Objective:To purify Mannan-binding lectin(MBL)from human serum and detect its binding ability to several kindsof bacteria common in infections diseases of children.Methods:MBL was purifide from human serum by affinity...Objective:To purify Mannan-binding lectin(MBL)from human serum and detect its binding ability to several kindsof bacteria common in infections diseases of children.Methods:MBL was purifide from human serum by affinity chromatographyon mannan-Sepharose 4B column.Its binding ability to eight species,97 stratus of bacteria was detected by enzyme-linked lectinassay(ELLA).Results:MBL has different binding ability to bacteria and shows strong binding ability to Klebsiella ornithinolvticaand Escherichia coli,but shows relatively lower binding ability to Staphylococcus haemolyticus,Enterobacter cloacae andStaphylococcus epidermidis.To different isolates of Klebsiella pneumoniae,Haemophilus influenzae and Staphylococcus aureus,MBL shows quite different binding ability.Conclusions:MBL has different binding ability to different bacteria,and has relativelystronger binding ability to Gram-negative bacteria.Its binding ability to different isolates of certain kinds of bacteria is quitedifferent.展开更多
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
The production of free radicals is a natural process in aerobic organisms due to the mitochondrial activity. Usually the cells have several mechanisms for scavenging those free radicals, but, in several pathologic pro...The production of free radicals is a natural process in aerobic organisms due to the mitochondrial activity. Usually the cells have several mechanisms for scavenging those free radicals, but, in several pathologic processes, such as cancer, those free radicals increase their production, making it impossible to sustain the system stable, generating the condition called oxidative stress. Ruta graveolens L. （Rue） is a plant commonly used in traditional medicine, mainly as antiinflamatory; this has been related to some organic components, such as Rutin, but there hasn＇t been any lectin studies in Rue stem. Lectins are glycoproteins of non-enzymatic and no immune origin, able to bind to simple carbohydrates, which lets them bind selectively to malignant cells against normal cells, killing them via apoptosis and reducing the free radicals level. In this study we intended to characterize rue stem lectins as those weren＇t reported yet. Also, the anticancer and antioxidant activity of these lectins was evaluated, Rue stem lectins were extracted using a saline solution and semipurified to obtain an enriched extract and administrated to nickel oxide treated mice. Oxidative stress was cuantified using the tiobarbituric acid （TBARS） method to quantify Malondialdehyde （MDA）, the Griess method to cuantify Nitrites and enzymatic activity of catalase were cuantified in liver. In this study was found that rue stem lectins are useful as a therapeutic auxiliar, considering that its ratio of antioxidant activity is limited, being a prooxidant agent at high concentrations.展开更多
文摘Objective:To purify Mannan-binding lectin(MBL)from human serum and detect its binding ability to several kindsof bacteria common in infections diseases of children.Methods:MBL was purifide from human serum by affinity chromatographyon mannan-Sepharose 4B column.Its binding ability to eight species,97 stratus of bacteria was detected by enzyme-linked lectinassay(ELLA).Results:MBL has different binding ability to bacteria and shows strong binding ability to Klebsiella ornithinolvticaand Escherichia coli,but shows relatively lower binding ability to Staphylococcus haemolyticus,Enterobacter cloacae andStaphylococcus epidermidis.To different isolates of Klebsiella pneumoniae,Haemophilus influenzae and Staphylococcus aureus,MBL shows quite different binding ability.Conclusions:MBL has different binding ability to different bacteria,and has relativelystronger binding ability to Gram-negative bacteria.Its binding ability to different isolates of certain kinds of bacteria is quitedifferent.
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.
文摘The production of free radicals is a natural process in aerobic organisms due to the mitochondrial activity. Usually the cells have several mechanisms for scavenging those free radicals, but, in several pathologic processes, such as cancer, those free radicals increase their production, making it impossible to sustain the system stable, generating the condition called oxidative stress. Ruta graveolens L. （Rue） is a plant commonly used in traditional medicine, mainly as antiinflamatory; this has been related to some organic components, such as Rutin, but there hasn＇t been any lectin studies in Rue stem. Lectins are glycoproteins of non-enzymatic and no immune origin, able to bind to simple carbohydrates, which lets them bind selectively to malignant cells against normal cells, killing them via apoptosis and reducing the free radicals level. In this study we intended to characterize rue stem lectins as those weren＇t reported yet. Also, the anticancer and antioxidant activity of these lectins was evaluated, Rue stem lectins were extracted using a saline solution and semipurified to obtain an enriched extract and administrated to nickel oxide treated mice. Oxidative stress was cuantified using the tiobarbituric acid （TBARS） method to quantify Malondialdehyde （MDA）, the Griess method to cuantify Nitrites and enzymatic activity of catalase were cuantified in liver. In this study was found that rue stem lectins are useful as a therapeutic auxiliar, considering that its ratio of antioxidant activity is limited, being a prooxidant agent at high concentrations.
