|HONG, J - Chung-Ang University|
|LEE, J - Chung-Ang University|
|VU, TH - Chung-Ang University|
|HONG, YH - Chung-Ang University|
Submitted to: Research in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/12/2020
Publication Date: 6/1/2020
Citation: Hong, J., Lee, J., Vu, T., Lillehoj, H.S., Hong, Y. 2020. Immunomodulatory effects of avian ß-defensin 5 in chicken macrophage cell line. Research in Veterinary Science. https://doi.org/10.1016/j.rvsc.2020.06.002.
Interpretive Summary: Host defensins are antimicrobial peptides which host produces to fight infections and can mediate direct killing of pathogens. In this study, ARS scientists collaborated with scientists in South Korea and showed that new chicken defensin protein called Avian Beta Defensin 5 (AvBD 5) can kill pathogens and contains six conserved cysteine forming three disulfide bonds. Chickens have only ß-defensins and most chicken AvBDs have antimicrobial properties against pathogenic bacteria and fungi. The antimicrobial mechanism of AvBD is thought to be similar with most antimicrobial peptides (AMPs) and involves disrupting bacterial cell membrane. In this report, recombinant AvBD5 protein was produced and its effects on immune cells were studied. The results showed that chicken AvBD5 protein induced various cytokines of T lymphocytes in chicken macrophage cell line and regulated signaling pathways associated with innate immune systems. This information will enhance our understanding of various defense mechanisms that chickens use against pathogens.
Technical Abstract: Objective: In this study, we characterized chicken AvBD5 and demonstrated its immune modulatory functions in chicken macrophage cell line (HD11). Methods: AvBD5 was cloned to pCR2.1 and pET32a from Gallus gallus AvBD5 mRNA sequence. AvBD5 recombinant protein was extracted with B-PER and purified using HisPur Cobalt Resin. Chicken macrophage cell line (HD11) were treated with AvBD5 recombinant protein for quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and immunocytochemistry (ICC). Results: Chicken AvBD5 is composed of signal, pro, and mature peptides containing one a-helix, four ß-sheet, and three disulfide bonds. Here, we also showed that chicken AvBD5 induced Th1, Th2, and Th17 cytokines in chicken macrophage cell line and stimulated MAPK signaling pathways through ERK1/2 and p38 molecules. In addition, AvBD5 stimulated MyD88 and CD40 to regulate immune systems. Conclusion: Chicken AvBD5 can modulate host immune systems by inducing cytokines expression and stimulating MAPK signaling pathway.