1. Immune recognition, antimicrobial and opsonic activities mediated by a sialic acid binding lectin from Ruditapes philippinarum.
- Author
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Li, Shengqiang, Ruan, Zeli, Yang, Xiyun, Li, Mingzhu, and Yang, Dinglong
- Subjects
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MANILA clam , *IMMUNE recognition , *SIALIC acids , *PATTERN perception receptors , *LECTINS , *VIBRIO anguillarum , *BETA-glucans , *GLUCANS - Abstract
In the present study, a sialic acid-binding lectin was identified and characterized from Manila clam Ruditapes philippinarum (designed as RpSABL-1). Multiple alignments strongly suggested that RpSABL-1 was a new member of the sialic acid-binding lectin family. In non-stimulated clams, RpSABL-1 transcripts were constitutively expressed in all five tested tissues, especially in hepatopancreas. After Vibrio anguillarum challenge, the expression of RpSABL-1 mRNA was significantly up-regulated at 6 h (P < 0.05), 12 h (P < 0.01) and 24 h (P < 0.01). Recombinant RpSABL-1 protein (rRpSABL-1) displayed apparent binding activities towards lipopolysaccharides (LPS) and peptidoglycan (PGN), but not to glucan or chitin in vitro. Coinciding with the PAMPs binding assay, rRpSABL-1 exhibited obvious agglutination activities against Gram-positive bacterium Staphyloccocus aureus , Gram-negative bacteria Escherichia coli, V. anguillarum and Vibrio harveyi. Meanwhile, rRpSABL-1 showed antibacterial activities against E. coli , and biofilm formation of E. coli could also be inhibited after incubated with rRpSABL-1. Moreover, the encapsulation, phagocytosis and chemotactic ability of hemocytes could be enhanced by rRpSABL-1. All these results suggested that RpSABL-1 could function as a pattern recognition receptor with versatile functions in the innate immune responses of R. philippinarum. • A sialic acid binding lectin (SABL) was identified from the manila clam Ruditapes philippinarum. • Recombinant RpSABL-1 showed a broad agglutination spectrum against Gram-positive and Gram-negative bacteria. • RpSABL-1 could function as a pattern recognition receptor with broad recognition spectrum. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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