Étude des interactions entre Haemophilus parasuis et des cellules endothéliales et épithéliales porcines: implications d’une composante bactérienne, le lipooligosaccharide (LOS)
Haemophilus parasuis is a swine pathogen that causes Glässer’s disease characterized by fibrinous polyserositis, polyarthritis, meningitis and septicemia. The pathogenesis of the infection and virulence factors are not well known. Whether the upper respiratory tract is the site of colonization of H. parasuis is still a controversial issue. H. parasuis must invade the mucosa to gain access to the bloodstream. H. parasuis is able to adhere to newborn pig trachea cells (NPTr). H. parasuis must then cross the blood-brain barrier to gain access to the central nervous system in cases of meningitis. H. parasuis is able to adhere to and invade porcine brain microvascular endothelial cells (PBMEC). The aim of this work was to study the interactions between H. parasuis, its lipooligosccharide (LOS), and porcine endothelial and epithelial cells. Results showed that adhesion of H. parasuis Nagasaki to NPTr and PBMEC was partially mediated by its LOS. H. parasuis induced NPTr and PBMEC apoptosis, although purified LOS does not seem to be involved. H. parasuis, and to a lesser extent its LOS, stimulated the release of interleukin- (IL) 6 and IL-8. Field strains of H. parasuis serotypes 4 and 5 (the most prevalent serotypes in North America) also induced the production of IL-6 and IL-8. Results suggest that H. parasuis LOS plays a role in the pathogenesis of the infection, but other bacterial components are also involved.
Haemophilus parasuis Haemophilus parasuis Lipooligosaccharide Lipooligosaccharide Adhesion Apoptosis Induction of cytokines Endothelial cells Epithelial cells