Bovine macrophages sense Escherichia coli Shiga toxin 1

摘要: Shiga toxin (Stx)-producing Escherichia coli (STEC) infections in cattle are asymptomatic; however, Stx impairs the initiation of an adaptive immune response by targeting bovine peripheral and intraepithelial lymphocytes. As presumptive mucosal macrophages (Mo) also sensitive to Stx, STEC may even exert modulatory effects acting on steps preceding lymphocyte activation at Mo level. We therefore studied expression receptor (CD77), cellular phenotype functions after incubation primary monocyte-derived with purified Stx1. A significant portion expressed CD77 their surface, recombinant B-subunit Stx1 binding >50% cells. down-regulated significantly surface CD14, CD172a co-stimulatory molecules CD80 CD86 within 4 h incubation, while MHC-II remained unaffected. Furthermore, increased numbers transcripts for IL-4, IL-6, IL-10, IFN-γ, TNF-α, IL-8 GRO-α but not IL-12, TGF-β, MCP-1 RANTES. In course infections, appears induce a mixed pattern reminiscent regulatory Mo, which amplify direct suppressive effect