Early cytokine response of gnotobiotic piglets to Salmonella enterica serotype Typhimurium

Abstract

Cytokine response against Salmonella Typhimurium is traditionally studied in conventional animals. Germ-free animals, however, enable to study response against infection without background effect of other microorganisms. Plasma and ileal inflammatory cytokines in germ-free piglets orally infected with virulent LT2 strain or, with a non-virulent SF1591 rough mutant were quantified by ELISA. In plasma and ileal washes, IFN-γ levels significantly increased in both infected groups. TNF-α and IL-18 were mostly missing in plasma 24 h after infection. In the ileum, IFN-γ, TNF-α, and IL-1β were induced mainly by the virulent strain, whereas IL-18 was induced in highest quantity by non-virulent Salmonella. These data confirmed an important role of IFN-γ, as well as other inflammatory cytokines in early stage of salmonellosis.