figure 3.

Anti-LLT1 antibody dose-dependent treatment on TNBC MDA-MB-231 demonstrates enhanced killing by primary NK cells. TNBC cell line MDA-MB-231 was treated with either anti-human LLT1 antibodies (αLLT1) or isotype control antibodies. MDA-MB-231 cells were treated with anti-LLT1 antibodies at four different concentrations. There is greatest lysis of TNBCs when treated with anti-LLT1 antibodies at 1 µg per well compared to other concentrations and isotype IgG control (P = 0.08, student paired t-test). Cells were labeled with ⁵¹Cr and then were co-incubated with primary NK cells isolated from PBMCs derived from whole blood of healthy volunteers at effector-to-target ratios (NK-to-5000 TNBCs) of 25:1, 5:1, and 1:1 for 3.5 hours. Specific lysis of labeled cells was subsequently quantified and calculated. This assay was performed in triplicates and error bars indicate standard deviations.