Feldrihan Vasile, Licarete Emilia, Florea Florina, Cristea Victor, Popescu Octavian, Sitaru Cassian, Chiriac Mircea Teodor
Faculty of Medicine, Iuliu-Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania; Department of Dermatology, University of Freiburg, Freiburg, Germany.
Department of Dermatology, University of Freiburg, Freiburg, Germany; Department of Biology, Babes-Bolyai University, Cluj-Napoca, Romania.
Hum Immunol. 2014 Apr;75(4):354-63. doi: 10.1016/j.humimm.2014.01.005. Epub 2014 Jan 24.
Bullous pemphigoid, the most common autoimmune blistering disease in Western Europe and the USA is characterized by the presence of circulating and tissue-bound autoantibodies against the hemidesmosomal proteins BP230 and BP180/collagen XVII. After binding to their target antigens at the basement membrane of the dermal-epidermal junction these autoantibodies are thought to trigger an inflammatory cascade comprising complement- and granulocyte-dependent reactions that result in tissue damage. Whereas the role of anti-BP180 antibodies has been extensively characterized, few and conflicting data is available on the contribution of anti-BP230 antibodies to bullous pemphigoid pathogenesis. Therefore, we addressed in the present study the role of autoantibodies to BP230 in experimental bullous pemphigoid. Rabbit polyclonal antibodies generated against epitopes of the C-terminal fragment of murine BP230 bound to the basement membrane and activated the complement system ex vivo. Affinity-purified antibodies were subsequently subcutaneously transferred into neonatal and adult BALB/c mice. In vivo, we observed a dose-dependent binding of transferred antibodies in the murine skin; however, there was no complement activation and these mice showed no clinical or histological signs of inflammatory disease, in contrast to mice receiving anti-BP180 antibodies. We further conducted ex vivo experiments and demonstrated that rabbit IgG anti-BP230-specific antibodies, in contrast to antibodies from bullous pemphigoid patients or rabbit IgG anti-BP180 antibodies used as positive controls, did not activate human granulocytes to induce dermal-epidermal separation in skin cryosections. Our present findings demonstrate that antibodies against BP230 are non-pathogenic in experimental models of bullous pemphigoid and suggest that proper activation of the complement and granulocytes represent prerequisites for conferring bullous pemphigoid autoantibodies their tissue destructive potential.
大疱性类天疱疮是西欧和美国最常见的自身免疫性水疱病，其特征是存在针对半桥粒蛋白BP230和BP180/ XVII型胶原蛋白的循环自身抗体和组织结合自身抗体。这些自身抗体在真皮-表皮交界处的基底膜与靶抗原结合后，被认为会引发包括补体和粒细胞依赖性反应在内的炎症级联反应，从而导致组织损伤。尽管抗BP180抗体的作用已得到广泛研究，但关于抗BP230抗体在大疱性类天疱疮发病机制中的作用，现有数据较少且相互矛盾。因此，在本研究中，我们探讨了抗BP230自身抗体在实验性大疱性类天疱疮中的作用。针对小鼠BP230 C末端片段表位产生的兔多克隆抗体与基底膜结合，并在体外激活补体系统。随后将亲和纯化的抗体皮下注射到新生和成年BALB/c小鼠体内。在体内，我们观察到所注射的抗体在小鼠皮肤中呈剂量依赖性结合；然而，与接受抗BP180抗体的小鼠不同，这些小鼠没有补体激活，也没有出现炎症性疾病的临床或组织学迹象。我们进一步进行了体外实验，结果表明，与大疱性类天疱疮患者的抗体或用作阳性对照的兔抗BP180抗体不同，兔抗BP230特异性IgG抗体不能激活人粒细胞，从而在皮肤冰冻切片中诱导真皮-表皮分离。我们目前的研究结果表明，在大疱性类天疱疮的实验模型中，抗BP230抗体无致病性，并提示补体和粒细胞的适当激活是赋予大疱性类天疱疮自身抗体组织破坏潜能的先决条件。
