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anti-RhD antibodies modulate NK cell activity
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Figure 6. The anti-RhD drug KamRho induces killing of immature den- dritic cells by natural killer cells. (A) Cytotoxicity assay. 35S-labeled immature dendritic cells (iDC) were incubated with activated natural killer (NK) cells and different polyclonal antibodies (intravenous immunoglobulin [IVIG] or KamRho). The effector to target (E:T) ratio is indicated on the x-axis. One representative experiment is shown out of five performed. **P<0.01, ***P< 0.001; ANOVA with Tukey’s HSD post-hoc test. Error bars represent standard deviation of triplicates. (B) Cytotoxicity assay was performed as in (A), with 35S-labeled mature DC (mDC) cells used as targets. One representative experiment is shown out of two performed. *P<0.05, **P<0.01; ***P<0.001; ANOVA with Tukey’s HSD post-hoc test. Error bars represent standard deviation of triplicates. (C) Cytotoxicity assay was performed as in (A), with 35S- labeled iDC cells as targets, at an E:T ratio of 50:1. The assay was per- formed with pre-blocking of CD16 on NK cells using mouse IgG2a. One representative experiment is shown out of two performed. ns: non-sig- nificant; Student's t-test. Error bars represent standard deviation of triplicates. (D) Cytotoxicity assay. B lymphocytes, 721.221, or K562 cells were 35S-labeled and then incubated with activated NK cells and different polyclonal antibodies (IVIG or KamRho). The E:T ratio is 50:1 for B lymphocytes and 5:1 for 721.221 and K562 cells. One represen- tative experiment is shown out of five performed with 721.221 and K562 cells, and two performed with B lymphocytes. ns: non-signifi- cant; Student's t-test. Error bars represent the standard deviation of triplicates.
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haematologica | 2021; 106(7)
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