ARS | Publication request: Construction and Application of an Avian Intestinal Intraepithelial Lymphocyte cDNA Microarray for Gene Expression Profiling during Eimeria maxima Infection

Submitted to: Molecular Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 20, 2008
Publication Date: June 20, 2008
Citation: Kim, Chul, H., Lillehoj, H.S., Bliss, T.W., Keeler, C.L., Hong, Y.H., Park, Dong, W., Yamage, M., Lillehoj, E.P., Min, W. 2008. Construction and Application of an Avian Intestinal Intraepithelial Lymphocyte cDNA Microarray for Gene Expression Profiling during Eimeria maxima Infection. Molecular Immunology. 124:341-354.

Interpretive Summary: Avian coccidiosis is a major parasitic disease of poultry caused by the apicomplexan protozoa Eimeria. Coccidiosis seriously impairs the growth and feed utilization of infected birds resulting in loss of productivity in excess of $3 billion annually world-wide. Conventional disease control strategies rely heavily on chemoprophylaxis and, to a certain extent, immunization with live vaccines. However, increasingly restrictive governmental regulation of anticoccidial drugs and the high costs of new drug/vaccine development have stimulated the need for novel and alternative control strategies against coccidiosis. In this paper, ARS scientists collaborated with scientists at University of Delaware and University of Maryland to develop molecular genomics technology to investigate local host-pathogen interactions in the gut during infection with Eimeria parasites. Using a new chicken intestinal cDNA microarray chip, these investigators demonstrated that chicken intestinal IELs and their cytokines generated during a primary immune response against Eimeria protozoa are principally responsible for protective immunity against subsequent secondary infections. The results of this study provide fundamental knowledge on coccidiosis immunity which will be critical for the development of new alternative control method against avian coccidiosis.

Technical Abstract: Intestinal intraepithelial lymphocytes (IELs) are the primary immune effector cells in the gut and play a critical role in eliciting protective immunity to enteric pathogens such as Eimeria, the etiologic agent of avian coccidiosis. In this study, a library of genes expressed by intestinal IELs of Eimeria-infected chickens was constructed using the expressed sequence tag (EST) strategy and was used to analyze gene expression profiles during primary or secondary Eimeria maxima infections. The chicken intestinal IEL cDNA array contained duplicates of 9,845 individual ESTs, of which 5,559 contained at least one replicate spot that provided high quality, analyzable data. Following primary infection with E. maxima, the expression levels of 75 genes were significantly altered at days 1, 2, or 3 post-infection compared with the day 0 uninfected controls. Of these genes, 52 were up-regulated and 23 were down-regulated. Following secondary infection, the expression levels of 308 genes were significantly altered (62 up-regulated, 246 down-regulated). Gene function analysis indicated that some of the modulated genes were related to innate and adaptive immune responses (interleukin signaling, TLR signaling, antigen presentation, apoptosis). This chicken IEL microarray will provide a valuable resource for future expression profiling of the genes involved in protective immunity to enteric pathogen-infected chickens.