Cytokine gene expression profiles in chicken spleen and intestinal tissues during Ascaridia galli infection

a b s t r a c t In the poultry production industry, chickens with access to outdoor areas are exposed to a wide range of parasites e.g. the helminth Ascaridia galli. By real-time quantitative RT- PCR, the relative gene expression of the T helper 1 (Th1) cytokine IFN-, the T helper 2 (Th2) cytokine IL-13, the anti-inflammatory cytokines IL-10 and TGF-4 and the pro- inflammatory cytokine IL-17F were determined over a period of 3 weeks in A. galli and non-A. galli-infected chickens. A characteristic Th2 response was observed in the jejunum of A. galli-infected chickens with increased expression of IL-13 and decreased expression of IFN- from day 14 post infection. At the putative time of larvae invasion into the intestinal mucosa (day 7), an increased expression of IFN-, IL-10, and TGF-4 was observed in the spleen. At the putative onset of the innate immune response (day 10), a decreased expres- sion of jejunal IFN- and IL-13 was observed. Finally, at the expected period of an adaptive immune response (days 14-21) a general decreased expression of IFN- and TGF-4 in spleen and IFN- in jejunum was followed by a decreased expression of IFN- and IL-10 at day 21 in caecal tonsils.