FcγR-Ig blocks the macrophage mediated antibody-coated endothelial cell death.

<p><b>(A)</b> RAW 264.7 cells were co-cultured with HUVECs coated with anti-human fibronectin Ab or HUVECs alone in the presence or absence of CD16A-Ig and CD32A-Ig at 37°C. <b>(A)</b> The cells were analyzed after 2hr for binding of RAW264.7 cells with HUVECs using plate inversion method. <b>(B)</b> After 8hr, the HUVECs viability was analyzed using CellTiter-Blue Assay method. <b>(C)</b> After 12hr caspase-3 assay was carried out by calorimetric method. Blocking mAbs (2.4G2), CD16A-Ig, and CD32A-Ig were pre-incubated for 1 hr at 4°C and then continuously present during their incubation at 37°C. In all the experiments RAW 264.7 cells pretreated with 2.4G2 mAb, antigen alone, antibody alone, HUVEC treated with medium alone served as controls. Data shown are the average of three individual experiments; each experiment was carried in triplicate. P value < 0.05 considered as significant (*) and P< .005 as highly significant (**), NS: non-significant.