Production and characterisation of recombinant antigens of Eimeria and their potential use in a maternally-delivered vaccine against poultry coccidiosis

Funding: 1998: $98,000
1999: $101,000
2000: $104,000

Project Member(s): Wallach, M.

Funding or Partner Organisation: Australian Research Council (ARC SPIRT (Strategic Partnerships with Industry Re)
Abic Biological Laboratories Teva Ltd (Abic Ltd)

Start year: 1998

Summary: Coccidiosis, caused by the protozoan parasite Eimeria is a major pathogenic disease of poultry worldwide. Young chickens are protected against Eimeria by the transfer of antibodies from their mothers into the egg yolk, which is absorbed by hatchlings. We used these maternal antibodies to identify proteins for inclusion in a vaccine. We now aim to produce and characterise these proteins using recombinant DNA technology and to formulate a subunit vaccine that is administered to breeding hens to protect their hatchlings via maternal antibodies. Such a vaccine will reduce the costs associated with chemoprophylaxis and allow production of residue-free meat. The aim of this research is to facilitate development of second generation maternally-delivered vaccines against coccidiosis, caused by parasites in the genus Eimeria, in chickens by : (1) producing recombinant versions of putative subunit vaccine candidates from Eimeria maxima including a 230 kDa merozoite protein, a 230 kDa gametocyte protein, an 82 kDa gametocyte protein and a 56 kDa gametocyte protein; (2) exploring the potential molecular relationships between these proteins; (3) determining the importance of glycosylation of these proteins for induction of maternal immunity; (4) determining how the genes encoding these antigens are organised and expressed in the genome and whether they undergo antigenic variation or diversification; (5) assessing whether combination immunoprophylaxis (eg vaccination with merozoite and gametocyte antigens) is more efficacious than vaccination with antigens from one developmental stage alone.

Publications:

Belli, SI, Wallach, MG & Smith, NC 2003, 'Cloning and characterization of the 82 kDa tyrosine-rich sexual stage glycoprotein, GAM82, and its role in oocyst wall formation in the apicomplexan parasite, Eimeria maxima', Gene, vol. 307, no. 1-2, pp. 201-212.
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Belli, SI, Wallach, MG, Luxford, C, Davies, MJ & Smith, NC 2003, 'Roles of Tyrosine-Rich Precursor Glycoproteins and Dityrosine- and 3,4-Dihydroxyphenylalanine-Mediated Protein Cross-Linking in Development of the Oocyst Wall in the Coccidian Parasite Eimeria maxima', Eukaryotic Cell, vol. 2, no. 3, pp. 456-464.
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Ferguson, DJP, Belli, SI, Smith, NC & Wallach, MG 2003, 'The development of the macrogamete and oocyst wall in Eimeria maxima: immuno-light and electron microscopy', International Journal for Parasitology, vol. 33, no. 12, pp. 1329-1340.
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Witcombe, DM, Belli, SI, Wallach, MG & Smith, NC 2003, 'Molecular characterisation of EmTFP250: a novel member of the TRAP protein family in Eimeria maxima', International Journal for Parasitology, vol. 33, no. 7, pp. 691-702.
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Belli, SI, Lee, M, Thebo, P, Wallach, MG, Schwartsburd, B & Smith, NC 2002, 'Biochemical characterisation of the 56 and 82 kDa immunodominant gametocyte antigens from Eimeria maxima', International Journal for Parasitology, vol. 32, no. 7, pp. 805-816.
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Belli, SI, Witcombe, D, Wallach, MG & Smith, NC 2002, 'Functional genomics of gam56: characterisation of the role of a 56 kilodalton sexual stage antigen in oocyst wall formation in Eimeria maxima', International Journal for Parasitology, vol. 32, no. 14, pp. 1727-1737.
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Keywords: Eimeria; coccidiosis; protozoa; chickens; immunity; vaccines

FOR Codes: Molecular Cell Biology, Animal Protection (Pests and Pathogens), Immunology, Prevention - biologicals (e.g. vaccines), Biological sciences, Biochemistry and Cell Biology, Animal protection (incl. pests and pathogens)