Inhibition of Ca2+ flux is protective
against PV-IgG-induced pathogenic effects in vitro
PV-IgG caused loss of keratinocyte adhesion in dispase-based
dissociation assays. Treatment with inhibitors against PI4K ,PLC , IP3R or CRAC added 1 h before PV-IgG effectively
blocked cell monolayer fragmentation after 2 h and 24 h. After 24 h,
inhibition of PLC was the most effective and even reduced the
effect of AK23 (Figure 2a-d/S2a-d).
The role of Ca2+ signalling for PV-IgG-mediated
effects on DSG 1 and DSG 3 localization, keratin retraction
and reorganization of cortical actin was assessed by immunostaining and
F-actin staining. After 24 h of PV-IgG treatment, DSG 1 andDSG 3 immunostaining was fragmented at cell borders and partially
relocated to the cytosol. Treatment with inhibitors for PI4K ,PLC , IP3R or CRAC, ameliorated pathogenic effects (Figure
3a/S3a-c).
Retraction of keratin filaments from the cell borders was visible after
24 h of PV-IgG treatment. Treatment with the inhibitors ameliorated the
effect (Figure 3b/S3d). Similarly, cortical F-actin also showed defects
especially close to intercellular gaps after PV-IgG treatment, which was
ameliorated by the respective inhibitors (Figure 3/3S). F-actin staining
was more pronounced following inhibition of PLC compared to
controls (Figure 3/S3) indicating that PLC basal activity might
regulate actin remodelling.