Figure 3.

Interdependency of signaling pathways activated by pemphigus autoantibodies. Immunoblots of cell monolayers pretreated with either pharmacological inhibitors for 1 h or BAPTA-AM for 4 h followed by IgG fractions for 30 min. (A) EGFR activity was reduced after Src inhibition by PP2 (n ≥ 6, *p ≤ 0.05, two-way ANOVA) (B) After inhibition of EGFR by Erlotinib, ERK phosphorylation was significantly reduced in cells treated with PF-IgG. (n ≥ 6, p ≤ 0.05, two-way ANOVA) (C) Ca²⁺ influx was measured by Fura-2 ratiometric fluorescence imaging and found to be independent of EGFR (n = 3, *p ≤ 0.05, two-way ANOVA) Representative graph with experimental setup on the left and analysis at t = 120 s on the right. Dotted line indicates application of the respective IgG fraction.