Equus β-Defensin-1 Regulates Innate IMMUNE Response in S. aureus-Infected Mouse Monocyte Macrophage

• Published in: Animals (Basel) Vol. 12; no. 21; p. 2958
• Main Authors: Pei, Le, Liu, Kun, Wei, Wei, Su, Hong, Li, Feng, Feng, Ying, Wang, Daqing, Li, Xiunan, Hou, Yongyue, Cao, Guifang
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 27.10.2022; MDPI
• Subjects: Amino acids; Antibacterial activity; Antibiotics; Cell culture; Cloning; CXCL10 protein; Cytokines; Defensins; Disulfide bonds; E coli; Enzymes; Equus; Gene expression; IL-1β; Immune response; Immune system; Innate immunity; Interleukin 6; Kinases; Language; Macrophages; Mammals; Monocyte chemoattractant protein 1; Monocytes; NF-κB protein; Open reading frames; Peptides; Phosphorylation; Proteins; S. aureus-infected; Signal transduction; Spleen; Stimulation; Syk protein; Tissues; TLR2 protein; Toll-like receptors; Tumor necrosis factor-α; β-defensin-1; United States > US; Mongolia; China
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani12212958

Beta-defensin-1 (BD-1) is among the class of antibacterial peptides that are rich in disulfide bonds, have direct antibacterial activity and showed enhanced expression following external stimulation. However, existing research studies only treated BD-1 to cell models without stimulation from pathogen-associated molecular patterns (PAMPs), which will further influence our understanding of the role of BD-1. In this study, we map the tissue distribution of Equus BD-1 (i.e., eBD-1, ass BD-1, and mule BD-1) and compare their expression levels in various tissues. We further characterize the three kinds of Equus BD-1 by analyzing their full-length cDNA. We showed that eBD-1, ass BD-1, and mule BD-1 have an identical (100%) open reading frame (ORF). The ORF encoding OEBD-1 expressed the ORF in the E. coli Top10 expression system. This expression system was combined with an S. aureus-infected J774A.1 macrophage cell line to determine the influence on innate immune mediator expression. Using this expression model system, it was determined that the OEBD-1 protein enhanced IL-6 and TNF-α secretion. It can also promote TLR2, IL-1β, CCL2, CCL7, CXCL10 and NF-κB p65 mRNA expression. Moreover, OEBD-1 upregulates phosphorylation of ATK, Syk and IκB-α. In addition, OEBD-1 enhances the macrophage’s ability to phagocytose S. aureus. In conclusion, Equus BD-1 was shown to play an essential role in macrophage-involved innate immune responses in an in vitro system.