E de Graauw1, C Sitaru2,3, M P Horn4, L Borradori5, S Yousefi1, D Simon5, H-U Simon1. 1. Institute of Pharmacology, University of Bern, Bern, Switzerland. 2. Department of Dermatology, University Medical Center Freiburg, Freiburg, Germany. 3. BIOSS Centre for Biological Signalling Studies, Albert Ludwig University of Freiburg, Freiburg, Germany. 4. University Institute of Clinical Chemistry and Centre of Laboratory Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland. 5. Department of Dermatology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Abstract
BACKGROUND: Lesions of bullous pemphigoid (BP), an autoimmune subepidermal blistering disease characterized by the presence of tissue-bound and circulating autoantibodies to hemidesmosomal antigens, harbor a mixed inflammatory cellular infiltrate. In various models, neutrophils, eosinophils, mast cells, monocytes as well as B and T cells have been shown to be involved in the pathogenesis of BP. However, their interactions with and effective role in blister formation remain uncertain. This study was aimed at investigating the effect of monocyte/neutrophil interaction on blister formation in an ex vivo BP model. METHODS: Skin cryosections were incubated with purified human neutrophils and monocytes, in the presence or absence of BP autoantibodies. Production of reactive oxygen species (ROS), degranulation, mediator release (neutrophil elastase [NE], myeloperoxidase [MPO], matrix metalloproteinase-9 [MMP-9]), binding of Fcγ receptor (CD16, CD32, CD64), and cell adhesion (CD18, ICAM-1) was investigated using appropriate inhibitors. Dermal-epidermal separation (DES) was assessed by light microscopy and quantified by Fiji software. RESULTS: Monocytes and neutrophils synergistically interact resulting in a significantly higher DES compared to either monocytes or neutrophils separately (P < .0001). Monocyte/neutrophil-induced DES was associated with increased ROS production and was dependent on adhesion and FcγRIII binding. Upon stimulation by the granule-poor fraction of monocyte supernatants, neutrophils increased their release of MMP-9, thereby also DES at the dermal-epidermal junction of skin cryosections. CONCLUSION: Our observations suggest that the interaction of cells, as shown here for monocytes and neutrophils, enhances mediator release resulting in an increased subepidermal blister formation. Thus, blocking intercellular cross talk promises a new therapeutic approach for blocking tissue damage in BP.
BACKGROUND: Lesions of bullous pemphigoid (BP), an autoimmune subepidermal blistering disease characterized by the presence of tissue-bound and circulating autoantibodies to hemidesmosomal antigens, harbor a mixed inflammatory cellular infiltrate. In various models, neutrophils, eosinophils, mast cells, monocytes as well as B and T cells have been shown to be involved in the pathogenesis of BP. However, their interactions with and effective role in blister formation remain uncertain. This study was aimed at investigating the effect of monocyte/neutrophil interaction on blister formation in an ex vivo BP model. METHODS: Skin cryosections were incubated with purified human neutrophils and monocytes, in the presence or absence of BP autoantibodies. Production of reactive oxygen species (ROS), degranulation, mediator release (neutrophil elastase [NE], myeloperoxidase [MPO], matrix metalloproteinase-9 [MMP-9]), binding of Fcγ receptor (CD16, CD32, CD64), and cell adhesion (CD18, ICAM-1) was investigated using appropriate inhibitors. Dermal-epidermal separation (DES) was assessed by light microscopy and quantified by Fiji software. RESULTS: Monocytes and neutrophils synergistically interact resulting in a significantly higher DES compared to either monocytes or neutrophils separately (P < .0001). Monocyte/neutrophil-induced DES was associated with increased ROS production and was dependent on adhesion and FcγRIII binding. Upon stimulation by the granule-poor fraction of monocyte supernatants, neutrophils increased their release of MMP-9, thereby also DES at the dermal-epidermal junction of skin cryosections. CONCLUSION: Our observations suggest that the interaction of cells, as shown here for monocytes and neutrophils, enhances mediator release resulting in an increased subepidermal blister formation. Thus, blocking intercellular cross talk promises a new therapeutic approach for blocking tissue damage in BP.
Authors: Melanie Wannick; Julian C Assmann; Jakob F Vielhauer; Stefan Offermanns; Detlef Zillikens; Christian D Sadik; Markus Schwaninger Journal: Front Immunol Date: 2018-08-14 Impact factor: 7.561
Authors: Delphine Giusti; Estela Bini; Christine Terryn; Kevin Didier; Sébastien Le Jan; Grégory Gatouillat; Anne Durlach; Stéphane Nesmond; Celine Muller; Philippe Bernard; Frank Antonicelli; Bach Nga Pham Journal: Front Immunol Date: 2019-04-04 Impact factor: 7.561