Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: March 24, 2008
Publication Date: April 23, 2008
Citation: Hong, Y.H., Lillehoj, H.S., Siragusa, G.R., Bannerman, D.D. 2008. Novel anti-microbial peptide, nk-lysin, is produced locally in the gut of eimeria-infected host. BARC Poster Day.April 23, Beltsville, MD. P 18.
NK-lysin is an anti-microbial and anti-tumor protein produced by NK cells and T lymphocytes in mammals and is considered to be an important component of the local innate immune response to pathogens. Chicken NK-lysin consists of an 868 bp DNA sequence with an ORF of 140 amino acids with a predicted molecular mass of 15.2 kDa. Comparison of its deduced amino acid sequence showed less than 20% identity to the mammalian NK-lysin. Chicken NK-lysin also is a member of the saposin-like protein family with potent antimicrobial activity. To evaluate the biological role of chicken NK-lysin, we expressed biologically active recombinant NK-lysin and examined its antimicrobial activity against various bacterial strains, tumor cell lines and 3 major Eimeria spp. in chickens. Recombinant chicken NK-lysin expressed in COS7 cells and purified as His-tagged NK-lysin exhibited potent anti-tumor cell activity against LSCC-RP9, retrovirus-transformed B-cell line and direct cytotoxicity against E. acervulina and E. maxima sporozoites. Interestingly, unlike mammalian NK-lysins, the chicken counterpart did not show cytotoxic activity against a number of bacteria strains. Further studies using synthetic peptides of chicken NK-lysin will lead to better insights on the mechanism of anti-microbial activity of NK-lysin and a potential application of this protein in the pharmaceutical agricultural industry. Supported by USDA CSREES No. 1265-31320-072-00D.