Identification of a novel C-type lectin from the shrimp Litopenaeus vannamei and its role in defense against pathogens infection  

作　　者：罗展 张继泉 李富花 张晓军 柳承璋 相建海 

机构地区：[1]Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences [2]Graduate University of Chinese Academy of Sciences

出　　处：《Chinese Journal of Oceanology and Limnology》2011年第5期942-951,共10页中国海洋湖沼学报（英文版）

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)

摘　　要：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.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 LvLec1) was cloned from the shrimp Litopenaeus vannamei. The ORF of LvLec1 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. LvLec1 was mainly expressed in the hepatopancreas. Real-time PCR analysis indicated that the level of LvLec1 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 LvLec1 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" (Gln-Pro-Asp) motif, the recombinant LvLec1, 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 LvLec1 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.

关 键 词：Litopenaeus vannamei innate immune pattern recognition receptor C-type lectin RNAinterference （RNAi） recombinant expression 

分 类 号：Q945[生物学—植物学]