Figure 2.

Cytotoxicity of NK cells was impaired by “Sialic acid-Siglec-7” interactions. (a, b) LDH release assay for quantifying the cytotoxicity of the peripheral NK cells (a) and NK-92MI (b) against Raji cells. The predesialylation of Raji cells was conducted by a neuraminidase treatment. The anti-Siglec-7 antibody (clone s7.7) blocking was performed before the coincubation of NK with Raji cells. (c) ELISA quantification of IFN-γ and granzyme B produced by NK-92MI-S7^high cells after an incubation with Raji cells for 1h at an E/T ratio of 5:1. The bars represent the standard error of three biological replicates. The significance was analyzed with the two-sided Student’s t test. Note, *, p < 0.05; **, p < 0.01; ***, p < 0.005; ****, p < 0.001.