Pathogenic Activation and Therapeutic Blockage of FcozR-Expressing Polymorphonuclear Leukocytes in IgA Pemphigus

[摘要] Pathomechanisms in IgA pemphigus are assumed to rely on Fc-dependent cellular activation by antigenspecific IgA autoantibodies; however, models for the disease and more detailed pathophysiologic data are lacking. In this study, we aimed to establish in vitro models of disease for IgA pemphigus, allowing us to study the effects of the interaction of anti-keratinocyte IgA with cell surface FcaRs. Employing multiple in vitro assays, such as a skin cryosection assay and a human skin organ culture model, in this study, we present mechanistic data for the pathogenesis of IgA pemphigus, mediated by anti-desmoglein 3 IgA autoantibodies. Our results reveal that this disease is dependent on FcaR-mediated activation of leukocytes in the epidermis. Importantly, this cell-dependent pathology can be dose-dependently abrogated by peptide-mediated inhibition of FcaR:IgAFc interaction, as confirmed in an additional model for IgA-dependent disease, that is, IgA vasculitis. These data suggest that IgA pemphigus can be modeled in vitro and that IgA pemphigus and IgA vasculitis are FcaRdependent disease entities that can be specifically targeted in these experimental systems.

[发布日期] 2021-12-01