Fig. 4

Anti-Dsg3 autoantibodies detected in healthy blood donors do not lead to Dsg3 internalization in vitro. HaCaT cells were incubated with IgG from healthy individuals (NH-IgG), IgG from a pemphigus vulgaris patient (PV-IgG) or with Dsg3-positive plasma samples from healthy blood donors (samples #1382, #3167 and #9607), as well as with a Dsg3-negative sample (sample #4025). For all experimental conditions (n = 3), the IgG concentration was 1 mg/ml (with the exception of the diluted PV-IgG samples). While NH-IgG and 4025 did not induce Dsg3 internalization, PV-IgG at 1:1 and 1:100 dilutions led to Dsg3 internalization. At low dilutions, PV-IgG and all tested Dsg3-positive samples from healthy blood donors did not show any effects on Dsg3 internalization