a c1q domain containing protein from scallop chlamys farreri serving as pattern recognition receptor with heat-aggregated igg binding activityc1q域包含蛋白质扇贝斗篷farreri作为模式识别受体与heat-aggregated免疫球蛋白结合的活动.pdfVIP

A C1q Domain Containing Protein from Scallop Chlamys farreri Serving as Pattern Recognition Receptor with Heat-Aggregated IgG Binding Activity 1,2 1 1 1 1,2 1 Leilei Wang , Lingling Wang *, Huan Zhang , Zhi Zhou , Vinu S. Siva , Linsheng Song * 1 Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China, 2 Graduate University, Chinese Academy of Sciences, Beijing, China Abstract Background: The C1q domain containing (C1qDC) proteins refer to a family of all proteins that contain the globular C1q (gC1q) domain, and participate in a series of immune responses depending on their gC1q domains to bind a variety of self and non-self binding ligands. Methodology: In the present study, the mRNA expression patterns, localization, and activities of a C1qDC protein from scallop Chlamys farreri (CfC1qDC) were investigated to understand its possible functions in innate immunity. The relative expression levels of CfC1qDC mRNA in hemocytes were all significantly up-regulated after four typical PAMPs (LPS, PGN, b- glucan and polyI:C) stimulation. During the embryonic development of scallop, the mRNA transcripts of CfC1qDC were detected in all the stages, and the expression level was up-regulated from D-hinged larva and reached the highest at eye- spot larva. The endogenous CfC1qDC was dominantly located in the hepatopancreas, gill, kidney and gonad of adult scallop through immunofluorescence. The recombinant protein of CfC1qDC (rCfC1qDC) could not only bind various PAMPs, such as LPS, PGN, b-glucan as well as polyI:C, but also enhance the phagocytic activity of scallop hemocytes towards Escherichia coli. Meanwhile, rCfC1qDC could interact w