文献类型：期刊文献

英文题名：An alpha-2 macroglobulin in the pearl oyster Pinctada fucata: Characterization and function in hemocyte phagocytosis of Vibrio alginolyticus

作者：Wang, Zhongliang[1,2];Wang, Bei[1,3];Chen, Gang[1,2];Lu, Yishan[1,3];Jian, Jichang[1,3];Wu, Zaohe[3]

机构：[1]Guangdong Ocean Univ, Coll Fisheries, Zhanjiang 524025, Peoples R China;[2]Guangdong Prov Key Lab Aquaculture South China Se, Zhanjiang 524025, Peoples R China;[3]Guangdong Prov Key Lab Pathogen Biol & Epidemiol, Zhanjiang 524025, Peoples R China

年份：2016

卷号：55

起止页码：585

外文期刊名：FISH & SHELLFISH IMMUNOLOGY

收录：SCI-EXPANDED(收录号：WOS:000381537000064)、、WOS

基金：This work was supported by grants from the National Natural Science Foundation of China (NSFC) (31202023), Science and Technology Planning Project of Guangdong Province, China (2015A020209169) and Project of Enhancing School with Innovation of Guangdong Ocean University (GDOU2015050214). We are especially grateful for the critical comments from the anonymous reviewers.

语种：英文

外文关键词：Alpha-2 macroglobulin; Phagocytosis; Pinctada fucata; RNAi; Innate immunity

外文摘要：Alpha-2 macroglobulin (alpha 2M) is a ubiquitous protease inhibitor and considered to be an evolutionarily conserved constituent of innate host defence system. Here, an a2M gene (designated as Pf alpha 2M) was obtained from the pearl oyster Pinctada fucata by RT-PCR, PCR walking and rapid amplification of cDNA ends (RACE). The Pf alpha 2M cDNA consists of 6394 bp with an open reading frame (ORF) of 5745 bp encoding a protein of 1914 amino acids with a 19 residues signal peptide. Pf alpha 2M sequence contains three putative functional domains, including a bait region, a thiol ester domain and a receptor-binding domain. Phylogenetic analysis revealed that Pf alpha 2M is closely related to the alpha 2Ms from other molluscs. Pf alpha 2M was expressed in all tested tissues including digestive gland, gill, adductor muscle, mantle and foot, while the highest expression was found in hemocytes. Following challenge with Vibrio alginolyticus, Pf alpha 2M expression in hemocytes was significantly up-regulated at 2 h and then returned to the original level at 48 h. Knockdown of Pf alpha 2M by RNA interference significantly reduced the phagocytosis of V. alginolyticus by hemocytes in vivo, and similar results were obtained upon chemical inactivation of the reactive thioester bond in Pf alpha 2M by methylamine treatment. Taken together, it is suggested that Pf alpha 2M is an immune-relevant molecule and involved in phagocytosis of V. alginolyticus by P. fucata hemocytes, and the function of Pf alpha 2M in phagocytosis is dependent on the active thioester bond. (C) 2016 Elsevier Ltd. All rights reserved.