F165(1) fimbriae of the P fimbrial family inhibit the oxidative response of porcine neutrophils.
The F165(1) fimbrial system has been associated with the resistance of Escherichia coli O115:K"V165" to phagocytic killing by porcine polymorphonuclear leukocytes (PMNLs). One mechanism of this resistance seemed to be inhibition of the oxidative response as observed following induction of PMNLs by phorbol myristate acetate (PMA) and treatment with bacteria possessing the F165(1) fimbriae. In order to confirm whether or not the F165(1) fimbriae are involved in this inhibition, we evaluated the effect of F165(1)-positive strains (a pathogenic wild-type strain 5131, and a recombinant strain HB101(pCJ7)) or an F165(1)-negative strain HB101 (used as negative control) on the oxidative response of porcine neutrophils (pNs) stimulated with PMA. Incubation of pNs with pathogenic E. coli strain 5131 resulted in significant inhibition of the oxidative response as compared to that observed for pNs incubated without bacteria, as assessed by hydrogen peroxide (H2O2) and superoxide anion (O2-) release from the phagocytes, and by the chemiluminescence assay. Similarly, incubation of pNs with the F165(1)-producing cloned strain HB101(pCJ7) resulted in significant inhibition of the pN oxidative response as compared to that observed for pNs incubated without bacteria or with strain HB101. In contrast, addition of purified F165(1) fimbriae to the pNs had no effect on the oxidative response.
Ngeleka
M
M
School of Veterinary Medicine, Faculty of Medical Sciences, The University of the West Indies, St-Augustine, Trinidad and Tobago.
Fairbrother
J M
JM
D000818:Animals; D000942:Antigens, Bacterial; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology*; D004927:Escherichia coli Infections / Q000662:veterinary; D029968:Escherichia coli Proteins; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial / Q000276:immunology*; D006861:Hydrogen Peroxide / Q000032:analysis; D009504:Neutrophils / Q000276:immunology*; D010587:Phagocytosis; D016897:Respiratory Burst; D013481:Superoxides / Q000032:analysis; D013552:Swine; D013553:Swine Diseases / Q000276:immunology
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C088773:F165 protein, E coli; D013481:Superoxides; D036781:Fimbriae Proteins; D006861:Hydrogen Peroxide