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Saliva induces expression of antimicrobial peptides and promotes intracellular killing of bacteria in keratinocytes by epidermal growth factor receptor transactivation
Author(s) -
Mohanty T.,
Alberius P.,
Schmidtchen A.,
Reiss K.,
Schröder J.M.,
Sørensen O.E.
Publication year - 2017
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1111/bjd.14883
Subject(s) - saliva , antimicrobial peptides , transactivation , biology , keratinocyte , epidermal growth factor receptor , innate immune system , immunology , microbiology and biotechnology , immune system , gene expression , receptor , in vitro , antimicrobial , biochemistry , gene
Summary Background Wounds in the oral cavity, constantly exposed to both saliva and bacteria, heal quickly without infection. Furthermore, during licking of skin wounds, saliva promotes wound healing and plays a role in keeping the wound free of infection. Objectives To investigate whether saliva induces expression of antimicrobial peptides ( AMP s) in human epidermal keratinocytes and whether saliva promotes clearance of intracellular bacteria in these cells. Methods Expression of AMP s was investigated in the oral mucosa and ex vivo injured skin by immunohistochemistry. Human beta‐defensin‐3 expression was investigated in epidermal keratinocytes after saliva stimulation, using real‐time polymerase chain reaction and immunofluorescence. Results We found higher expression of AMP s in the oral mucosa than in the epidermis. Saliva accelerated the injury‐induced expression of AMP s in human skin ex vivo and was a potent inducer of the expression of AMP s in epidermal keratinocytes. The expression of AMP s was induced by metalloproteinase‐dependent epidermal growth factor receptor ( EGFR ) transactivation mediated by a salivary lipid. Saliva increased the intracellular clearance of Staphylococcus aureus in keratinocytes through EGFR activation. Conclusions These findings suggest a previously unreported role of saliva in innate immunity and demonstrate for the first time that saliva induces gene expression in epidermal keratinocytes.