Submitted to: Coccidiosis International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 5, 2005
Publication Date: September 15, 2005
Citation: Hong, Y.H., Lillehoj, H.S., Dalloul, R.A., Miska, K.B., Lee, S.H. 2005. Molecular cloning and expression profiles of chicken nk-lysin during eimeria infections.. Coccidiosis International Conference Proceedings, p. 153.
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 Eimeria maxima, chicken total IELs, CD4+, and CD8+ IELs showed higher expression levels of NK-lysin mRNA than other IEL subpopulations. Upon infections with three Eimeria species, chicken NK-lysin RNA expression level to GAPDH showed differential and interesting patterns. Chicken NK-lysin was expressed into COS-7 cells and its antitumor activity was demonstrated in killing LSCC-RP9 macrophage transformed cells. Further, chicken NK-lysin has sequence similarity to other mammalian cDNA with cytotoxic activity to tumor cells. In these studies, we have 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 and salmonella, especially at the early stages of such infections.