Contributed Papers: Oral Presentations Immunology |
Common and Unique Gene Expression of Avian Macrophages
in Response to Three Major Eimeria Species
Rami A. Dalloul,1,* Hyun
S. Lillehoj1,# Travis W. Bliss,2 Yeong-Ho Hong1 and
Calvin L. Keeler2
1Animal Parasitic Diseases Laboratory, Animal and
Natural Resources Institute, USDA-ARS, Beltsville,
MD 20705, USA
2Department of Animal and Food Sciences, College of
Agriculture and Natural Resources, University of Delaware,
Newark, DE 19716, USA
ABSTRACT
Host immune responses to Eimeria are very complex
and involve both innate and adaptive immunities. The
chicken intestine is an intricate and dynamic ecosystem
where immune elements interact with antigenic components
of pathogens as well as with those of nutrients, exogenous
compounds and microflora. These immune responses are
also influenced by the host genetic makeup and their
interactions are essential in the defense against
enteric pathogens like Eimeria. The outcomes of these
complex interactions determine resistance to infection,
and the development of genomic tools and techniques
allows for analysis of such multiple and complex host
responses. Macrophages and intraepithelial lymphocytes
(IELs) are critical components of the intestinal immune
system and have been shown to play significant roles
in both the innate and acquired immune responses to
Eimeria. In order to better understand the immunobiology
of host-parasite interaction, avian macrophage and
IEL cDNA microarrays were used. Using avian macrophage
microarray containing 4,906 unique gene elements obtained
from chicken macrophage cDNA library and spotted in
triplicates, we identified important host genes which
expression were enhanced following infection of macrophages
with sporozoites of E. tenella, E. acervulina, and
E. maxima. Genes which showed significant expression
were confirmed using real-time quantitative PCR. Host
genes, which expression changed significantly after
infection with Eimeria, included many genes encoding
cytokines and chemokines that are associated with
inflammatory responses. Among key cytokine genes that
increased shortly after infection IFN-g, IL-2, IL-15,
IL-16 IL-17, and IL-18 were included. Furthermore,
we prepared a cDNA library from intestinal IELs of
Eimeria-infected chickens and constructed a small
intestinal microarray containing over 10,000 unique
elements spotted in duplicates. Investigations are
currently under way to study kinetic gene expression
in mucosal scrapings of birds infected by one of the
three Eimeria species. Further analysis of these expression
patterns will contribute to a better understanding
of the mechanisms underlying resistance and susceptibility
to coccidiosis.
*Presenting author
#Corresponding author: hlilleho@anri.barc.usda.gov