A novel hepatic lectin of zebrafish Danio rerio is involved in innate immune defense. Issue 98 (March 2020)

• Record Type: Journal Article
• Authors: Yang, Qingyun; Wang, Peng; Yang, Shuaiqi; Li, Xianpeng; Zhang, Xiangmin; Ji, Guangdong; Zhang, Shicui; Wang, Su; Li, Hongyan
• Is Part Of: Fish & shellfish immunology. Issue 98(2020)
• Page Start: 670
• Page End: 680
• Publication Date: 2020-03
• Subjects: Zebrafish -- Danio rerio -- C-type lectin -- Hepatic lectin -- Innate immunity; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2019.10.068
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: ASGPR (asialoglycoprotein receptor, also known as hepatic lectin) was the first identified animal lectin, which participated in a variety of physiological processes. Yet its detailed immune functions are not well studied in lower vertebrates. After reporting a zebrafish hepatic lectin (Zhl), we identified a novel hepatic lectin (zebrafish hepatic lectin-like, Zhl-l) in zebrafish. The zhl-l was mainly expressed in liver in a tissue specific manner. And challenge with LPS/LTA induced a significant change of zhl-l expression. What's more, recombinant C-type lectin domain (rCTLD) of Zhl-l had the activity of agglutinating and binding to both Gram-negative and Gram-positive bacteria. It promoted the phagocytosis of bacteria by carp macrophages. Moreover, rCTLD could bind to insoluble lipopolysaccharide (LPS), lipoteichoic acid (LTA) and peptidoglycan (PGN) independent of Ca 2+, which was inhibited by galactose. Interestingly, Zhl-l was located in the membrane, and its overexpression could upregulate the production of pre-inflammatory cytokines. Taken together, these results indicated that Zhl-l played a role in immune defense, and would provide further information to understand functions of C-type lectin family and the innate immunity in vertebrates. Highlights: A novel zebrafish hepatic lectin (Zhl-l) was identified, whose expression was up-regulated upon LPS/LTA challenge. Zhl-l agglutinated both Gram-negative and Gram-positive bacteria in Ca 2+ -dependent manner, and bound to them in Ca 2+ -independent manner. Zhl-l bound to bacteria via interaction with LTA, LPS and PGN, which could be inhibited by galactose. Zhl-l could act as opsonin to enhance the phagocytosis of bacteria by macrophages. Overexpression of zhl-l could up-regulate the production of pre-inflammatory cytokines.