Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 25, 2011
Publication Date: August 26, 2011
Citation: Lee, S.H., Lillehoj, H.S., Jang, S., Lee, K., Bravo, D., Lillehoj, E.P. 2011. Effects of dietary supplementation with phytonutrients on vaccine-stimulated immunity against infection with Eimeria tenella. Veterinary Parasitology. 181:97-105. Interpretive Summary: Due to increasing governmental regulation on the use of antibiotics in poultry production, there is a timely need to develop alternative strategies to control infectious diseases of economic important. In this paper, ARS scientists evaluated two commercially available plant-derived phytonutrient mixtures, VAC (carvacrol, cinnamaldehyde, and Capsicum oleoresin), and MC (Capsicum oleoresin and turmeric oleoresin), for their effects on eliciting local and systemic immune responses following immunization of chickens with an Eimeria recombinant protein. The results of these studies showed for the first time that dietary feeding of young broilers with diets supplemented with VAC or MC show enhanced body weight gains compared to control chickens which were fed standard non-supplemented diet. Furthermore, immunized chickens given the MC-supplemented diet demonstrated increased serum antibody levels and greater lymphocyte proliferation response compared with non-supplemented controls. These results indicate that dietary supplementation of young birds with the plant-derived phytonutrients can improve host innate immunity and be effectively used to mitigate the negative effects of infectious disease in poultry.
Technical Abstract: Two phytonutrient mixtures, VAC (carvacrol, cinnamaldehyde, and Capsicum oleoresin), and MC (Capsicum oleoresin and turmeric oleoresin), were evaluated for their effects on local and systemic immune responses following immunization of chickens with an Eimeria recombinant protein. Chickens were fed from hatch with a non-supplemented diet, or with diets supplemented with VAC or MC, animals were immunized subcutaneously with profilin at 7 days post-hatch, and orally challenged with virulent oocysts of E. tenella at 17 days post-hatch. Immunity against infection was evaluated by (a) body weight gain, (b) fecal oocyst shedding, (c) anti-profilin serum antibody levels, (d) splenic lymphocyte profilin recall responses, (e) intestinal levels of cytokine gene transcripts, and (f) peripheral blood lymphocyte subpopulations. Profilin-immunized and Eimeria-infected chickens fed the VAC- or MC-supplemented diets had increased body weight gains compared with immunized and infected animals given the non-supplemented diet. However, fecal oocyst shedding was not affected in the experimental vs. control groups. Immunized chickens given the MC-supplemented diet displayed increased anti-profilin antibody levels and greater profilin-induced lymphocyte proliferation compared with non-supplemented controls. Anti-profilin antibody levels, but not cell proliferation, were increased in birds given the VAC-supplemented diet. Prior to Eimeria infection, immunized chickens fed the MC-supplemented diet had reduced levels of IFN-' and IL-6 mRNAs, and increased expression of TNFSF15, compared with non-supplemented controls. Interestingly, post-infection levels of IFN- ' and IL-6 were increased, while IL-17F transcripts were decreased, with MC-supplementation. For VAC-supplemented diets, decreased levels of transcripts for IL-17F and TNFSF15 compared with non-supplemented controls were observed only in infected chickens. Finally, immunized chickens fed the MC-supplemented diet exhibited increased percentages of MHC class II+, CD4+, CD8+, TCR1+, and TCR2+ lymphocytes compared with non-supplemented controls, while animals given the VAC containing diet only displayed an increase in K1+ macrophages. In conclusion, this study documents the immune molecular and cellular changes following phytonutrient dietary supplementation that are relevant to protective immunity following recombinant protein vaccination against avian coccidiosis. Keywords: food supplements, chicken, coccidiosis, cell-mediated immunity, cytokine Abbreviation: GAPDH = glyceraldehyde 3-phosphate dehydrogenase; HBSS = Hank's balanced salt solution; IFN = interferon; IL = interleukin; mAb = monoclonal antibody; MHC = major histocompatibility complex; PBL = peripheral blood lymphocyte; PBS-T = phosphate-buffered saline containing 0.05% Tween; TCR = T cell receptor; TNFSF15 = tumor necrosis factor super family 15; F = forward primer; R = reverse primer