Recent progress in studies on autoantigens for various autoimmune blistering skin diseases

Autoimmune blistering skin diseases develop separation either between epidermal keratinocytes or dermo-epidermal junction. Recent studies have revealed that the autoantigens for these diseases are components of either the desmosome, the cell adhesion junction between keratinocytes, or the hemidesmosome complex, cell adhesion machinery at the dermo-epidermal junction. Thus, the major pemphigus antigens are desmogleins, one of desmosomal cadherins. Both the 230 kD and 180 kD bullous pemphigoid antigens are present in the hemidesmosome, and epidermal basement membrane zone-specific extracellular matrices, epiligrin and type VII collagen, are detected by sera of cicatricial pemphigoid and epidermolysis bullosa acquisita, respectively. Furthermore, animal model studies using newborn mice have revealed that these autoantibodies are really pathogenic and can induce blister formation by passive transfer into mice. Therefore, these skin diseases seem to be a typical model for various autoimmune diseases, for most of which the role of autoantibodies has not yet been revealed.