An l-rhamnose-binding lectin from Nile tilapia (Oreochromis niloticus) possesses agglutination activity and regulates inflammation, phagocytosis and respiratory burst of monocytes/macrophages. (January 2022)

• Record Type: Journal Article
• Authors: Mu, Liangliang; Yin, Xiaoxue; Qi, Weiwei; Li, Jiadong; Bai, Hao; Chen, Nuo; Yang, Yanjian; Wang, Bei; Ye, Jianmin
• Is Part Of: Developmental and comparative immunology. Volume 126(2022)
• Publication Date: 2022-01
• Subjects: Oreochromis niloticus -- l-rhamnose-binding lectin -- Agglutination -- Non-specific cell immunity -- Monocytes/macrophages; Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2021.104256
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: Rhamnose-binding lectins (RBLs), a Ca 2+ -independent lectin family, are widely present in vertebrates and invertebrates, which involve in the innate immune response. However, the functional characterization and related regulation mechanisms of RBLs remain unclear in teleost fish. In this study, an l -rhamnose-binding lectin-like (OnRBL-L) was identified and functionally characterized from Nile tilapia ( Oreochromis niloticus ). The open reading frame of OnRBL-L is 678 bp encoding 225 aa. The sequence of OnRBL-L has relatively conservative characteristic peptide motifs, including YGR, DPC, and KYL-motif. Expression analysis showed that OnRBL-L was abundantly distributed in intestine tissue, and widely existed in all detected tissues. Meanwhile, the expression of OnRBL-L increased significantly in vivo (liver, spleen, head kidney, intestine, gills and peripheral blood) and in vitro (monocytes/macrophages) following challenges with two important tilapia pathogenic bacteria Streptococcus agalactiae and Aeromonas hydrophila . In addition, the recombinant OnRBL-L was found to bind and agglutinate S. agalactiae and A. hydrophila . Furthermore, OnRBL-L could participate in non-specific cellular immune defense, including reducing the expression of pro-inflammatory factors ( IL-6 、 IL-8 and TNF-α ), and enhancement of the phagocytosis and respiratory burst of MO/MФ. Overall, our results provide new insights into the understanding of RBL as an important pattern recognition molecule and regulator in non-specific cell immunity in an early vertebrate. Highlights: · The RBL-like gene was identified in Nile tilapia ( OnRBL-L ). · OnRBL-L expression was significantly up-regulated following challenges with bacteria. · Recombinant OnRBL-L possessed binding and agglutination bacteria ability. · Recombinant OnRBL-L could participate in the regulation of inflammation, phagocytosis and respiratory burst.