|Ben Chouikha, Imed|
|Keeler Jr, Calvin|
Submitted to: Molecular Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2006
Publication Date: 2/5/2007
Citation: Dalloul, R.A., Bliss, T.W., Hong, Y.H., Ben Chouikha, I., Park, D., Keeler Jr, C.L., Lillehoj, H.S. 2007. Unique Responses of the Avian Macrophage to Different Species of Eimeria. Molecular Immunology 44:558-566. Interpretive Summary: Coccidiosis is recognized as the major parasitic disease of poultry and is caused by the apicomplexan protozoa Eimeria. Coccidiosis seriously impairs the growth and feed utilization of infected birds resulting in loss of productivity and it inflicts economic losses in excess of $3 billion annually to the world poultry industry. Conventional disease control strategies rely heavily on chemoprophylaxis and to a certain extent on live vaccines. Increasing regulations and bans on the use of anticoccidial drugs coupled with the associated cost for developing new drugs and live vaccines have stimulated the need for developing novel approaches and alternative control strategies for coccidiosis. However, such new approaches will only be realized after a systematic and detailed analysis of host-parasite interactions at the molecular and cellular levels is completed. In this paper, new molecular genomics technology was applied to investigate immunological response of poultry to avian coccidia, causative agent of coccidiosis. Furthermore, high-throughput gene expression analysis of host immune response to coccidiosis was analyzed for the first time using chicken macrophage cDNA microarray which contains 4,906 unique gene elements isolated from avian macrophages. This approach enabled us to identify common genetic elements whose transcriptional expression are induced by exposure to Eimeria sporozoites and to identify transcription patterns unique to an individual Eimeria species. Information gained from this investigation will enhance our ability to develop novel control method against avian coccidiosis.
Technical Abstract: Coccidiosis is recognized as the major parasitic disease of poultry and is caused by the apicomplexan protozoa Eimeria. Increasing evidence shows the complexity of the host immune response to Eimeria and microarray technology presents a powerful tool for the study of such an intricate biological process. Using an avian macrophage microarray containing 4,906 unique gene elements, we identified important host genes whose expression changed following infection of macrophages with sporozoites of E. tenella, E. acervulina, and E. maxima. This approach enabled us to identify a common core of 25 genetic elements whose transcriptional expression is induced or repressed by exposure to Eimeria sporozoites and to identify additional transcription patterns unique to each individual Eimeria species. Besides inducing the expression of IL 1, IL 6, and IL 18 and repressing the expression of IL 16, Eimeria treated macrophages were commonly found to induce the expression of the CCL chemokine family members MIP 1 (CCLi1), K203 (CCLi3), and ah221 (CCLi7). However, the CXCL chemokine K60 (CXCLi1) was found to be induced by macrophage exposure to E. tenella but was repressed upon macrophage exposure to E. maxima and E. acervulina. Fundamental analysis of avian chemokine and cytokine expression patterns offers insight into the unique avian immunological responses to these related but biologically unique pathogens.