Submitted to: Developmental and Comparative Immunology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/15/2010
Publication Date: 4/5/2010
Citation: Kim, C., Lillehoj, H.S., Hong, Y., Lillehoj, E., Keeler, C.L. 2010. Comparison of Global Transcriptional Responses of Chicken Following Primary and Secondary Eimeria acervulina Infections. Developmental and Comparative Immunology. 34:344-351. Interpretive Summary: The apicomplexan protozoa Eimeria cause avian coccidiosis, a major parasitic disease of poultry. Conventional disease control methods have relied on chemoprophylaxis with anti-coccidia drugs or immunization with vaccines, however, novel strategies are sought due to governmental restrictions on the commercial use of coccidiostats, the emergence of drug resistant parasites, and the high costs of new drug/vaccine development. Using large-scale functional analysis of chicken genomics by high throughput DNA microarray technology, ARS scientists in collaboration with University of Delware scientists conducted a thorough investigation of complex transcription patterns to analyze intricate biological systems in host-parasite interactions during coccidiosis.. Infection with E. acervulina, which infects the duodenum, showed that significant modulation in transcript levels for gene related to energy metabolism and immunity occurred following parasite infection which can explain various pathological changes associated with intracellular infection caused by Eimeria. This study provides background information for the development of future immunological strategies to reduce economic losses due to coccidiosis.
Technical Abstract: In the current study, we compared chicken gene transcriptional profiles following primary and secondary infections with Eimeria acervulina using a 9.6K avian intestinal intraepithelial lymphocyte cDNA microarray (AVIELA). Gene Ontology analysis showed that primary infection significantly modulated the levels of mRNAs for genes involved in the metabolism of lipids and carbohydrates as well as those for innate immune-related genes. By contrast, secondary infection increased the levels of transcripts encoded by genes related to humoral immunity and reduced the levels of transcripts for the innate immune-related genes. Because the observed modulation in transcript levels for gene related to energy metabolism and immunity occurred concurrent with the clinical signs of coccidiosis, these results suggest that altered expression of a specific set of host genes induced by Eimeria infection may be responsible, in part, for the observed reduction in body weight gain and inflammatory gut damage that characterizes avian coccidiosis.