Some Biochemical Properties of Pemphigoid Antigen Bound to the Surface of Dissociated Epidermal Basal Cells

Abstract

Bullous pemphigoid antigen (BP Ag) is a cell surface marker of epidermal basal cells. The functional role of this molecule is unknown. Epidermal cell suspensions obtained by trypsinization of skin show a population of epidermal basal cells with a polar rim of antigen as demonstrated by indirect immunofluorescence technique. This study shows that treatment of these cells suspensions with a variety of proteolytic and glycosidic enzymes failed to remove the antigen from these basal cells. BP Ag was also stable upon incubation with distilled water, Triton X-100, PBS, and 1 M NaCl. Treatment of epidermal basal cells with 2 N NaSCN, 1% periodic acid, and 4 M urea, as well as acidic pH or 56 degrees C temperature, abolished the reactivity of these cells with BP antibodies.

Human autoantibodies against the 230-kD bullous pemphigoid antigen (BPAG1) bind only to the intracellular domain of the hemidesmosome, whereas those against the 180-kD bullous pemphigoid antigen (BPAG2) bind along the plasma membrane of the hemidesmosome in normal human and swine skin.

“…BP antigens are normal components of the hemidesmosome complex of the BMZ, which are thought to be important not only in the pathogenesis of BP but also in dermoepidermal adhesion. Since Diaz and his coworkers initially reported small molecular weight antigenic proteins recognized by BP sera (5,6), considerable efforts have been spent in characterizing the BP antigen (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). Recently, a 220-240-kD protein (230-kD BP antigen, BPAG1) and a 180-160-kD protein ( 1 80-kD BP antigen, BPAG2) have been identified as two major BP antigens by immunoprecipitation (7) and Western immunoblotting (10,12,13,14).…”

Use of intravenous immunoglobulin therapy in autoimmune blistering diseases

“…In patients with a negative IIF, the diagnosis can be confirmed by using salt split skin (SSS) assay or by immunoblot and more recently by ELISA [82][83][84][85][86][87]. The autoantibodies in BP recognize 2 very distinct auto-antigens present in the hemidesmosome within the basal keratinocytes.…”

“…The autoantibodies in BP recognize 2 very distinct auto-antigens present in the hemidesmosome within the basal keratinocytes. The BP antigen 1(BP230) is a 230 kDa in protein and is con- sidered to be a desmoplakin protein [84,85]. BP antigen (BP180) is a hemidesmosomal 2 180 kDa protein, that has a cytoplasmic and intracellular component [84,85].…”

“…The BP antigen 1(BP230) is a 230 kDa in protein and is con- sidered to be a desmoplakin protein [84,85]. BP antigen (BP180) is a hemidesmosomal 2 180 kDa protein, that has a cytoplasmic and intracellular component [84,85]. In 2 recent studies an ELISA for BP180 was described and is considered to be more sensitive than IIF in detecting BP autoantibodies [86,87].…”

Sorting of basal cells with FACS IV (fluorescence activated cell sorter)

“…The third takes advantage of the preferential adherence of basal cells to collagen (Skerrow & Skerrow, 1983). Here, we used another method based on the fact that after dissociation with trypsin-EDTA, basal cells retain at their surface the bullous pemphigoid antigen (BPA) (Grekin et al, 1981), a specific constituent of the basement membrane zone. Since this antigen can be revealed by specific antibodies and indirect immunofiuorescence (Beutner, Jordon & Chorzelski, 1968), a fluorescence-activated cell sorter was used to select out basal cells after reacting them with BP antisera (dilution i: 100) in fresh unfixed suspensions.…”