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Updated: Jan 5, 2026

Functional Characterization of Regulatory Macrophages That Inhibit Graft-reactive Immunity
Published on: June 7, 2017
Functional characterization of galectin-3 from Nile tilapia (Oreochromis niloticus) and its regulatory role on
Jinzhong Niu1, Yu Huang2, Xinchao Liu1
1College of Fishery, Guangdong Ocean University, Zhanjiang, 524088, China; Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, China; Guangdong Key Laboratory of Control for Diseases of Aquatic Economic Animals, Zhanjiang, China.
Abstract:
Galectin-3 is a kind of β-galactoside-binding lectin involved in host defense against pathogen infection. However, the immune functions of fish galectin-3 remain poorly understood. In this study, the roles of a fish galectin-3 (OnGal-3) from Nile tilapia (Oreochromis niloticus) on the binding activity on bacterial pathogens or PAMPs, the agglutinating activity on bacterial pathogens and the regulatory effects on monocytes/macrophages activity were investigated. After in vitro challenge of Streptococcus agalactiae and Aeromonas hydrophila, OnGal-3 expressions were significantly up-regulated in monocytes/macrophages. In addition, recombinant OnGal-3(rOnGal-3) protein showed strong binding activity on bacterial pathogens or PAMPs. Also, rOnGal-3 agglutinated Gram-positive and Gram-negative bacteria. Moreover, rOnGal-3 could induce the inflammatory factors expressions in monocytes/macrophages and enhance phagocytosis and respiratory burst activity of monocytes/macrophages. These results suggest that fish galectin-3 participates in anti-bacterial immune response through recognizing pathogens and modulating monocytes/macrophages activity.

