The flavonoid luteolin inhibits Fcγ-dependent respiratory burst in granulocytes, but not skin blistering in a new model of pemphigoid in adult mice

PLoS One. 2012;7(2):e31066. doi: 10.1371/journal.pone.0031066. Epub 2012 Feb 6.

Abstract

Bullous pemphigoid is an autoimmune blistering skin disease associated with autoantibodies against the dermal-epidermal junction. Passive transfer of antibodies against BP180/collagen (C) XVII, a major hemidesmosomal pemphigoid antigen, into neonatal mice results in dermal-epidermal separation upon applying gentle pressure to their skin, but not in spontaneous skin blistering. In addition, this neonatal mouse model precludes treatment and observation of diseased animals beyond 2-3 days. Therefore, in the present study we have developed a new disease model in mice reproducing the spontaneous blistering and the chronic course characteristic of the human condition. Adult mice were pre-immunized with rabbit IgG followed by injection of BP180/CXVII rabbit IgG. Mice pre-immunized against rabbit IgG and injected 6 times every second day with the BP180/CXVII-specific antibodies (n = 35) developed spontaneous sustained blistering of the skin, while mice pre-immunized and then treated with normal rabbit IgG (n = 5) did not. Blistering was associated with IgG and complement C3 deposits at the epidermal basement membrane and recruitment of inflammatory cells, and was partly dependent on Ly-6G-positive cells. We further used this new experimental model to investigate the therapeutic potential of luteolin, a plant flavonoid with potent anti-inflammatory and anti-oxidative properties and good safety profile, in experimental BP. Luteolin inhibited the Fcγ-dependent respiratory burst in immune complex-stimulated granulocytes and the autoantibody-induced dermal-epidermal separation in skin cryosections, but was not effective in suppressing the skin blistering in vivo. These studies establish a robust animal model that will be a useful tool for dissecting the mechanisms of blister formation and will facilitate the development of more effective therapeutic strategies for managing pemphigoid diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoantigens / immunology
  • Blister / drug therapy*
  • Blister / immunology
  • Chromatography, Affinity
  • Collagen Type XVII
  • Complement C3 / metabolism
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Flow Cytometry
  • Granulocytes / drug effects*
  • Granulocytes / metabolism*
  • Immunoblotting
  • Immunoglobulin G / immunology
  • Immunoglobulin G / pharmacology
  • Luteolin / therapeutic use*
  • Matrix Metalloproteinase 9 / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Neutrophils / metabolism
  • Non-Fibrillar Collagens / immunology
  • Pemphigoid, Bullous / chemically induced*
  • Pemphigoid, Bullous / drug therapy*
  • Pemphigoid, Bullous / immunology
  • Rabbits
  • Reactive Oxygen Species / metabolism
  • Respiratory Burst / drug effects*

Substances

  • Autoantigens
  • Complement C3
  • Immunoglobulin G
  • Non-Fibrillar Collagens
  • Reactive Oxygen Species
  • Matrix Metalloproteinase 9
  • Luteolin