Acting as one of the pattern recognition receptors （PRRs）, C-type lectin is believed to mediate pathogen recognition and plays an important role in the clearance of pathogens as part of the innate immune system. In ...Acting as one of the pattern recognition receptors （PRRs）, C-type lectin is believed to mediate pathogen recognition and plays an important role in the clearance of pathogens as part of the innate immune system. In this work, a novel C-type lectin gene （named LvLecl） was cloned from the shrimp Litopenaeus vannamei, The ORF of LvLecl is 510 bp, encoding 169 amino acids. The deduced amino acid sequence contains a putative signal peptide of 19 amino acids at the N-terminal and a carbohydrate recognition domain （CRD） at the C-terminal. LvLecl was mainly expressed in the hepatopancreas. Real-time PCR analysis indicated that the level of LvLecl transcripts significantly changed in the hepatopancreas after the shrimp were artificially challenged with LPS, Micrococcus lysodeikticus and white spot syndrome virus （WSSV）. RNAi-based silencing of LvLecl resulted in increases in mortality when the shrimp were challenged with WSSV, and the median lethal time was reduced compared with controls. Although there was no characteristic ＂EPN＂ （Glu-Pro-Ser） or ＂QPD＂ （Gin-Pro-Asp） motif, the recombinant LvLecl, expressed in Escherichia coli BL21 （DE3）, could also agglutinate M. lysodeikticus and Vibrio anguillarum. The agglutinating activities were calcium-dependent and could be inhibited by D-mannose, D-glucose, D-galactose and N-Acetyl-D-mannose. These results suggest that LvLecl might be involved in the immune response against WSSV and bacterial infections and contribute to non-self recognition as a pattern recognition receptor in the innate immune system of the shrimp L. vannamei.展开更多
基金Supported by the National Basic Research Program of China (973 Program) (No. 2006CB101804)the National Natural Science Foundation of China (No. 30972245)Public Industry (Agriculture) Specific Research Program (No. 200803012)
文摘Acting as one of the pattern recognition receptors （PRRs）, C-type lectin is believed to mediate pathogen recognition and plays an important role in the clearance of pathogens as part of the innate immune system. In this work, a novel C-type lectin gene （named LvLecl） was cloned from the shrimp Litopenaeus vannamei, The ORF of LvLecl is 510 bp, encoding 169 amino acids. The deduced amino acid sequence contains a putative signal peptide of 19 amino acids at the N-terminal and a carbohydrate recognition domain （CRD） at the C-terminal. LvLecl was mainly expressed in the hepatopancreas. Real-time PCR analysis indicated that the level of LvLecl transcripts significantly changed in the hepatopancreas after the shrimp were artificially challenged with LPS, Micrococcus lysodeikticus and white spot syndrome virus （WSSV）. RNAi-based silencing of LvLecl resulted in increases in mortality when the shrimp were challenged with WSSV, and the median lethal time was reduced compared with controls. Although there was no characteristic ＂EPN＂ （Glu-Pro-Ser） or ＂QPD＂ （Gin-Pro-Asp） motif, the recombinant LvLecl, expressed in Escherichia coli BL21 （DE3）, could also agglutinate M. lysodeikticus and Vibrio anguillarum. The agglutinating activities were calcium-dependent and could be inhibited by D-mannose, D-glucose, D-galactose and N-Acetyl-D-mannose. These results suggest that LvLecl might be involved in the immune response against WSSV and bacterial infections and contribute to non-self recognition as a pattern recognition receptor in the innate immune system of the shrimp L. vannamei.
