A passive transfer model of the organ-specific autoimmune disease, bullous pemphigoid, using antibodies generated against the hemidesmosomal antigen, BP180.

Abstract

Subepidermal blistering associated with the human skin diseases bullous pemphigoid and herpes gestationis has been thought to be an IgG autoantibody-mediated process; however, previous attempts to demonstrate the pathogenicity of patient autoantibodies have been unsuccessful. An immunodominant and potentially pathogenic epitope associated with these blistering diseases has recently been mapped to the extracellular domain ofa human epidermal antigen, BP180. Patient autoantibodies that react with this well-defined antigenic site failed to crossreact with the murine form of this autoantigen and thus could not be assayed for pathogenicity in a conventional passive transfer mouse model. As an alternative, rabbit polyclonal antibodies were generated against a segment of the murine BP180 protein homologous with the human BP180 autoantibodyreactive site and were passively transferred into neonatal BALB/c mice. The injected animals developed a subepidermal blistering disease that closely mimicked bullous pemphigoid and herpes gestationis at the clinical, histological, and immunological levels. Autoantibodies that recognize the human BP180 ectodomain are therefore likely to play an initiatory role in the pathogenesis of bullous pemphigoid and herpes gestationis. (J.

A major role for neutrophils in experimental bullous pemphigoid.

“…The preparation of recombinant mBP180 and the immunization of rabbits were performed as previously described (12). Briefly, a segment of the mBP180 antigen encompassing amino acids 495-643 of the ectodomain of this protein (using the numbering system of Li et al [16]) was expressed as a glutathione S -transferase (GST) fusion protein using the pGEX prokaryotic expression system (Pharmacia LKB Biotechnology, Piscataway, NJ).…”

“…This fusion protein, designated GST-mBP180ABC, was purified to homogeneity by affinity chromatography (17). New Zealand White rabbits were immunized with the purified mBP180 fusion protein, and the IgG fraction from the sera (referred to as R50, R621, and R622) was purified as previously described (12,18). The IgG fractions were concentrated, sterilized by ultrafiltration, and the protein concentrations were determined by OD 280 [E (1%, 1 cm) ϭ 13.6].…”

“…Recently, our laboratory has developed an experimental model of BP which involves the passive transfer of antimBP180 antibodies into neonatal BALB/c mice (12). The BP mouse model reproduces the key immunopathological features of this human autoimmune disease, i.e., IgG and complement deposition at the DEJ, inflammatory infiltration of the upper dermis, and subepidermal blistering.…”

Evaluation of Recombinant Antigen-Based Assays for Diagnosis of Bullous Autoimmune Diseases

“…In BP, autoantibodies are directed against the normal components of hemidesmosomes, BP180 and BP230. The pathogenetic role of BP180 has been demonstrated to be localized on the noncollagenous portion (NC16A) of its extracellular domain (12,19), so the NC16A between BP180 and the recombinant peptide has been used to develop the EIA that was used in this study.…”

“…The detection of circulating or tissue-bound autoantibodies by immunofluorescence assay (IFA) is an important criterion for diagnosis in both clinical conditions (14). Recently, enzyme immunoassays (EIAs) based on recombinant desmoglein-1 (Dsg1) or Dsg3, the main autoantigens in pemphigus (1), and on recombinant BP180, the hemidesmosomal autoantigen involved in the pathogenesis of bullous pemphigoid (BP) (12,19), have been commercialized. In the present study we have analyzed retrospectively the levels of anti-Dsg1 and anti-Dsg3 in the sera of patients with diagnoses of pemphigus and the levels of anti-BP180 in the sera of patients with pemphigoid in order to establish the correlation between the serum reactivity and clinical features of the patients.…”