Submitted to: Biotechnology Letters
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/9/2005
Publication Date: 3/1/2005
Citation: Park, K., Park, D., Kim, C., Han, B.K., Park, T.S., Han, J.Y., Lillehoj, H.S., Kim, J.K. 2005. Development and characterization of a recombinant chicken single-chain fv antibody detecting eimeria acervulina sporozoite antigen.Biotechnology Letters. 27:289-295. Interpretive Summary: Avian coccidiosis, caused by intestinal parasites belonging to the genus Eimeria, results in a significant economic loss to the poultry industry worldwide. Although anti-coccidial drugs have been effective for the control of this disease, high costs and the increasing emergence of drug resistant parasites limit their use in the field. As an alternative strategy, vaccination using whole parasites has shown to induce strong protective host immunity against coccidiosis. However, due to the complexity of the parasite life cycle and the existence of multiple species of Eimeria, host protective immunity induced by live parasite vaccines is limited and do not protect against field variants of Eimeria. In this paper, ARS scientists in collaboration with scientists at Seoul National University and Changwon University developed a new immunological strategy which involves using antibodies that actively block the invasion of parasites into host cells. Using recombinant chicken antibodies designed to block parasite invasion of cells, these scientists propose a new intervention strategy to reduce coccidian contamination in the field. This is the first demonstration that show feasibility of using recombinant chicken antibodies to reduce coccidia infection. This information will help poultry industry to develop a new method to control avian coccidiosis.
Technical Abstract: Chicken monoclonal antibody (mAb), 8C3, which is reactive with a sporozoite antigen of Eimeria acervulina, is a potential therapeutic agent against avian coccidiosis caused by Eimeria spp. However, production of it in cell culture requires improvement. Accordingly, recombinant single chain variable fragment (ScFv) antibody was constructed by amplification of the VH and VL genes from chicken hybridoma, 8C3 and when expressed in E. coli gave 5 mg l-1 antibody . The expressed protein had antigen binding activity equivalent to that of the parental mAb. In addition, nucleotide sequence comparison to the germline chicken VL suggested that the gene conversion with V lambda pseudogenes might contribute to the diversification of VL genes in chickens. Recombinant 8C3 antibody represents a valuable resource for avian immunology and parasitology.