The immunomodulatory effect of cathelicidin-B1 on chicken macrophages

Veterinary Research

Roel M. van Harten¹  Edwin J. A. Veldhuizen¹  Lianci Peng¹  Henk P. Haagsman¹  Maaike R. Scheenstra¹ 

[1] Department of Biomolecular Health Sciences, Division of Infectious Diseases & Immunology, Section of Molecular Host Defence, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584CL, Utrecht, The Netherlands;

关键词: chicken;    innate immunity;    macrophages;    antimicrobial peptides;    cathelicidins;    E. coli;   

DOI  :  10.1186/s13567-020-00849-y

来源: Springer

【 摘 要 】

Cathelicidins (CATHs) play an important role in the innate immune response against microbial infections. Among the four chicken cathelicidins, CATH-B1 is studied the least. In this study, the effect of CATH-B1 on the macrophage response towards avian pathogenic E. coli (APEC) and bacterial ligands was investigated. Our results show that APEC induced CATH-B1 gene expression in both a chicken macrophage cell line (HD11 cells) and primary macrophages, while expression of the other three CATHs was virtually unaffected. While the antimicrobial activity of CATH-B1 is very low under cell culture conditions, it enhanced bacterial phagocytosis by macrophages. Interestingly, CATH-B1 downregulated APEC-induced gene expression of pro-inflammatory cytokines (IFN-β, IL-1β, IL-6 and IL-8) in primary macrophages. In addition, CATH-B1 pre-incubated macrophages showed a significantly higher gene expression of IL-10 after APEC challenge, indicating an overall anti-inflammatory profile for CATH-B1. Using isothermal titration calorimetry (ITC), CATH-B1 was shown to bind LPS. This suggests that CATH-B1 reduces toll like receptor (TLR) 4 dependent activation by APEC which may partly explain the decreased production of pro-inflammatory cytokines by macrophages. On the contrary, direct binding of CATH-B1 to ODN-2006 enhanced the TLR21 dependent activation of macrophages as measured by nitric oxide production. In conclusion, our results show for the first time that CATH-B1 has several immunomodulatory activities and thereby could be an important factor in the chicken immune response.

【 授权许可】

CC BY