Fig. 1.

A mixture of pathogenic and non-pathogenic IgG monoclonal antibodies (mAbs) induced clustering of desmoglein 1 (Dsg1) in the organ-cultured human skin. Each individual mAb and a mixture of anti-Dsg1 IgG mAbs were injected into human skin specimens that were then cultured for 22–24 h. The skins were harvested for histology after mechanical shear stress by slight friction of epidermis. Histology and direct immunofluorescence of IgG deposits and staining of Dsg1 were captured by confocal microscopy. PF1-8-15 IgG (50 μg) caused superficial epidermal acantholysis (A), but PF1-2-6 IgG (50 μg) did not (E). Note that an individual injection of PF1-8-15 IgG or PF1-2-6 IgG showed of IgG and Dsg1 linear distribution cell surface of keratinocytes on F–H), while the mixture injection of PF1-8-15 IgG (50 μg) the and PF1-2-6 IgG (50 μg) (B–D, (PF1-8-15 IgG + PF1-2-6 IgG) showed aberrant granular IgG and Dsg1 distribution in the lower epidermis (J–L), in addition to superficial acantholytic blister (I). In PBS, epidermal morphology and Dsg1 distribution were normal (M, O) with no detectable IgG deposition in the epidermis (N). Bar = 20 μm.