Exopolysaccharides from Cyanobacterium aponinum induce a regulatory dendritic cell phenotype and inhibit SYK and CLEC7A expression in dendritic cells, T cells and keratinocytes.

• Published in: International Immunopharmacology
• Main Authors: Gudmundsdottir, Asa B, Brynjolfsdottir, Asa, Olafsdottir, Elin Soffia, Hardardottir, Ingibjorg, Freysdottir, Jona
• Other Authors: 1 Faculty of Medicine, University of Iceland, Biomedical Center, Vatnsmyrarvegur 16, IS-101 Reykjavik, Iceland; Department of Immunology, Landspitali-The National University Hospital of Iceland, Bld 14 at Eiriksgata, IS-101 Reykjavik, Iceland; Center for Rheumatology Research, Landspitali-The National University Hospital of Iceland, Bld 14 at Eiriksgata, IS-101 Reykjavik, Iceland. 2 Blue Lagoon, Nordurljosavegur 9, IS-240 Grindavik, Iceland. 3 Faculty of Pharmaceutical Sciences, University of Iceland, Hofsvallagata 53, IS-107 Reykjavik, Iceland. 4 Faculty of Medicine, University of Iceland, Biomedical Center, Vatnsmyrarvegur 16, IS-101 Reykjavik, Iceland; Department of Immunology, Landspitali-The National University Hospital of Iceland, Bld 14 at Eiriksgata, IS-101 Reykjavik, Iceland. 5 Faculty of Medicine, University of Iceland, Biomedical Center, Vatnsmyrarvegur 16, IS-101 Reykjavik, Iceland; Department of Immunology, Landspitali-The National University Hospital of Iceland, Bld 14 at Eiriksgata, IS-101 Reykjavik, Iceland; Center for Rheumatology Research, Landspitali-The National University Hospital of Iceland, Bld 14 at Eiriksgata, IS-101 Reykjavik, Iceland. Electronic address: [e-mail].
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier Science 2019
• Subjects: CAMP; CLEC7A; Dendritic cells; Keratinocytes; Syk signaling pathway; T cells; Sóríasis; Psoriasis; Blue Lagoon; Iceland
• Online Access: http://hdl.handle.net/2336/620926; https://doi.org/10.1016/j.intimp.2019.01.044

To access publisher's full text version of this article click on the hyperlink below Regular bathing in the Blue Lagoon has beneficial effects on psoriasis. Previously, we showed that exopolysaccharides (EPS-Ca) secreted by Cyanobacterium aponinum, a dominating organism in the Blue Lagoon, increased IL-10 secretion by human dendritic cells (DCs). In addition, co-culturing allogeneic CD4+ T cells with DCs matured in the presence of EPS-Ca increased differentiation of T cells into T regulatory cells at the cost of the disease inducing Th17 cells. In the present study, EPS-Ca increased the proportion of DCs expressing CD141, a surface molecule linked to regulatory DCs, and the CD141+ cells secreted more IL-10 than the CD141- cells. EPS-Ca decreased T cell secretion of IL-17, IL-13 and IL-10 and the proportion of T cells expressing the activation marker CD69 that has also been linked to lymphocyte retention. In addition, EPS-Ca reduced keratinocyte secretion of CCL20 and CXCL10, chemokines implicated in recruitment of inflammatory cells. EPS-Ca decreased DC expression of Dectin-1/CLEC7A and SYK, keratinocyte expression of CLEC7A, SYK and CAMP (the gene for LL37), and T cell expression of phosphorylated Zap70. These results indicate that EPS-Ca may induce a regulatory phenotype of DCs, T cells that are less active/inflammatory and less prone to being retained in the skin, and keratinocytes that induce less recruitment of inflammatory cells to the skin and that these effects may be mediated by the effects of EPS-Ca on CLEC7A and SYK. Overall the results indicate that EPS-Ca may be involved in the beneficial effects psoriasis patients experience when bathing in the Blue Lagoon. Icelandic Centre for Research Technology Development Fund Landspitali University Hospital Research Fund University of Iceland Research Fund