Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Qingdao, 266003, China; Department of Marine Biology, Ocean University of China, Qingdao, 266003, China.
Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Qingdao, 266003, China; Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, 266109, China.
Fish Shellfish Immunol. 2020 Mar;98:670-680. doi: 10.1016/j.fsi.2019.10.068. Epub 2019 Nov 2.
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, 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.
ASGPR（即唾液酸糖蛋白受体，也称为肝凝集素）是第一个被鉴定的动物凝集素，参与多种生理过程。然而，其在低等脊椎动物中的详细免疫功能尚未得到充分研究。在报道了一种斑马鱼肝脏凝集素（Zhl）之后，我们在斑马鱼中鉴定了一种新型的肝脏凝集素（斑马鱼肝脏凝集素样，Zhl-l）。Zhl-l 主要以组织特异性方式在肝脏中表达。而且，LPS/LTA 刺激会引起 zhl-l 表达的显著变化。更重要的是，Zhl-l 的重组 C 型凝集素结构域（rCTLD）具有凝集和结合革兰氏阴性和革兰氏阳性细菌的活性。它促进了鲤鱼巨噬细胞对细菌的吞噬作用。此外，rCTLD 可以结合不溶性脂多糖（LPS）、脂磷壁酸（LTA）和肽聚糖（PGN），无需 Ca 参与，而半乳糖可以抑制其结合。有趣的是，Zhl-l 位于膜上，其过表达可以上调促炎细胞因子的产生。总之，这些结果表明 Zhl-l 在免疫防御中发挥作用，并将为进一步了解脊椎动物 C 型凝集素家族和先天免疫的功能提供信息。
