1
|
Wada M, Nishie W, Ujiie H, Izumi K, Iwata H, Natsuga K, Nakamura H, Kitagawa Y, Shimizu H. Epitope-Dependent Pathogenicity of Antibodies Targeting a Major Bullous Pemphigoid Autoantigen Collagen XVII/BP180. J Invest Dermatol 2016; 136:938-946. [PMID: 26827765 DOI: 10.1016/j.jid.2015.11.030] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/07/2015] [Accepted: 11/09/2015] [Indexed: 11/16/2022]
Abstract
In bullous pemphigoid, the common autoimmune blistering disorder, IgG autoantibodies target various epitopes on hemidesmosomal transmembrane collagen XVII (COL17)/BP180. Antibodies (Abs) targeting the extracellular noncollagenous 16th A domain of COL17 may be pathogenic; however, the pathogenic roles of Abs targeting non-noncollagenous 16th A regions are poorly understood. In this study using a pathogenic and a nonpathogenic monoclonal antibody (mAb) targeting the noncollagenous 16th A domain (mAb TS39-3) and the C-terminus domain (mAb C17-C1), respectively, we show that endocytosis of immune complexes after binding of Abs to cell surface COL17 is a key phenomenon that induces skin fragility. Passive transfer of IgG1 mouse mAb TS39-3 but not mAb C17-C1 induces dermal-epidermal separation in neonatal human COL17-expressing transgenic mice. Interestingly, mAb C17-C1 strongly binds with the dermal-epidermal junction of the recipient mice skin, suggesting that binding of Abs with COL17 is insufficient to induce skin fragility. In cultured normal human epidermal keratinocytes treated with these mAbs, mAb TS39-3 but not mAb C17-C1 internalizes immune complexes after binding with cell surface COL17 via macropinocytosis, resulting in reduced COL17 expression. This study shows that pathogenicity of Abs targeting COL17 is epitope dependent, which is associated with macropinocytosis-mediated endocytosis of immune complexes and finally results in the depletion of COL17 expression in basal keratinocytes.
Collapse
Affiliation(s)
- Mayumi Wada
- Department of Dermatology, Hokkaido University, Graduate School of Medicine, Sapporo, Japan; Department of Oral Diagnosis and Medicine, Hokkaido University Graduate School of Dental Medicine, Sapporo, Japan
| | - Wataru Nishie
- Department of Dermatology, Hokkaido University, Graduate School of Medicine, Sapporo, Japan.
| | - Hideyuki Ujiie
- Department of Dermatology, Hokkaido University, Graduate School of Medicine, Sapporo, Japan
| | - Kentaro Izumi
- Department of Dermatology, Hokkaido University, Graduate School of Medicine, Sapporo, Japan
| | - Hiroaki Iwata
- Department of Dermatology, Hokkaido University, Graduate School of Medicine, Sapporo, Japan
| | - Ken Natsuga
- Department of Dermatology, Hokkaido University, Graduate School of Medicine, Sapporo, Japan
| | - Hideki Nakamura
- Department of Dermatology, Hokkaido University, Graduate School of Medicine, Sapporo, Japan
| | - Yoshimasa Kitagawa
- Department of Oral Diagnosis and Medicine, Hokkaido University Graduate School of Dental Medicine, Sapporo, Japan
| | - Hiroshi Shimizu
- Department of Dermatology, Hokkaido University, Graduate School of Medicine, Sapporo, Japan
| |
Collapse
|
2
|
Has C, Nyström A. Epidermal Basement Membrane in Health and Disease. CURRENT TOPICS IN MEMBRANES 2015; 76:117-70. [PMID: 26610913 DOI: 10.1016/bs.ctm.2015.05.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Skin, as the organ protecting the individual from environmental aggressions, constantly meets external insults and is dependent on mechanical toughness for its preserved function. Accordingly, the epidermal basement membrane (BM) zone has adapted to enforce tissue integrity. It harbors anchoring structures created through unique organization of common BM components and expression of proteins exclusive to the epidermal BM zone. Evidence for the importance of its correct assembly and the nonredundancy of its components for skin integrity is apparent from the multiple skin blistering disorders caused by mutations in genes coding for proteins associated with the epidermal BM and from autoimmune disorders in which autoantibodies target these molecules. However, it has become clear that these proteins not only provide mechanical support but are also critically involved in tissue homeostasis, repair, and regeneration. In this chapter, we provide an overview of the unique organization and components of the epidermal BM. A special focus will be given to its function during regeneration, and in inherited and acquired diseases.
Collapse
Affiliation(s)
- Cristina Has
- Department of Dermatology, University Medical Center Freiburg, Freiburg, Germany
| | - Alexander Nyström
- Department of Dermatology, University Medical Center Freiburg, Freiburg, Germany
| |
Collapse
|