Mannose-binding lectin and maladies of the bowel and liver

Mannose-binding lectin (MBL) is a pattern-recognition molecule that binds to characteristic carbohydrate mo-tifs present on the surface of many different pathogens. MBL binding stimulates the immune system via the lectin pathway of complement activation. In certain clinical situations, often characterized by pre-existing immune compromise, MBL deficiency increases the risk of infec-tious and other disease-specific complications. Many of the key pathogenic processes inherent to common gastroenterological diseases, such as infection, immuno-logical damage, and carcinogenesis, have been linked to MBL. This editorial reviews the biology of MBL, outlines key disease associations to document the breadth of influence of MBL, and finally, highlights the relevance of MBL to both gastroenterological health and disease.

Mannose-binding Lectin Two Gene Polymorphisms and Tuberculosis Susceptibility in Chinese Population: A Meta-analysis

Numerous studies have been done to explore the association between mannose-binding lectin two （MBL2） gene polymorphisms and the risk of tuberculosis （TB）. However, the results are inconsistent. We performed a meta-aualysis to investigate whether polymorphisms in the MBL2 gene were associated with TB risk. Databases including PubMed, Medline, Chinese Biomedicine Database, China National Knowledge Infrastructure, Wanfang Database, and Weipu Database were searched to find relevant articles published up to 2 October, 2012. Odds ratio （OR） with 95% confidence interval （CI） was used to evaluate the strength of association. All statistical tests were performed by using Revman 5.1 software and STATA 11.0 software. Six case-control studies including 1106 cases and 1190 controls were accepted in the meta-analysis. The results indicated that individuals carrying the MBL2 codon 54 B allele may have an increased risk of TB as compared with AA homozygotes （BB＋AB vs. AA： OR=1.52, 95% CI： 1.22-1.88）, whereas MBL2 ＋4 P/Q was possibly not associated with TB susceptibility in Chinese population.

Mannose-binding lectin 2 rs11003123 polymorphism is associated with the development of hepatocellular carcinoma in patients with hepatitis B-related cirrhosis in the Chinese population

BACKGROUND： Mannose-binding lectin 2 （MBL2） plays a key role in the host immune response, but whether it is associ- ated with hepatocellular carcinoma （HCC） is not dear. The present study aimed to identify the association between MBL2 gene polymorphisms and HCC in patients with hepatitis B virus （I-IBV）-related cirrhosis in the Chinese population.

Early expression of mannose-binding lectin 2 during Aspergillus fumigatus infection in human corneal epithelial cells

AIM: To evaluate the early expression of mannose-binding lectin 2(MBL2) in human corneal epithelial cells(HCECs) infected by Aspergillus fumigatus(AF).METHODS: HCECs cultured in vitro with AF antigens and sampled at 0, 0.5, 1, 2, 4, 6 and 8h. The expression of MBL2 m RNA was evaluated by semiquantitative reverse transcription-polymerase chain reaction(RT-PCR). The expression of MBL2 protein in supernatant fluid was shown by enzyme linked immunosorbent assay(ELISA). MBL2 protein in HCECs was detected by immunocytochemistry at 0 and 24 h.RESULTS: MBL2 m RNA and protein are expressed in normal HCECs. The expression of MBL2 m RNA and protein in supernatant fluid begin to increase after being stimulated with AF antigens. The most significantly peak of MBL2 m RNA is in 2h. The protein of MBL2 in supernatant fluid decrease gradually after 0.5h. The protein in HCECs expression increase after stimulation of24 h.· CONCLUSION: MBL2 receptor expressed in normal HCECs in vitro. The stimulation by AF antigens can increase the early expression of it.

Expressions and clinical significances of mannose-binding lectin(MBL) and MBL-associated serine protease 2(MASP-2) in patients with thyroid neoplasm

Objective： The aim of the study was to detect the levels of mannose-binding lectin （MBL）, MBL-associated serine protease 2 （MASP-2） and explore the clinical significances of them in patients with primary thyroid neoplasms. Methods： By using ELISA method, we detected the serum levels of MBL and MASP-2 in 26 patients with papillary thyroid carcinoma （PTC）, 30 patients with thyroid adenoma （TA） and 26 healthy people, respectively. Results： Serum MBL level was （565.23 ± 76.70） μg/L in PTCs higher than （324.267 ±24.74） μg/L in TAs, and （152.69± 16.95） IJg/L in healthy of controlling group. There was statistical significance between PTC and TA （P 〈 0.05）, however there was no difference between TA and healthy （P 〉 0.05）. Serum MASP-2 level was （726.153± 78.88） pg/L in PTCs higher than （379.266 ± 30.26） μg/L in TAs, and （203.846 ± 29.09） μg/L in healthy. Serum MASP-2 level was higher in PTCs than TAs, and the difference had statistical significance （P 〈 0.01）. But no difference was observed between in TAs and healthy. Conclusion： These findings might reflect inflammatory processes induced by defense mechanisms, in response to the development of the turnout. MBL may also be involved in the elimination of possible tumourigenic pathogens.

Dietary sugars inhibit biologic functions of the pattern recognition molecule, mannose-binding lectin

Mannose-binding lectin (MBL), a mammalian lectin, is a pattern recognition molecule of the innate immune system and recognizes carbo-hydrates that are exposed on pathogens. In this study, we observed that fructose down regu-lates MBL-mediated innate immune mechanisms against both influenza A virus (IAV) and Staphy-lococcus aureus. These mechanisms include the lectin complement pathway and coagulation enzyme-like activities on both pathogens. Fur-thermore, fructose also reduces MBL-mediated phagocytosis of S. aureus and IAV and MBL- mediated IAV infection to epithelial cells. In contrast, sucrose inhibits MBL-mediated im-mune mechanisms against S. aureus but not IAV. Together, our studies show that dietary sugars, in particular fructose, negatively regulate the innate immunity against viral and bacterial pathogens.

Evolutionary analysis of plant jacalin-related lectins(JRLs)family and expression of rice JRLs in response toMagnaporthe oryzae

Jacalin-related lectins （JRLs） are widely distributed carbohydrate-binding proteins in the plant kingdom, which play key roles in development and pathogen defense. In this study, we profiled evolutionary trajectory of JRLs family in 30 plant species and identified domain diversification and recombination leading to different responsive patterns of JRLs in rice during defense against rice blast. All of 30 plant species analyzed in our study have two types of JRLs by containing either a single jacalin or repeated jacalin domains, while chimeric jacalins exist in more than half of the species, especially in the Poaceae family. Moreover, Poaceae species have evolved two types of unique chimeric JRLs by fusing the jacalin domain（s） with dirigent or NB_ARC domain, some of which positively regulate plant immunity. Seven Poaceae-specific JRLs are found in the rice genome. We further found expression of rice JRLs, including four Poaceae-specific JRLs, are induced by Magnaporthe oryzae infections at either early or late infection stages. Overall, the results present the evolutionary trajectory of JRLs in plant and highlight essential roles of Poaceae specific JRLs against pathogen attacks in rice.

Agglutination of Helicobacter pylori coccoids by lectins

AIM To study the agglutination pattern ofHelicobacter pylori coccoid and spiral forms.METHODS Assays of agglutination andagglutination inhibition were applied usingfifteen commercial lectins.RESULTS Strong agglutination was observedwith mannose-specific Concanavalin A(Con A),fucose-specific Tetragonolobus purpureas(Lotus A)and N-acetyl glucosamine-specificTriticum vulgaris(WGA)lectins.Mannose andfucose specific lectins were reactive with allstrains of H.pylori coccoids as compared to thespirals.Specific carbohydrates,glycoproteinsand mucin were shown to inhibit H.pylorilectin-agglutination reactions.Pre-treatment ofthe bacterial cells with formalin and sulphuricacid did not alter the agglutination patterns withlectins.However,sodium periodate treatment ofbacterial cells were shown to inhibitagglutination reaction with Con A,Lotus A andWGA lectins.On the contrary,enzymatictreatment of coccoids and spirals did not showmarked inhibition of H.pylori-lectinagglutination.Interestingly,heating of H.pylori cells at 60℃ for 1 hour was shown toaugment the agglutination with all of the lectinstested.CONCLUSION The considerable differences inlectin agglutination patterns seen among the twodifferentiated forms of H.pylori might beattributable to the structural changes during theevents of morphological transformation,resulting in exposing or masking some of the sugar residues on the cell surface.Possibility ofvarious sugar residues on the cell wall of thecoccoids may allow them to bind to differentcarbohydrate receptors on gastric mucus andepithelial cells.The coccoids with adherencecharacteristics like the spirals could aid in thepathogenic process of Helicobacter infection.This may probably lead to different clinicaloutcome of H.pylori associated gastroduodenaldisease.

Detection of Lectins by Saccharide-gold Nanoparticle Conjugates

A general functionalization strategy was reported,which enables one to conjugate saccharide（SA） on gold nanoparticle（GNP） surface without affecting SA properties.First,disulfide phenylboronic acid（Bor） functionalized GNPs（Bor@GNPs） were synthesized by the reaction of citrate stabilized GNPs of 13 nm in diameter with the mixture of Bor and pentapeptide（Cys-Ala-Leu-Asn-Asn,CALNN）.Subsequently,the SA-GNP conjugates（SA@GNPs） were prepared by coupling SA to the GNP surface via the reaction of phenylboronic acid（PBA） with the cis-diol configuration in SA.The interactions of three SA@GNPs with three lectins have been analyzed by UV-visible spectroscopic and transmission electronic microscopic（TEM） techniques,respectively.The experimental results demonstrate that SA@GNPs can efficiently bind to lectins and show a great promise as optical probes for monitoring specific affinities of lectins for SA,and detecting lectins with high sensitivity.

Influence of maternal experimental hypothyroidism on quantitative-qualitative indicator of rat progeny skin mast cells in age aspect according to histochemical investigation results and on the base of lectins GNA and PNA receptors cytotopography

Amount of thyroid pathology patients in Ukraine increased 3.7 times from 0.9 to 3.5 per 1000 population within a decade. The main reason of most of organs damage associated with hypothyroidism is decreased synthesis of number of cellular enzymes because of thyroid hormones deficiency. Mast cells (MC) play leading role in inflammatory processes, allergic reactions and in autoimmune diseases pathogenesis, since they produce various cytokines. Influence of maternal hypothyroidism on the progeny skin histogenesis and MC correlation is poorly studied. Hypothyroid condition was modeled in Wistar female rats by adding thyreostatic drug mercazolilum (methimazole) 5 mg/kg body mass. Thyroid glands and progeny skin pieces from the back on the 1, 10, 20 and 40 postnatal development days were fixed in 4% neutral formalin and embedded in paraffin. For MC detection slides were stained by Bismark brown, alcian blue (pH 2.5), toluidine blue. D-Man and β-DGal carbohydrate determinants were studied by use of GNA and PNA lectins labeled with horseradish peroxidase. Lectin receptors visualization was conducted in3’3-diaminobenzidine tetrahydrochloride system in Н2О2 presence. Counting the MC number and thyroid glands’ morphometric parameters were conducted on 5 μm thin sections by using UTHSCSA “Image Tool for Windows Version2.00”(USA) computer program. Statistical analysis was performed using Student t-test. Body mass increase, changes in thyroid cells parameters and colloid structure were stated in experimental animals. The biggest MC amount was detected in control animals skin on the 1 day of postnatal development, slight decrease on 10 day and gradual increase till 40 day. MC amount with signs of degranulation increased in experimental animals skin at all stages of the research. Simultaneously, D-Man and β-DGal glycopolymers expression similarity was noted on MC surface. According to MC quantitative-qualitative indicators in skin, hypothyroid female rat progeny should be included into the risk group of immune status change and allergic reactions beginning.

Drug Delivery: Plant Lectins as Bioadhesive Drug Delivery Systems

Selective targeting of drugs to the proposed site of action provides therapeutic advantages such as reduced toxicity and smaller dose levels. Despite a huge progress made in drug design and delivery systems, many challenges still have to be solved. Small therapeutic drugs always have the potential to pass into the kidneys and be excreted from the body. The use of macromolecular constructs (carriers) that allow longer circulation times, contribute to improved chemical functionality and more precise drug delivery is an attractive alternative option. Bioadhesive systems which will utilize intense contact to increase the drug concentration gradient could be an attractive approach. Because of their specific carbohydrate-binding, lectins can interact with glycoconjugates present on the epithelial cells that line all of the organs exposed to the external environment. The unique carbohydrate specificities of plant lectins can facilitate mucoadhesion and cytoadhesion of drugs. As immunostimulatory molecules with an adjuvant effect plant lectins can also be employed in vaccine development.

Extraction of Six Seaweed Lectins and Comparison of Their Lectin Activity

Seaweeds are marine biological resources rich in a variety of bioactive substances with a wide range of biological functions.In this research,lectins were extracted from C.ocellatus Holmes,Rhodomela C.Ag,Laminaria japonica Aresch,Undaria pinnati fida,Porphyra yezoensis Ueda and Alga Scytosiphonis Lomentarii.The activities of the lectins were measured and analyzed respectively.The results showed that the effect of extracting the lectin with normal saline was better,and the activity in kelp crude extract was better.It can provide a reference for further development and utilization of economic seaweed.

Characterization and comparison of two C-type lectins with novel key motifs from mud crab Scylla paramamosain

As an important pattern recognition receptor(PRR)in the innate immune system,C-type lectin plays an important role in the innate immune process of invertebrates.Two C-type lectins Sp CTL-C and Sp CTL-D were characterized from mud crab(Scylla paramamosain).The predicted Sp CTL-C and Sp CTL-D proteins both contain a single carbohydrate-recognition domain(CRD)with key motif Gln-Pro-Ala(QPA)and Met-Pro-Ala(MPA),respectively.Sp CTL-C and Sp CTL-D transcripts distributed in all examined tissues,and the expression level was the highest in hepatopancreas.As PRR,the purifi ed recombinant proteins r Sp CTL-C and r Sp CTL-D have high affi nity for three kinds of pathogen-associated molecular patterns(PAMPs):β-glucan,lipopolysaccharide,and peptidoglycan.Besides,r Sp CTL-D can bind to all nine microorganisms tested,while r Sp CTL-C can bind to seven microorganisms except for Staphylococcus aureus and Micrococcus luteus.Both r Sp CTL-C and r Sp CTL-D showed agglutination activity towards fungi Pichia pastoris and Saccharomyces cerevisiae.However,r Sp CTL-C and r Sp CTL-D exhibited diff erent antimicrobial activities:r Sp CTL-D has a certain inhibitory eff ect on the growth of Vibrio fl uvialis and M.luteus,while r Sp CTL-C has no obvious inhibitory activity.The results show that r Sp CTL-C and r Sp CTL-D had better phagocytosis-promoting eff ect on M.luteus than the negative control.Meanwhile,both r Sp CTL-C and r Sp CTL-D had certain encapsulation-promoting activity.Collectively,two C-type lectins with novel key motifs make an important impact as PRR in immune response towards pathogens.At the same time,they play diff erent functions in the innate immunity of mud crab S.paramamosain.

Screening of Lectins in Crab and Shrimp from Fujian Coast of China

Twelve species of crustacean from Fujian coast were examined for lectins with different animal erythrocytes. Serum extracts froma ll of 12 species showed agglutinating activity against at least two types of the erythrocytes used, which revealed the existence of lectins in these species. There were five species ( Penaeus japonicus , Lophosquilla costata, Charybdis feriatus, Portunus pelagicus, Scylla serrata ) whose serums could agglutinate all the erythrocytes tested. The lowest serum protein concentration required to produce erythrocytes agglutination varied remarkably, ranging from 0.7μ g/mL to 8 080μ g/mL. The strongest activity was shown in the agglutination of rabbit erythrocyte by serum of Penaeus vanaminas. Inhibition assays performed with seven mono- and bisaccharides showed that agglutination of quail erythrocytes by serums of three species (Portunus pelagicus, Scylla serrata and Sesarma sp. ) were not inhibited by any sugars, while others were inhibited by at least three types of sugars. The assay of temperature influence on agglutinating activity showed that only Penaeus japonicus retained activity when the serum was heated to 90 ℃, and other serums lost their activity at 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃ for 10 minutes, respectively.

New Extracellular Bacillus subtilis Lectins with Sialic Acid-Specificity

The purpose of this work is to perform a detailed study of carbohydrate specificity of the new extracellular bacilli lectins which is considered to determine mechanisms of the lectins action. Sources of lectins were bacterial strains from Ukrainian collection of microorganisms. The optimized protocol of bacilli lectins isolation and purification included precipitation with ammonium sulfate with subsequent gel filtration chromatography on Sepharose CL-6B. Hemagglutinating activity of bacilli lectins and their fine carbohydrate specificity to sialic acids and their derivatives as well as sialic asid-containing and asialic glycoconjugates were studied. The ability of extracellular bacilli lectins to discriminate a- and 13-conformation of carbohydrate molecule and the type of connection between the monomers was determined. Studied lectins showed the most affinity to glycoconjugates containing both types of sialic acids （N-acetylneuraminic acid （Neu5Ac） and N-glycolylneuraminic acid （NeuGc）） and it is supposed to be a basis of their diagnostic and analytical potential.

A STUDY OF LECTINS IN HUMAN BREAST CANCER AND PRECANCEROUS LESIONS

This paper report the binding pattern of 12 different kinds of lectin in human breast lesions. Of the 12 kinds of lectins, WGA showed the highest binding activity to the cells of the breast tissue derived; the binding of BSL, SBA and DBA were localized to membrane or cytoplasm of cancer cells and to the lumina membrane border of the normal and benign lesions; PNA receptor is related with the differentiation of the breast; cancer; we didn't find any relationship between the lectin receptor and the tendency of metastasis of breast cancer.

Oxidative Stress Evaluation in Cancer-Induced Mice Treated with Ruta graveolens L. Stem lectins

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.

Effect of a Thermal Spring Water on Carbohydrate-Protein Interactions in In-Vitro Models Implicating Normal Human Keratinocytes and Recombinant Lectins

Background: Sugar moiety of macromolecules is today very well known for its implications in many biological recognition mechanisms including cell-cell, extracellular matrix-cell and/or bacteria-cell interactions. In this context lectins, which are carbohydrate-binding proteins displaying a high affinity for sugar groups of other molecules, are of a great importance, notably in immune response involving bacteria, viruses and fungi. As protein-carbohydrate interactions are often mediated by ions such as calcium, zinc or magnesium, we were prompted to study the effect of a thermal spring water (which contains this type of component) on interactions existing between: 1) osidic receptors of human normal keratinocytes and 2) two lectins greatly implicated in the immune response mechanisms (i.e. the dectin-1 and the langerin), and their ligands. Materials and Methods: In a first series of experiments, we studied the effect of increasing concentrations of a thermal spring water on interactions existing between glycosylated molecules and the osidic receptors expressed at the normal human keratinocytes surface. In a second step, and in order to better understand the putative effect of our thermal spring water on the immune response, we analyzed its effect on the interactions existing between the dectin-1 (implicated in the recognition of bacteria, viruses and fungi) and the langerin (expressed by Langerhans cells, the immune cells of the cutaneous tissue), and their ligands in a model using recombinant human lectins and appropriate binding molecules. Results: We showed here that our thermal spring water was able to reinforce interactions between keratinocytes osidic receptors and some of their ligands, in a dose-related manner: From 8% to 55% of increase with 10% to 30% (v/v) of thermal spring water. In the second part of our studies, we also showed that our thermal spring water was able to modulate interactions between dectin-1 and langerin and their ligands through a biphasic effect: Interactions were enhanced by more than 40% and 20% respectively with 10% of thermal spring water, and return to their basal level or lower for higher concentrations. Conclusion: The tested thermal spring water, probably due to its ionic composition, could significantly affect interactions of osidic receptors with their ligands. This property could be of a great interest to help immune system to maintain an appropriate “vigilance state” by using the thermal water at up to a concentration of 10%, and by avoiding any runaway reaction in case of aggression, by using concentrations higher than 10%. .

Establishment of a Multiplex Detection Method for Common Bacteria in Blood Based on Human Mannan-Binding Lectin Protein-Conjugated Magnetic Bead Enrichment Combined with Recombinase-Aided PCR Technology

Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannanbinding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP.Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays.Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05).Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.

C-type lectins and human epithelial membrane protein1:Are they new proteins in keratin disorders?

Here we report a family with a clinical spectrum of Pachyonychia Congenita Tarda (PCT) encompassing two generations via a balanced chromosomal translocation between 4q26 and 12p12.3. We discuss the effects of chromosomal translocations on gene expression through involved breakpoints and structural gene abnormalities detected by array CGH. We believe that the family we present gives further insight to the better understanding of molecular and structural basis of keratin disorders, and to the late onset and genetic basis of PCT through the possible role of C-type lectins and human epithelial membrane protein1 (EMP1). Better understanding of the molecular basis of keratin disorders is the foundation for improved diagnosis, genetic counseling and novel therapeutic approaches to overcome the current treatment limitations related to this disease.