Dietary oils modulate T-cell differentiation and IL-2 bioactivity of intestinal mucosal lymphocytes in chickens

Abstract

The study was conducted to investigate the effects of dietary oils on the differentiation of intestinal lymphocytes and cytokines generation in chickens. One hundred and eighty chickens were assigned to three groups in one factorial design. Factor was dietary fat types (4.5% poultry oil, 4.5% corn oil or 4.5% fish oil). The proportion of CD3+CD4+ lymphocytes of intestinal mucosal lymphocytes (IMLs) in chickens fed fish-oil diets on 21 d and 42 d of age was significantly higher than those in chickens fed corn-oil and poultry-oil diets (P <0.01). And the proportion of intestinal CD3+CD8+ lymphocytes of chickens fed fish-oil diets was significantly lower than those of chickens fed corn-oil and poultry-oil diets (P <0.01) on 21 d and 42 d of age. Fish-oil consumption enhanced IL-2 secretion of IMLs stimulated with concanavalin A (ConA) (P <0.01), compared with poultry oil; but corn-oil consumption decreased IL-2 secretion than poultry-oil diets (P <0.01). Fish oil decreased the mRNA abundance of calcitonin gene-related peptide (cGRP) in intestinal mucosa of chickens on 21 d and 42 d of age compared to poultry oil (P <0.01). Corn oil increased the mRNA abundance of cGRP compared to poultry oil (P <0.01). Compared with group fed corn-oil or poultry-oil diets, IMLs had lower concentration of cAMP and lower bioactivity of adenylyl cyclase (AC) of chickens supplemented with fish oil on 21 d and 42 d of age. Meanwhile, corn oil increased cAMP level and AC bioactivity. Taken together, these data show a modulatory role for cGRP in the interaction between different type of oils and T-cell differentiation and IL-2 bioactivity of IMLs in chickens, which suggests that AC and cAMP signalling involved the intestinal mucosal immune responses.