Premium
sCD 48 is anti‐inflammatory in Staphylococcus aureus Enterotoxin B‐induced eosinophilic inflammation
Author(s) -
Gangwar R. S.,
LeviSchaffer F.
Publication year - 2016
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1111/all.12851
Subject(s) - staphylococcus aureus , enterotoxin , inflammation , medicine , eosinophilic , microbiology and biotechnology , immunology , biology , bacteria , pathology , escherichia coli , genetics , biochemistry , gene
Background Staphylococcus aureus , one of the most important pathogens, is heavily associated with allergy. S. aureus and its toxins interact with eosinophils through CD 48, a GPI ‐anchored receptor important in allergy mainly as expressed by the eosinophils ( mCD 48). CD 48 can exist in a soluble form ( sCD 48). Our aim was to investigate SEB ‐induced regulation of eosinophil CD 48 and the possible formation and role of sCD 48 in SEB ‐mediated eosinophil activation in vitro and in vivo . Methods Human peripheral blood eosinophils were activated by SEB with or without inhibitors for phospholipases ( PL ) (‐C or ‐D), or cycloheximide, or brefeldin A. We evaluated eosinophil activation ( CD 11b expression or EPO / IL ‐8 release), mCD 48 (flow cytometry), sCD 48 ( ELISA ), SEB binding to sCD 48 ( ELISA ), and chemotaxis toward SEB . C57 BL /6 mice were pre‐injected (ip.) with sCD 48, and then, peritonitis was induced by SEB injection; peritoneal lavages were collected after 48 h and analyzed by flow cytometry and ELISA. Results SEB ‐activated human eosinophils formed sCD 48, directly correlating with CD 11b expression, through cell‐associated PL ‐C and ‐D. mCD 48 remained stable due to up‐regulation in CD 48 transcription and cellular trafficking. sCD 48 bound to SEB and down‐regulated SEB stimulatory effects on eosinophils as assessed by EPO and IL ‐8 release and eosinophil chemotaxis toward SEB . sCD 48 showed anti‐inflammatory activity in a SEB ‐induced mouse peritonitis model. Conclusions SEB regulates CD 48 dynamics on eosinophils. Our data indicate sCD 48 as a SEB ‐induced ‘decoy’ receptor derived from eosinophil and therefore as a potential anti‐inflammatory tool in S. aureus ‐induced eosinophil inflammation often associated with allergy.