Pathogenicity of autoantibodies in anti-p200 pemphigoid

PLoS One. 2012;7(7):e41769. doi: 10.1371/journal.pone.0041769. Epub 2012 Jul 24.

Abstract

Recently, the C-terminus of laminin γ1 has been identified as target antigen in anti-p200 pemphigoid and the disease was renamed as anti-laminin γ1 pemphigoid. However, the pathogenic relevance of these autoantibodies has not yet been demonstrated. Therefore, we employed an ex vivo model of autoantibody-mediated leukocyte-dependent neutrophil activation and dermal-epidermal separation (DES) using cryosections of human skin. We showed that anti-p200 pemphigoid sera (n = 7) induced DES in a time-dependent manner, in contrast to sera from healthy controls. Furthermore, laminin γ1-specific IgG and serum depleted from anti-laminin γ1 reactivity were generated using the recombinant C-terminus of laminin γ1 (LAMC1-term; amino acids 1364 to 1609). Interestingly, both fractions labeled the dermal-epidermal-junction (DEJ) by indirect immunofluorescence microscopy on human foreskin and recognized a 200 kDa protein by immunoblotting with dermal extract. Human and rabbit IgG against LAMC1-cterm failed to attract neutrophils at the DEJ and to induce DES. In contrast, patient serum depleted from LAMC1-cterm reactivity led to the same extent of DES as non-depleted IgG. Repeated injection of rabbit anti-murine LAMC1-cterm IgG into both neonatal and adult C57BL/6mice as well as repetitive immunization of various mouse strains with murine LAMC1-cterm failed to induce macro- and microscopic lesions. In all mice, circulating anti-LAMC1-cterm antibodies were present, but only in some mice, IgG deposits were seen at the DEJ. We conclude that autoantibodies in anti-p200 pemphigoid sera are pathogenic while pathogenicity is not mediated by autoantibodies against laminin γ1. Further studies are needed to identify the pathogenically relevant autoantigen in anti-p200 pemphigoid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibody Specificity / immunology
  • Autoantibodies / biosynthesis
  • Autoantibodies / blood
  • Autoantibodies / immunology*
  • Blister / blood
  • Blister / immunology
  • Blister / pathology
  • Cryoultramicrotomy
  • DNA, Complementary / genetics
  • Dermis / immunology
  • Dermis / pathology
  • Epidermis / immunology
  • Epidermis / pathology
  • Epitope Mapping
  • Humans
  • Immune Sera / immunology
  • Immunization
  • Immunization, Passive
  • Immunoglobulin G / immunology
  • Laminin / immunology*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Pemphigoid, Bullous / blood
  • Pemphigoid, Bullous / immunology*
  • Polymerase Chain Reaction
  • Rabbits
  • Recombinant Proteins / immunology

Substances

  • Autoantibodies
  • DNA, Complementary
  • Immune Sera
  • Immunoglobulin G
  • Laminin
  • Recombinant Proteins
  • laminin gamma 1