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.

Mannose-binding lectin 2 gene polymorphisms and their association with tuberculosis in a Chinese population

Background:Immune-and inflammation-related genes(IIRGs)play an important role in the pathogenesis of tuberculosis(TB).However,the relationship between IIRG polymorphisms and TB risk remains unknown.In this study,the gene polymorphisms and their association with tuberculosis were determined in a Chinese population.Methods:We performed a case-control study involving 1016 patients with TB and 507 healthy controls of Han Chinese origin.Sixty-four single-nucleotide polymorphisms(SNPs)belonging to 18 IIRGs were genotyped by the PCR-MassArray assay,and the obtained data was analyzed withχ2-test,Bonferroni correction,and unconditional logistic regression analysis.Results:We observed significant differences in the allele frequency of LTA rs2229094*C(P=0.015),MBL2 rs2099902*C(P=0.001),MBL2 rs930507*G(P=0.004),MBL2 rs10824793*G(P=0.004),and IL12RB1 rs2305740*G(P=0.040)between the TB and healthy groups.Increased TB risk was identified in the rs930507 G/G genotype(Padjusted=0.027)under a codominant genetic model as well as in the rs2099902(C/T+C/C)vs T/T genotype(Padjusted=0.020),rs930507(C/G+G/G)vs C/C genotype(Padjusted=0.027),and rs10824793(G/A+G/G)vs A/A genotype(Padjusted=0.017)under a dominant genetic model after Bonferroni correction in the analysis of the overall TB group rather than the TB subgroups.Furthermore,the rs10824793_rs7916582*GT and rs10824793_rs7916582*GC haplotypes were significantly associated with increased TB risk(P=0.001,odds ratio[OR]=1.421,95%confidence interval[CI]:1.152-1.753;and P=0.018,OR=1.364,95%CI:1.055-1.765,respectively).Moreover,the rs10824793_rs7916582*AT/AT or rs10824793_rs7916582*GT/GT diplotype showed a protective(P=0.003,OR=0.530,95%CI:0.349-0.805)or harmful(P=0.009,OR=1.396,95%CI:1.087-1.793)effect against the development of TB.Conclusions:This study indicated that MBL2 polymorphisms,haplotypes,and diplotypes were associated with TB susceptibility in the Han Chinese population.Additionally,larger sample size studies are needed to further confirm these findings in the future.

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.

胸腔积液沉渣包埋组织TTF-1、Galectin-3的表达水平与肺腺癌恶性生物学行为间的关系

目的探讨胸腔积液沉渣包埋组织甲状腺转录因子1(TTF-1)、半乳糖凝集素-3(Galectin-3)的表达水平与肺腺癌恶性生物学行为间的关系。方法选取2020年10月至2023年3月在该院就诊的肺腺癌患者163例,根据分化程度分为高分化组(26例)、中分化组(78例)、低分化组(59例)。对比3组胸腔积液沉渣包埋组织TTF-1、Galectin-3及恶性生物学行为相关基因(p16基因mRNA)表达水平,Spearman秩相关系数分析胸腔积液沉渣包埋组织TTF-1、Galectin-3与p16基因mRNA表达水平的相关性,多元线性回归分析胸腔积液沉渣包埋组织TTF-1、Galectin-3与p16基因mRNA表达水平间的依存关系,限制性立方样条图分析胸腔积液沉渣包埋组织TTF-1、Galectin-3与p16基因mRNA表达水平间的剂量-效应关系。结果低分化组胸腔积液沉渣包埋组织TTF-1、Galectin-3表达水平高于中分化组、高分化组,p16基因mRNA表达水平低于中分化组、高分化组,中分化组胸腔积液沉渣包埋组织TTF-1、Galectin-3表达水平高于高分化组,p16基因mRNA表达水平低于高分化组,差异有统计学意义(P<0.05);胸腔积液沉渣包埋组织TTF-1(r=-0.752,P<0.001)、Galectin-3(r=-0.811,P<0.001)表达水平与p16基因mRNA表达水平呈负相关;胸腔积液沉渣包埋组织Galectin-3表达水平与p16基因mRNA表达水平间无线性依存关系(P>0.05),胸腔积液沉渣包埋组织TTF-1表达水平与p16基因mRNA表达水平间有线性依存关系(P=0.049);当胸腔积液沉渣包埋组织TTF-1表达水平<4分、胸腔积液沉渣包埋组织Galectin-3表达水平<3分时,对p16基因mRNA表达作用最显著。结论胸腔积液沉渣包埋组织TTF-1、Galectin-3表达水平与肺腺癌恶性生物学行为关系密切,早期检测对临床实现精准干预避免病情恶化具有重要意义。

LPS诱导小鼠脑小胶质细胞的激活及Tomato lectin的表达变化

探讨小胶质细胞对侧脑室注射内毒素脂多糖(lipopolysaccharide,LPS)刺激的反应及时程变化。采用组织化学方法,观察小鼠单次注射LPS入侧脑室后,Tomatolectin阳性的小胶质细胞于不同时间点在脑内的分布及表达的时程变化。LPS注射24h后,Tomatolectin组织化学染色显示血管内皮细胞、静息的和不同激活状态的小胶质细胞均呈阳性反应,其中Tomatolectin阳性的小胶质细胞明显被激活,2d时达表达高峰,巨噬细胞样的细胞和小胶质细胞呈现出肥大的、阿米巴样或杆状细胞等不同激活状态下的形态特征。这些激活的小胶质细胞主要分布于侧脑室周围的脑实质结构,如海马、隔区、胼胝体、纹状体,第三脑室周围的下丘脑及其它间脑结构。本结果提示:LPS能诱导小鼠脑室周围的脑实质内的小胶质细胞被激活,并上调小胶质细胞内Toma-tolectin的表达,这些细胞可能参与脑内刺激的免疫调节。

Cloning and Sequencing of a Lectin Protein Gene from the Roots of Sophora flavescens

A lectin protein(SFL) with molecular weight about 32 kD which markedly agglutinated rabbit and human red blood cells was purified from the roots of Sophora flavescens Ait. This protein, and apparently inhibited the growth of Fusarium vasinfectum Atk., Gibberella saubinetii (Mont.) Sacc., and Piricularia oryzae Cav. A set of degenerate PCR primer was synthesized according to the N-terminal sequence of the purified protein. The full-length cDNA coding the lectin was cloned by RT-PCR and 5'-RACE and sequenced (GenBank AF285121). The deduced amino acid sequence indicates that a preprotein with 284 amino acid residues is firstly translated and then processed to a mature protein with 254 amino acids. A N-Glycosylation site is the Asn 182 residue.

Identification of a Lectin Gene Induced in Rice in Response to Magnaporthe grisea Infection

By mRNA differential display, eight induced cDNAs were obtained from rice leaves infected with an incompatible race 131 of Magnaporthe grisea, and one of these cDNAs was highly similar to salt-induced mannose-binding lectin gene. Using this fragment as a probe, a full length cDNA was isolated from a nice cDNA library, which was constructed using mRNA from the incompatible race-infected leaves. Sequence analysis indicates that the cDNA encodes a protein of 15 kD with 145 amino, acids and shares 96% identity at nucleotide level with MRL and salT, but is identical to MRL at amino acid level. Genomic Southern blotting shows that there are two mannose-binding lectin genes in rice genome. Northern blotting analysis indicates that the gene was strongly and specifically induced in rice leaves infected with the incompatible race, suggesting that the lectin induction be involved in the defense of rice to M. grisea.

Lectin法分析uNK细胞在人妊娠母胎界面的分布变化

通过Lectin法分析uNK细胞在人妊娠早、晚期母胎界面的分布变化。结果发现:(1)在妊娠早期的蜕膜中,uNK细胞主要有两种形式,一种是成熟uNK细胞,细胞体积较大,胞浆和胞膜呈现强烈的棕黄色染色,分布于蜕膜的血管中。另一种是未成熟uNK细胞,细胞体积较小,胞核呈现黄色染色,分布于蜕膜细胞之间。(2)在妊娠早期的绒毛组织中,uNK主要是未成熟uNK,分布于绒毛间质之间。(3)与妊娠早期蜕膜的uNK细胞数相比,至妊娠晚期,蜕膜的uNK细胞数量明显减少(P<0.01)。(4)在妊娠晚期,绒毛组织不表达uNK细胞。结论:uNK细胞主要分布于子宫蜕膜组织,且随着妊娠的进展,其表达数量明显下降。这种时空性的表达变化可能与其在调控滋养层细胞的侵袭、血管重建及免疫耐受方面密切相关。

Transformation of Pea Lectin Gene and Parasponia Haemoglobin Gene into Rice and Their Expressions

Lectin and leghemoglobin in legumes play the important roles, respectively, in recognition of host plants to their rhizobial bacteria, and lowering the oxygen partial pressure around bacteroids and protecting nitrogenase from oxygen in symbiotic nitrogen-fixing nodules. In order to extend the host range of the rhizobial bacteria and to make them fix nitrogen in non-legumes, pea lectin gene (pl) and Parasponia hemoglobin gene ( phl,) have been constructed into a plant expression vector (pCBHUL) and the vector pCBHUL was introduced into rice calli from immature young embryos by particle bombardment. After the calli were regenerated into plantlets on the resistant-selecting media containing hygromycin, they were identified by PCR and Southern blot hybridization. It was indicated that the pi and phb genes were integrated into nucleic genome of the transformed rice plants. GUS activity and the product of the pi gene were determined by GUS staining, Western blot and in situ hybridization at translational level. Eighteen out of 40 plants resistant to hygromycin were positively identified by PCR analysis with the rate of 45%. The pi gene was expressed in 3 out of 18 plants with 17% and 7.5% in 40 plants. The results may provide a clue for exploring whether Rhizobium leguminosarum by. viceae could extend its host range and make the transgenic rice plants have the possibility of being symbiotic, or associative to nitrogen fixation.

Research on the Lectin in Muscle Tissue of Varicorhinus macrolepis

[Objective] The paper aimed at researching lectins in muscles of Varicorhinus macrolepis and providing scientific basis for researching the adaptation mechanism and immune response of V.macrolepis to environment,which were advantageous for the protection and reproduction of V.macrolepis.[Method] V.macrolepis was used as test materials for the hemagglutination test by dialdehyde fixation to prove the existence of lectins in muscle crude homogenate of Varicorhinus macrolepis and study the physical and chemical characters.[Result] Lectins in muscle crude homogenate of V.macrolepis had shown hemagglutination effects on erythrocytes of six types of animals and had the maximum hemagglutination activity against rabbit erythrocytes,which belonged to the S-type lectins with optimal pH ranged from 4 to 8 and optimal temperature at 60 ℃.Results from the saccharide inhibition test had indicated that the sucrose was the only kind of saccharide which had inhibited the hemagglutination,suggesting that sucrose had played an important role in the process of recognition and aggregation of lectins.[Conclusion] It had been speculated that the optimal pH ranges for thermal sensitivity and hemagglutination activity of lectins in different types of aquatic organisms were similar.

斑节对虾1种lectin基因的电子克隆及分析

以中国明对虾的c-lectin(DQ167572)基因为探针,搜索EST数据库,获得了日本对虾的1个lectin序列,通过电子克隆扩增到了该基因,并对基因进行了生物信息学分析。

蒙药嘎日迪-13对脑缺血大鼠不同时相海马中IL-1β IL-8、ICAM-1、P-selectin表达的影响

目的观察蒙药嘎日迪-13对脑缺血大鼠不同时相海马中IL-1β、IL-8、ICAM-1、P-selectin表达的影响。方法 360只雄性SD大鼠随机分为脑缺血模型组、假手术组、嘎日迪-13大、中、小剂量组,每组又随机分为6个时相组,灌胃给药,一次/d,连续27 d后,线栓法制备大鼠大脑中动脉栓塞模型,神经功能评分后免疫组化法测定海马IL-1β、IL-8、ICAM-1、P-selectin的表达。结果嘎日迪-13明显降低脑缺血大鼠神经功能评分,并明显降低脑缺血大鼠海马IL-1β、IL-8、ICAM-1、P-selectin的表达水平。结论蒙药嘎日迪-13对大鼠脑缺血有较好的保护作用,其机制可能与降低IL-1β、IL-8、ICAM-1、P-selectin等因子的表达水平有关。

豌豆早期结瘤素基因ENOD12A的克隆及与PsLectin基因双元表达载体的构建

采用PrimStar HS DNA聚合酶从豌豆基因组DNA中扩增出了豌豆早期结瘤素基因PsENOD12A.序列分析结果表明,所克隆的基因与GenBank公布的序列仅相差1个碱基,但推导的氨基酸序列没有改变.将PsENOD12A基因和豌豆凝集素基因psl重组进了双元表达载体.

MBL及其补体激活的LECTIN途径

MBL是一种血清C型凝集素 ,是机体先天免疫的重要分子之一 ,本文在简要总述MBL的结构和功能的基础上 ,对MBL参与的凝集素途径进行阐述。

中国明对虾C-型凝集素基因(Fclectin)的重组表达及活性分析

研究拟通过分析对虾C型凝集素的活性特点,探讨其在对虾先天免疫应答过程中的潜在功能以及在养殖生产实践中的应用。实验利用原核表达系统对中国明对虾C-型凝集素基因的两个串联的糖识别结构域(carbohydrate recognition domain,CRD)进行了重组表达,并通过纯化复性获得了重组目的蛋白(rFclectin-CRD1和rFclectin-CRD2)。活性分析结果显示,重组目的蛋白对多种病原菌有凝集和抑制生长的作用,并且具有Ca2+依赖活性;其凝集活性可被半乳糖、肽聚糖、脂多糖等多种病原相关分子模式所抑制,研究结果证实,Fclectin是一种典型的C-型凝集素,它可能作为中国明对虾先天免疫中重要的模式识别受体,在一定程度上参与了机体应答病原微生物的防御过程。