Please use this identifier to cite or link to this item:
|Type:||Artigo de periódico|
|Title:||Staphylococcus Aureus Enterotoxins A And B Inhibit Human And Mice Eosinophil Chemotaxis And Adhesion In Vitro|
De Mello G.C.
|Abstract:||Staphylococcus aureus aggravates the allergic eosinophilic inflammation. We hypothesized that Staphylococcus aureus-derived enterotoxins directly affect eosinophil functions. Therefore, this study investigated the effects of Staphylococcal enterotoxins A and B (SEA and SEB) on human and mice eosinophil chemotaxis and adhesion in vitro, focusing on p38 MAPK phosphorylation and intracellular Ca2+ mobilization. Eosinophil chemotaxis was evaluated using a microchemotaxis chamber, whereas adhesion was performed in VCAM-1 and ICAM-1-coated plates. Measurement of p38 MAPK phosphorylation and intracellular Ca2+ levels were monitored by flow cytometry and fluorogenic calcium-binding dye, respectively. Prior incubation (30 to 240 min) of human blood eosinophils with SEA (0.5 to 3 ng/ml) significantly reduced eotaxin-, PAF- and RANTES-induced chemotaxis (P < 0.05). Likewise, SEB (1 ng/ml, 30 min) significantly reduced eotaxin-induced human eosinophil chemotaxis (P < 0.05). The reduction of eotaxin-induced human eosinophil chemotaxis by SEA and SEB was prevented by anti-MHC monoclonal antibody (1 μg/ml). In addition, SEA and SEB nearly suppressed the eotaxin-induced human eosinophil adhesion in ICAM-1- and VCAM-1-coated plates. SEA and SEB prevented the increases of p38 MAPK phosphorylation and Ca2+ levels in eotaxin-activated human eosinophils. In separate protocols, we evaluated the effects of SEA on chemotaxis and adhesion of eosinophils obtained from mice bone marrow. SEA (10 ng/ml) significantly reduced the eotaxin-induced chemotaxis alongwith cell adhesion to both ICAM-1 and VCAM-1-coated plates (P < 0.05). In conclusion, the inhibition by SEA and SEB of eosinophil functions (chemotaxis and adhesion) are associated with reductions of p38 MAPK phosphorylation and intracellular Ca2+ mobilization.|
|Appears in Collections:||Unicamp - Artigos e Outros Documentos|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.