Submitted to: Journal of Parasitology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/16/2007
Publication Date: 4/7/2008
Citation: Berezin, V.E., Bogoyavlenskiy, A.P., Tolmacheva, V.P., Makhmudova, N.R., Khudyakova, S.S., Levandovskaya, S.V., Omirtaeva, E.S., Zaitceva, I.A., Tustikbaeva, G.B., Ermakova, O.S., Aleksyuk, P.G., Fetterer, R.H., Barfield, R.C., Danforth, H.D. 2008. Immunostimulating complexes incorporating e. tenella antigens and plant saponins as an effective delivery system for coccidia vaccine immunization. Journal of Parasitology. 94:381-385. Interpretive Summary: Poultry coccidiosis is the result of several different species of a protozoan intestinal parasite which causes considerable annual losses to the poultry industry. The primary control for the disease is through application of medications in the feed as birds are raised in confinement housing. The controls by medications are becoming less effective because of increased resistance to the drugs and less desirable due to concerns about drugs possibly remaining in the meat and within the environment. Vaccination of poultry against coccidiosis with defined antigens is one of the most desirable ways to control the disease but practical vaccines are lacking. Use of novel methods to deliver the vaccine candidate offer promise in the fight against poultry coccidiosis. The current research utilizes a novel vaccine delivery system, immunostimulating complexes (ISCOMs) to vaccinate against poultry coccidiosis. ISCOMs are a unique, multimolecular structure formed by encapsulating antigens, lipids and plant-saponins and have been shown to be an effective delivery system for various kinds of antigens. ISCOMs containing a crude antigen from poultry coccidia caused a greater immune response in vaccinated chickens and mice than by crude antigen alone. The ISCOMs also had low toxicity in both mice and chickens. When chicks were immunized with ISCOMs containing antigens and then infected with coccidian, significant protection was conveyed to chicks compared to immunization with antigen alone. The results of this study indicate that ISCOMs are an effective antigen delivery system which may be successfully used for preparation of highly immunogenic coccidian vaccine with low toxicity.
Technical Abstract: Immunostimulating complexes (ISCOMs) are a unique, multimolecular structure formed by encapsulating antigens, lipids and triterpene saponins of plant origin and are an effective delivery system for various kinds of antigens. The uses of ISCOMs formulated with saponins from plants native to Kazakhstan and with antigens from the poultry coccidian parasite Eimeria tenella were evaluated for their potential in developing a vaccine for coccidiosis. ISCOMs were assembled with saponins isolated from Glycyrrhiza glabra and Aesculus hippocastanum. A greater immune response occurred when chickens and mice were immunized with ISCOMs in comparison with E. tenella antigens alone. Stimulation of IgG, IgA and IgM antibodies by ISCOMs containing saponins of G. glabra and A. hippocastanum was comparable with antibody production after immunization with ISCOMs assembled with the saponin Quil A. Stimulation of INF-gamma, IL-2, IL-4 and IL-10 in mice after subcutaneous immunization with ISCOMs containing Eimeria antigens and saponins of G. glabra and A. hippocastanum was similar to the levels of cytokine induction after immunization with ISCOMs assembled with Quil A and was much higher in comparison with immunization of E. tenella antigens alone. ISCOMs prepared herein had low toxicity in vertebrate systems. When chicks were immunized with ISCOMs prepared with saponins from native plants and E. tenella antigens and then challenged with E. tenella oocysts, significant protection was convey to chicks compared to immunization with antigen alone. The results of this study indicate that ISCOMs formulated with saponins isolated from plants indigenous to Kazakhstan are an effective antigen delivery system which may be successfully used for preparation of highly immunogenic coccidia vaccine with low toxicity.