"Chicken avian beta-defensin 8 modulates immune response via mitogen-activated protein kinase signaling pathways in a chicken macrophage cell line"

Authors: HONG, Y - Chung-Ang University; PHAM, T - Chung-Ang University; LEE, J - Chung-Ang University; Lillehoj, Hyun; HONG, YH - Chung-Ang University

Submitted to: BMC Veterinary Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/21/2019
Publication Date: 2/11/2020
Citation: Hong, Y., Pham, T.T., Lee, J., Lillehoj, H.S., Hong, Y. 2020. "Chicken avian beta-defensin 8 modulates immune response via mitogen-activated protein kinase signaling pathways in a chicken macrophage cell line". BMC Veterinary Research. https://doi.org/10.21203/rs.2.17721/v2.
DOI: https://doi.org/10.21203/rs.2.17721/v2

Interpretive Summary: Antimicrobial peptides (AMPs) are known to play an important role in innate immunity by killing bacteria, viruses, and fungi.(Reddy, 2004 #92) As a first line of defense, AMPs kill the invading bacteria mainly by disrupting the bacterial cell membrane. Owing to their various mechanisms of action, broad spectrum antimicrobial activities, and immunomodulation effect, AMPs have been actively studied as alternative antibiotic and immune therapy agents. In this study, ARS scientists collaborated with university scientists in South Korea to show the immunomodulation mechanism of avian defensin 8 (AvBD8) and its activation of MAPK signaling pathway. Because the MAPK signaling pathway plays an important role in innate and adaptive immunity and is involved in various cellular functions such as inflammation, cell differentiation, and cell death, this finding will provide background information for future studies on how AvBD8 modulates host immune response when host is infected with pathogens.

Technical Abstract: Background: Defensins are antimicrobial peptides composed of three conserved disulfide bridges, a ß-sheet, and both hydrophobic and cationic amino acids. In this study, we aimed to demonstrate the immunomodulation role of avian ß-defensin 8 (AvBD8) in a chicken macrophage cell line. Results: Chicken AvBD8 stimulated the expression of proinflammatory cytokines (interleukin (IL)-1ß, interferon-', and IL-12p40) and chemokines (CCL4, CXCL13, and CCL20) in macrophages. Furthermore, by western blotting and immunocytochemistry, we confirmed that AvBD8 activated the mitogen-activated protein kinase (MAPK) signaling pathway via extracellular regulated kinases 1/2 (ERK1/2) and p38 signaling molecules. Conclusion: Overall, AvBD8 plays a crucial role in host defense as not only an antimicrobial peptide, but also an immunomodulator by activating the MAPK signaling pathway and inducing the expression of proinflammatory cytokines and chemokines.