Contributed Papers: Oral Presentations Immunology |
Application of
functional genomics, immunology and molecular biology
tools to explore host immune response to Eimeria.
Lillehoj1, H. S., Dalloul1, R. A., Hong1,
Y. H., Bliss2, T. W., Keeler2, C. L., Ben Chouikha1,
I., Park1, D.W., and Han3, J.Y. Animal Parasitic Diseases
Laboratory1, Animal and Natural Resources Institute,
U.S. Department of Agriculture, Beltsville, MD. 20705,
Department of Animal and Food Sciences2, University
of Delaware, Newark, DE., School of Agricultural Biotechnology3,
Seoul National University, Seoul 151-742, Korea (email
address of presenting author: hlilleho@anri.barc.usda.gov)
Avian coccidiosis
is caused by several different Eimeria species which
infect different regions of the intestine inducing
a specie-specific immunity. Coccidiosis usually stimulates
a number of immunological defense mechanisms, namely
antibody- and cell-mediated. Recent technological
advance in molecular genomics is opening a novel way
for the discovery of molecular/cell biological pathways
associated with complex biological phenomenon and
is facilitating the development of an alternative
strategy to combat coccidiosis. Using high-throughput
molecular genomics approaches, we have identified
host genes involved in the disease process and resistance.
Since intraepithelial lymphocytes (IELs) play a critical
role in protective immune response to Eimeria, a list
of genes expressed by intestinal IEL of Eimeria-infected
chickens was compiled using the expressed sequence
tag (EST) strategy. The 14,409 ESTs consisted of 1,851
clusters and 7,595 singletons, which revealed 9,446
unique genes in the data set. This EST library will
be a valuable resource for profiling global gene expression
in normal and pathogen-infected chickens for the identification
of host immune-related genes. We have also carried
out fine mapping of quantitative trait locus (QTL)
which control coccidiosis resistance and identified
a QTL on chromosome 1 that significantly affects Eimeria
oocyst shedding and three QTLs that influence body
weight of chickens during coccidiosis. These results
provide the foundation for further investigation to
validate the QTL. In addition, we have investigated
local host immunity to Eimeria using tissue-specific
cDNA microarrays. The results of these studies clearly
indicate that the intricate and complex interactions
of host local innate immune response and parasites
determine the outcome of host response to coccidiosis.