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Contributed Papers: Oral Presentations Immunology |
Molecular cloning and expression profiles of chicken
NK-lysin during Eimeria infections
Yeong
H. Hong*, Hyun S. Lillehoj#,
Rami A. Dalloul, Kate B. Miska, Wenbin Tuo, and Sung
H. Lee
Animal Parasitic Diseases Laboratory, Animal and Natural
Resources Institute, USDA-ARS, Beltsville, MD 20705,
USA
ABSTRACT
NK-lysin is known to have antibacterial and antitumor
activities and is expressed by NK cells as well as
T-lymphocytes. In a previous report, the contig 171
(NK-lysin-like sequence), composed of 87 ESTs, occurred
with the highest prevalence in an Eimeria-induced
intestinal cDNA library. This study was conducted
to clone, express, and characterize contig 171 as
the chicken NK-lysin, which consists of an 868 bp
DNA sequence and an open reading frame of 140 amino
acids with a predicted molecular mass of 15.2 kDa.
Comparison of deduced amino acid sequences showed
less than 20% identity to granulysin and other mammalian
NK-lysins. When infected with E. maxima, chicken total
intraepithelial lymphocytes (IELs), CD4+ and CD8+
IELs showed higher expression levels of NK-lysin mRNA
than CD8- IELs as quantified by real-time PCR. Upon
infections with three Eimeria species, chicken NK-lysin
RNA expression level normalized to GAPDH exhibited
differential and interesting patterns. Further, chicken
NK-lysin was expressed into COS-7 cells and its antitumor
activity was demonstrated in killing LSCC-RP9 macrophage
transformed cells. Also, chicken NK-lysin showed sequence
similarity to other mammalian cDNA with cytotoxic
activity to tumor cells. In these studies, we cloned
and characterized chicken NK-lysin and studied its
expression patterns in mRNA of Eimeria-infected birds.
As in other animals, chicken NK-lysin may play an
important role in antimicrobial defenses against enteric
pathogens such as Eimeria, especially at the early
stages of such infections.
*Presenting Author
#Corresponding Author
E-mail: hlilleho@anri.barc.usda.gov
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