Phylogenetic Studies of the Bullous Pemphigoid Antigen-1 Using Human Monoclonal-antibodies

Abstract

Bullous pemphigoid is an autoimmune skin disorder with production of autoantibodies against bullous pemphigoid antigen 1 (BPAg1) and bullous pemphigoid antigen 2 (BPAg2) which are constitutively expressed in hemdesmosomes. Phylogenetic study of the reactivity of 3 human monoclonal antibodies (HuMabs) specific for BPAg1 was performed using immunohistochemical analysis of skin sections. The serum of the 2 BP patients from which the 3 HuMabs were derived stained the basement membrane zone on skin cryostat section of all species tested including fishes, amphibians, reptiles, birds and mammals. However, of the 3 HuMabs BP1, BP2 and BP3, only BP3 reacted with the skin of reptiles, birds and mammals while Bp1 and Bp2 exclusively bound to mammalian skin. These data provide evidence for the existence of multiple epitopes on BPAg1 able to bind autoantibodies