Characterisation of basal expression of selected cytokines in the liver, spleen, and respiratory, reproductive and intestinal tract of hens

Abstract

In this study we investigated the basal expression of chicken IFNγ, IL-18, IL-1β, LITAF, IL-12p35, IL-12p40, iNOS, IL-17, IL-15, IL-6, IL-8 and IL-22 in the ileum, caecum, colon, liver, spleen, lungs, blood and magnum of hens using real time PCR. We show that IL-18, LITAF and IL-15 were highly expressed in most tissues while IL-6 and IL-17 were usually expressed at a low level. IL-17 and IL-22 were expressed mainly in the lungs and intestinal tract and both subunits of IL-12 were produced in the liver. Unusually high expression of iNOS was observed in the blood which may explain the rapid increase in iNOS at inflamed sites in chickens. The second unexpected expression profile was that of IL-18 and IL-6 in magnum. These two cytokines were highly expressed in magnum in the absence of any infection pointing to an important, though as yet uncharacterised, physiological role in the reproductive tract of hens.