ST18 Enhances PV-IgG-Induced Loss of Keratinocyte Cohesion in Parallel to Increased ERK Activation

Frontiers in Immunology

Elias Walter¹  Mariya Y. Radeva¹  Jens Waschke¹  Amir S. Yazdi²  Ofer Sarig³  Ramona Alexandra Stach⁴  Nicolas Schlegel⁵  Eli Sprecher⁶ 

[1] Department I, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany;Department of Dermatology, RWTH Aachen, Aachen, Germany;Department of Dermatology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel;Department of Dermatology, University Medical Center Tübingen, Eberhard Karls University, Tübingen, Germany;Department of General, Visceral, Vascular and Paediatric Surgery, Julius-Maximilians-Universität, Würzburg, Germany;Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel;

关键词: pemphigus;    desmosome;    desmoglein;    ST18;    ERK;    cytokines;   

DOI  :  10.3389/fimmu.2019.00770

来源: DOAJ

【 摘 要 】

Pemphigus is an autoimmune blistering disease targeting the desmosomal proteins desmoglein (Dsg) 1 and Dsg3. Recently, a genetic variant of the Suppression of tumorigenicity 18 (ST18) promoter was reported to cause ST18 up-regulation, associated with pemphigus vulgaris (PV)-IgG-mediated increase in cytokine secretion and more prominent loss of keratinocyte cohesion. Here we tested the effects of PV-IgG and the pathogenic pemphigus mouse anti-Dsg3 antibody AK23 on cytokine secretion and ERK activity in human keratinocytes dependent on ST18 expression. Without ST18 overexpression, both PV-IgG and AK23 induced loss of keratinocyte cohesion which was accompanied by prominent fragmentation of Dsg3 immunostaining along cell borders. In contrast, release of pro-inflammatory cytokines such as IL-1α, IL-6, TNFα, and IFN-γ was not altered significantly in both HaCaT and primary NHEK cells. These experiments indicate that cytokine expression is not strictly required for loss of keratinocyte cohesion. Upon ST18 overexpression, fragmentation of cell monolayers increased significantly in response to autoantibody incubation. Furthermore, production of IL-1α and IL-6 was enhanced in some experiments but not in others whereas release of TNF-α dropped significantly upon PV-IgG application in both EV- and ST18-transfected HaCaT cells. Additionally, in NHEK, application of PV-IgG but not of AK23 significantly increased ERK activity. In contrast, ST18 overexpression in HaCaT cells augmented ERK activation in response to both c-IgG and AK23 but not PV-IgG. Because inhibition of ERK by U0126 abolished PV-IgG- and AK23-induced loss of cell cohesion in ST18-expressing cells, we conclude that autoantibody-induced ERK activation was relevant in this scenario. In summary, similar to the situation in PV patients carrying ST18 polymorphism, overexpression of ST18 enhanced keratinocyte susceptibility to autoantibody-induced loss of cell adhesion, which may be caused in part by enhanced ERK signaling.

【 授权许可】

Unknown