Fig. 2
CR Abs induce human neutrophils to secrete IL-8 and MPO in the presence of RBD. (A, B) Isolated human neutrophils (2 × 106 cells/mL, 0.3 mL/test) were treated with the recombinant RBD protein in the presence or absence of the indicated antibodies (mAb 127 or cmIgG) for different time points (1, 3, 6, and 24 h). (C, D) Neutrophils were cotreated with 10 μg/mL RBD recombinant protein and mAb 127 or cmIgG at different concentrations (2.5, 5, or 10 μg/mL). (E, F) Neutrophils were stimulated with the recombinant RBD protein in the presence or absence of the indicated antibodies (mAbs 127, LGSV201, cmIgG, or anti-ACE2) for 24 h. The supernatants from these experiments were collected, and IL-8 and MPO levels were quantified using ELISA kits. The averages of triplicate cultures ± SD are shown. Statistical significance was calculated using one-way ANOVA and Tukey’s post hoc test; P values were displayed, and for values less than 0.0001, they were represented as ****