Mannose-binding Lectin Gene Research Articles

Association between mannose-binding-lectin gene and type 2 diabetic patients in Chinese population living in the northern areas of China

To investigate whether the mannose-binding-lectin 2 (MBL2) gene was associated with type 2 diabetes in the populations living the northern part of China. The study involved 318 type 2 diabetic patients and 448 normoglycemic controls. The variances of rs1800450, rs1800451 and rs11003125 were determined by the Multiplex SNaPshot method. Fasting blood-glucose, triglyceride and total cholesterol were also measured. All of these results were analyzed by logistic regression method. Linkage disequilibrium and Haplotype measures were computed in all samples using Haploview. There seemed no mutation on rs1800451 while the rs1800450 and rs11003125 polymorphism was consistent with Hardy-Weinberg expectations in both the case and the control groups. Genotypes and allele frequencies of rs1800450 as well as rs11003125 were observed (P = 0.006, P = 0.003) and (P = 0.010, P = 0.004), respectively. Data from logistic regression analysis revealed that factors as overweight, abdominal obesity, hypercholesterolemia, GG genotype frequencies of Exon1 rs1800450 polymorphism as well as (GC + CC) genotype frequencies of rs11003125 polymorphism in MBL2 conferred increased risks for type 2 diabetes. Haplotype analyses of the two SNPs (rs1800450, rs11003125) revealed similar effects as compared with the single SNP associations. Only haplotype constructed from GC alleles conferred increased trends for type 2 diabetes (OR = 2.21, 95%CI: 1.47 - 3.33, P = 0.000). Our result suggested that the Exon1 rs1800450 polymorphism and promoter region rs11003125 polymorphism in MBL2 gene were both associated with type 2 diabetes in the Chinese population living in the northern areas of China. The G allele of rs1800450 and C allele of rs11003125 might be the risk factors of type 2 diabetes.

Association of Herpes Zoster Infection With Clinical Characteristics and MBL2 Gene Polymorphisms in Chinese Children With Systemic Lupus Erythematosus

In the first part of this study, we analyzed clinical factors associated with pediatric-onset systemic lupus erythematosus (SLE), and patient susceptibility to herpes zoster (HZ). In the second part of this study, we characterized MBL2 genotype polymorphisms in pediatric-onset SLE patients and their possible associations with HZ. This 10-year prospective cohort study compared pediatric-onset SLE patients from Taiwan with and without histories of HZ. By using 2 years as a standard interval, patients with early-onset and late-onset of HZ were compared. MBL2 gene polymorphisms in exon 1 at codon 54, and in the promoter at the position -221 and -550, were tested immediately after patient enrollment. We initially enrolled 98 SLE patients, and analyzed complete clinical characteristics of 82 patients (35 patients with HZ, 47 patients without HZ). The incidence of HZ was higher in SLE patients who had methylprednisolone pulse therapy, cyclophosphamide pulse therapy, and received higher cumulative steroid dose (P < 0.05 for all 3). There were no significant associations of HZ with MBL2 genotype or serum level of mannose-binding lectin. Pediatric-onset SLE patients were highly susceptible to HZ, with an incidence of 35.7%. Patients given steroid, cyclophosphamide, and high cumulative steroid dose were more likely to have had HZ. Deficiency of serum mannose-binding lectin and MBL2 gene polymorphism were not associated with HZ.

Evolution of the FCN2 promoter polymorphism

Mannose-binding lectin (MBL) and the ficolins (Ficolin-1, Ficolin-2 and Ficolin-3) are soluble collagen-like proteins that are involved in innate immune defence. They bind sugar structures or acetylated compounds present on microorganisms and on dying host cells and they initiate activation of the lectin complement pathway in varying degrees. Common variant alleles situated both in promoter and structural regions of the human MBL gene (MBL2) influence the stability and the serum concentration of the protein. Although not as thoroughly investigated as the MBL2 gene polymorphisms the ficolin genes (FCNs) also exhibit genetic variations affecting both the serum concentration, stability and binding capacity of the corresponding proteins. Epidemiological studies have suggested that the genetically determined variations in MBL serum concentrations influence the susceptibility to and the course of different types of diseases, while the importance of the ficolins in general and the genetic variation in the FCNs genes in particular is still largely unresolved. This overview will summarize the current molecular knowledge of the human MBL2, FCN1, FCN2 and FCN3 genes.

Mannose-binding lectin 1 haplotypes influence serum MBL-A concentration, complement activity, and milk production traits in Chinese Holstein cattle

Mannose-binding lectin (MBL) is a member of the collectin protein family that binds a broad range of microorganisms and activates the lectin-complement pathway of innate immunity. MBL deficiency is associated with an increased risk for various infections and arises from five polymorphisms in the promoter and first exon of the MBL gene in humans. In this study, three novel single-nucleotide polymorphisms (SNPs) in the promoter region and two previously reported SNPs in exon 2 of the MBL1 gene were detected using PCR single-strand conformation polymorphism, restriction fragment length polymorphism, and DNA sequencing in 537 cattle from three Chinese breeds. Analysis of the genotypes and haplotypes was used to investigate the polymorphisms and their possible implications, especially their association with serum MBL-A levels, complement activity (CH50 and ACH50), and milk production traits was investigated. The g.2651G > A SNP in exon 2 affected the serum MBL-A concentrations and the serum CH50 values, whereas the g.-1330G > A SNP significantly affected CH50 and the somatic cell scores (SCSs). Statistical analysis revealed that cows with the ATGGC/ACAAC combined genotype and those with the AAGGT/ACGGT combined genotype exhibited the lowest and highest SCSs, respectively. Serum antibacterial activities were also conducted to verify the effect of the SNPs on resistance to mastitis pathogens. Results of real-time PCR showed that the liver of cows with clinical mastitis exhibited a higher MBL1 expression compared with healthy ones (P < 0.05). Findings of this study indicate that the MBL1 gene possibly contributes to bacterial infection resistance and can be used as a molecular marker of milk production traits to control mastitis.

Serum mannose-binding lectin (MBL) gene polymorphism and low MBL levels are associated with neonatal sepsis and pneumonia

The aim of this study was to determine the serum mannose-binding lectin (MBL) levels and the frequency of MBL gene polymorphisms in infants with neonatal sepsis. Between January 2008 and January 2010, a total of 93 infants were included in this study and 53 of them had neonatal sepsis diagnosis as study group and 40 infants who had no sepsis according to clinical and laboratory findings as control group. Serum MBL levels were found to be low in 17 of 93 infants. Eleven of them were in the sepsis group and six of them were in the control group. Serum MBL levels were significantly lower in infants with sepsis compared with the control group. Frequencies of genotype AB and BB were also significantly higher in the study group compared with the control group. Most importantly, presence of B allele of MBL exon 1 gene was found to be associated with an increased risk for neonatal sepsis. Additionally, in the study group, the mean serum MBL levels were found to be significantly lower in the premature infants compared with the term infants. Pneumonia, bronchopulmonary dysplasia (BPD) and intraventricular hemorrhage (IVH) were significantly higher in infants with MBL deficiency compared with infants with normal MBL levels. Low MBL levels and presence of B allele of MBL exon 1 gene were found to be important risk factors for development of both neonatal sepsis and pneumonia, especially in premature infants. Low MBL levels and MBL gene polymorphisms might also be associated with inflammation-related neonatal morbidities such as BPD and IVH.

Association between mannose-binding lectin and interleukin-1 receptor antagonist gene polymorphisms and recurrent vulvovaginal candidiasis

The influence of functional polymorphisms in the genes coding for mannose-binding lectin (MBL) and interleukin-1 receptor antagonist (IL-1ra) on recurrent vulvovaginal candidiasis (RVVC) were examined in an urban Brazilian population. DNA was isolated from buccal swabs of 100 women with RVVC and 100 control women and tested by gene amplification for a single nucleotide polymorphism in codon 54 of the MBL2 gene and for a length polymorphism in intron 2 of the IL1RN gene. Genotype and allele frequencies were compared between groups. The frequency of the variant MBL2 B allele, associated with reduced circulating and vaginal MBL concentrations, was 27.0% in RVVC and 8.5% in control women (p<.0001). The MBL2 B,B genotype was present in 12% of RVVC patients and 1% of controls (p=.0025). The IL1RN 2 allele frequency, associated with the highest level of unopposed IL-1β activity, was 24.0% in RVVC and 23.4% in controls. The IL1RN genotype distribution was also similar in both groups. Carriage of the MBL2 codon 54 polymorphism, but not the IL1RN length polymorphism, predisposes to RVVC in Brazilian women.

Mannose-binding Lectin Expression Genotype in Pediatric-onset Systemic Lupus Erythematosus: Associations with Susceptibility to Renal Disease and Protection Against Infections

To study possible associations between extended mannose-binding lectin (MBL) expression genotypes and clinical manifestations and infections in children with systemic lupus erythematosus (SLE). Clinical and laboratory variables for a cohort of 125 patients with pediatric-onset SLE were obtained by clinical examinations and chart reviews. Controls were 137 age-matched and sex-matched healthy children and adolescents. MBL gene polymorphisms were genotyped by polymerase chain reaction. Serum MBL concentrations were measured by ELISA. The frequencies of extended MBL expression genotypes did not differ between patients and controls. There were 82 patients with SLE who had high MBL expression genotypes and 43 who had medium and low MBL expression genotypes. Patients with the high MBL expression genotype had renal disorders more frequently than patients in the group with medium and low MBL expression genotypes [54/82 (65.9%) vs 18/43 (41.9%), respectively; p = 0.013] and fewer serious bacterial infections [22/82 (26.8%) vs 20/43 (46.5%); p = 0.030]. Using logistic regression for patients with SLE, a high MBL expression genotype was independently associated with renal disorders (OR 2.49, 95% CI 1.15-5.39, p = 0.021) and had a protective effect against serious bacterial infections (OR 0.29, 95% CI 0.12-0.71, p = 0.007). MBL levels decreased significantly when patients with active SLE reached an inactive stage (1.56 ± 0.55 μg/ml vs 1.08 ± 0.65 μg/ml; p = 0.001), but these levels were still higher than those in controls. Our findings suggest that a high MBL expression genotype is a risk factor for renal disorder, while it has a protective effect against infections. Serum MBL levels reflect SLE activity.

Characterization of a mannose-binding lectin from channel catfish (Ictalurus punctatus)

Mannose-binding lectin (MBL) is an important component of innate immunity capable of activating the lectin pathway of the complement system. A MBL gene was isolated from channel catfish (Ictalurus punctatus). The deduced protein contains a canonical collagen-like domain, a carbohydrate recognition domain (CRD), and a neck region similar to mammalian mannose-binding lectin. The catfish mannose-binding lectin CRD contains the EPN motif shown previously to mediate mannose specificity. The catfish mannose-binding lectin showed 30–43% identity with MBL protein sequences of rainbow trout, zebrafish, common carp, and goldfish, and 33–35% identity with sequences of mammalian species. In this study, while liver was the predominant source of mannose-binding lectin gene expression in healthy tissues, mannose-binding lectin expression in spleen rose sharply following challenge with a Gram-negative bacterium.

The significance of mannose-binding lectin gene polymorphisms on the risk of BK virus coinfection in women with human papillomavirus–positive cervical lesions

The simultaneous detection of oncogenic human papillomavirus (HPV) and BK virus (BKV) has been recently reported in cervical cancers, suggesting that these viruses may act together in the process of cell transformation; host genetic polymorphisms may also influence virus persistence/reactivation. To disclose a possible role of the gene encoding for the mannose-binding lectin, MBL2, in susceptibility to BKV infection, we analyzed functional polymorphisms in the first exon of MBL2 in women stratified for the presence/absence of BKV and affected by different grades of HPV-induced cervical precancerous lesions. All BKV-positive samples were also HPV positive (HPV 16), and all presented with high-grade squamous intraepithelial lesions. The MBL2 A allele was significantly more frequent in BKV-negative patients than in BKV-positive patients. These data indicate a possible role for the A allele in conferring protection to BKV infection in high-risk HPV-positive women (odds ratio 0.40, 95% confidence interval 0.20–0.85, p = 0.01).

Association of mannose-binding lectin-2 gene polymorphism with the development of hepatitis C-induced hepatocellular carcinoma

Development of end-stage liver and graft disease is suspected to be partially determined by the individual genetic background. Mannose-binding lectin (MBL) is an important immunomodulatory factor, which is supposed to be involved in complement activation and oncogenesis. Genetic polymorphisms of MBL-2 alter MBL functionality. The aim of our study was to determine the prevalence of MBL-2 polymorphism (rs7096206) in hepatitis C virus (HCV)-induced hepatocellular carcinoma (HCC) based on histological analysis of explanted livers in patients undergoing liver transplantation (LT). One hundred and seventy-seven patients, who underwent LT for HCV-induced liver disease, were genotyped for MBL-2 by TaqMan genotyping assay. Sixty-two patients with histologically confirmed HCC were compared with 115 patients without HCC. MBL-2 genotypes were corelated with the growth patern, tumour size and pretransplant α-fetoprotein (AFP) level of HCC patients. The prevalence of GG/GC genotypes was significantly higher among HCC patients compared with tumour-free explanted livers (P = 0.004; odds ratio 2.5; 1.3-4.8). GG/GC genotype group was significantly associated with the size of HCC (P = 0.022), higher pretransplant AFP level (P = 0.010) and bilobar tumour growth (P = 0.038). Furthermore, CC genotype was found to be significantly more frequent in AFP-negative HCCs (P = 0.002). Mannose-binding lectin-2 polymorphism seems to be involved in the development of pretransplant HCV-induced HCC and should be further investigated as potential risk factor for HCV-associated carcinogenesis.

Mannose binding lectin gene (MBL2) functional polymorphisms are associated with systemic lupus erythematosus in southern Brazilians

Susceptibility to systemic lupus erythematosus (SLE) has been associated with immunologic, environmental, and genetic factors. To uncover a possible association between MBL2 gene polymorphisms and SLE, we analyzed functional polymorphisms in the promoter and first exon of the MBL2 gene in 134 Brazilian SLE patients and 101 healthy controls. Genotype and allele frequencies of MBL2 A/O polymorphism were significantly different between patients and controls, and the O allele was associated with an increased risk of SLE. An association between low mannose binding lectin (MBL) producer combined genotypes and increased risk for SLE was also reported. Furthermore, when stratifying SLE patients according to clinical and laboratory data, an association between the A/O genotype and nephritic disorders and between the X/Y genotype and antiphospholipid syndrome was evident. Combined genotypes responsible for low MBL production were more frequently observed in SLE patients with nephritis. Our results indicate MBL2 polymorphisms as possible risk factors for SLE development and disease-related clinical manifestations.

LY96, UPKIB Mutations and TLR4, CD14, MBL Polymorphisms in Children with Urinary Tract Infection

To evaluate genetic variations of innate immune system such as mannose binding lectin (MBL), Toll like receptor 4 (TLR4), CD14, LY96 (MD2) and Uroplakin 1B (UPK1B) genes in children with recurrent urinary tract infection (UTI). The study included 30 children with recurrent UTI and 30 healthy controls. Blood was drawn and analysed for genetic polymorphisms of MBL, TLR4 and CD14 genes by the PCR-RFLP method. Direct DNA sequencing analysis was performed for LY96 and UPK 1B gene mutation in 10 children from UTI group and 5 children from control group. TLR4 gene Thr399Ile polymorphism was not observed in any child. Genotype distribution and allele frequency of Asp299Gly polymorphism was similar in both groups (p = 0.55). Codon 54 polymorphism of the MBL gene was similar in UTI and control groups (p = 0.49). -159 CC/CT/TT genotypes of CD14 gene was similar between the two groups (p = 0.14). UPK1B and LY96 gene DNA sequence analysis was similar in UTI and control groups. This study is the first study in which different parts of the innate immune system were evaluated in UTI etiopathogenesis in Turkish children. The results did not point out a significant role of any of the genes evaluated in this study.

The role of mannose-binding lectin gene polymorphisms in susceptibility to HIV-1 infection in Southern Brazilian patients

This study investigates the role of mannose-binding lectin (MBL) in the susceptibility to HIV-1 infection analyzing polymorphisms located at the MBL2 promoter and exon 1 regions. The prevalence of MBL2 variant alleles was investigated in 410 HIV-1-infected patients from the South Brazilian HIV cohort and in 345 unexposed uninfected healthy individuals. The promoter variants were genotyped using polymerase chain reaction with sequence-specific primers (PCR-SSP) and exon 1 variants were analyzed by real-time PCR using a melting temperature assay and were confirmed by PCR-restriction fragment length polymorphism (RFLP). MBL2 genotypic and allelic frequencies were compared between HIV-1-infected patients and controls using the chi-squared tests. The analyses were performed subdividing the individuals according to their ethnic origin. Among Euro-derived individuals a higher frequency of the LX/LX genotype was observed in patients when compared to controls (P < 0.001). The haplotypic analysis also showed a higher frequency of the haplotypes associated with lower MBL levels among HIV-1-infected patients (P = 0.0001). Among Afro-derived individuals the frequencies of LY/LY and HY/HY genotypes were higher in patients when compared to controls (P = 0.009 and P = 0.02). An increased frequency of MBL2 genotypes associated with low MBL levels was observed in Euro-derived patients, suggesting a potential role for MBL in the susceptibility to HIV-1 infection in Euro-derived individuals.

Mannose-binding lectin and Ficolin-2 gene polymorphisms predispose to cytomegalovirus (re)infection after orthotopic liver transplantation

The lectin pathway of complement activation is a crucial effector cascade of the innate immune response to pathogens. Cytomegalovirus (CMV) infection occurs frequently in immunocompromised patients after orthotopic liver transplantation (OLT). Single-nucleotide polymorphisms (SNPs) in the lectin pathway genes determine their liver-derived protein level and functional activity. We examined the association between these SNPs and the risk for CMV infection in OLT. OLT patients (n = 295) were genotyped for recipient and donor SNPs in mannose-binding lectin (MBL2), Ficolin-2 (FCN2) and MBL-associated serine protease (MASP2) genes. Combined analysis of independently associated variant MBL2 [HR 1.65, p<0.02] and wild-type FCN2 [1.85; p<0.02] SNPs in the donor liver showed an increased risk of CMV infection for either and both risk genotypes [HR 2.02 and HR 3.26, respectively, p = 0.004], especially in CMV Donor-/Recipient+ (D-/R+) patients [HR 4.7 and HR 10.0, respectively, p = 0.01]. A genetic donor-recipient mismatch for MBL2 and FCN2 increased the CMV risk independently, also combined [HR 5.35; p<0.001], particularly in CMV D-/R+ patients [HR 16.6; p = 0.009]. Multivariate Cox analysis showed a consistent stepwise increase in CMV infection risk with the gene profile of the donor [up to HR 2.77; p<0.005] and the combined MBL2 and FCN2 donor-recipient mismatch profile [up to HR 4.57; p<0.001], independent from donor-recipient CMV serostatus, also at higher CMV (re)infection cut-off values. MBL2 and FCN2 risk alleles of donor liver and recipient constitute independent risk factors for CMV infection after OLT. Patients with these risk genes probably need intensified CMV monitoring and anti-viral therapy.

Characterization of mannose-binding lectin plasma levels and genetic polymorphisms in HIV-1-infected individuals

The present study investigated the association between mannose-binding lectin (MBL) gene polymorphism and serum levels with infection by HIV-1. Blood samples (5 mL) were collected from 97 HIV-1-infected individuals resident in Belém, State of Pará, Brazil, who attended the Special Outpatient Unit for Infections and Parasitic Diseases (URE-DIPE). CD4+ T-lymphocyte count and plasma viral load were quantified. A 349bp fragment of exon 1 of the MBL was amplified via PCR, using genomic DNA extracted from controls and HIV-1-infected individuals, following established protocols. MBL plasma levels of the patients were quantified using an enzyme immunoassay kit. Two alleles were observed: MBL*O, with a frequency of 26.3% in HIV-1-infected individuals; and the wild allele MBL*A (73.7%). Similar frequencies were observed in the control group (p > 0.05). Genotype frequencies were distributed according to the Hardy-Weinberg equilibrium in both groups. Mean MBL plasma levels varied by genotype, with statistically significant differences between the AA and AO (p < 0.0001), and AA and OO (p < 0.001) genotypes, but not AO and OO (p = 0.17). Additionally, CD4+ T-lymphocytes and plasma viral load levels did not differ significantly by genotype (p > 0.05). The results of this study do not support the hypothesis that MBL gene polymorphism or low plasma MBL concentrations might have a direct influence on HIV-1 infection, although a broader study involving a large number of patients is needed.

Association Of Mannose Binding Lectin (MBL) Gene Mutations With Other Pathway Defects Spanning Innate And Adaptive Immune Responses

RATIONALE: Many patients with repeat infections or autoimmunity have defects in multiple immune pathways which have not been properly analyzed or understood. The multi-locus gene inheritance of the immune system makes these multiple immune deficiency patients' diagnosis and treatment challenging.

Structural gene variants in the porcine mannose-binding lectin 1 (MBL1) gene are associated with low serum MBL-A concentrations

Mannose-binding lectin (MBL) is a collagenous lectin that kills a wide range of pathogenic microbes through complement activation. The MBL1 and MBL2 genes encode MBL-A and MBL-C, respectively. MBL deficiency in humans is associated with higher susceptibility to viral as well as bacterial infections. A number of single nucleotide polymorphisms (SNP) have been identified in the collagen-like domain of the human MBL gene, of which several are strongly associated with decreased concentrations of MBL in serum. In this study, we have identified a number of SNPs in the porcine MBL-A gene. Sequence comparisons identified a total of 14 SNPs, eight of which were found in exons and six in introns. Four of the eight exon-located SNPs were non-synonymous. Sequence data from several Duroc and Landrace pigs identified four different haplotypes. One haplotype was found in Duroc pigs only, and three haplotypes were found in the Landrace pigs. One of the identified haplotypes was associated with low concentration of MBL-A in serum. The concentration of MBL-A in serum was further assessed in a large number of Duroc and Landrace boars to address its correlation with disease frequency. The MBL-A concentration in Duroc boars showed one single population, whereas Landrace boars showed four distinct populations for MBL-A concentration. The Landrace boars were finally assessed for disease incidence, and the association with the concentration of MBL-A in serum was investigated. No association between MBL and disease incidence was found in this study.

Polymorphisms in mannose-binding lectin (MBL) gene and their association with MBL protein levels in serum in the Hu sheep

Mannose-binding lectin (MBL) is the archetypical pathogen recognition protein of the innate immune defence. In humans, three frequently occurring single nucleotide polymorphisms (SNPs) in the coding region of MBL gene are associated with the abnormal polymerization, decreased serum concentration and strongly impaired function of MBL protein. To understand whether or not SNPs in MBL gene are associated with serum concentration of MBL in sheep, we investigated 105 individuals of the Hu sheep by PCR single-strand conformation polymorphism (SSCP) analysis, DNA sequencing, and enzyme-linked immunosorbent assay. SSCP analyses of PCR amplicons from a 194-bp section of the exon-I region of the MBL gene revealed four patterns: A, B, C and D. In comparison with the sequences of the full-length MBL gene of sheep (GenBank accession numbers FJ977629 and AM933378; reference sequence hereafter), pattern A has a 3-bp deletion, a 6-bp deletion and 42 SNPs. Pattern B has 3 SNPs, pattern C has 2 SNPs, whereas pattern D is identical to the reference sequence. Twenty-four of the 47 SNPs of the four patters are synonymous whereas the other 23 SNPs are non-synonymous. The two deletions in the pattern A result in deletions of amino acids but there are no frame shifts in the putative MBL protein. The concentration of MBL protein in serum ranges from 1571 to 3657μg/L in the Hu sheep. Our statistic analyses showed that patterns A and B are associated with reduced MBL protein level in serum, whereas pattern C is associated with increased MBL protein level in serum (P<0.05) in the Hu sheep.

The Pepper Mannose-Binding Lectin Gene CaMBL1 Is Required to Regulate Cell Death and Defense Responses to Microbial Pathogens

Plant mannose-binding lectins (MBLs) are crucial for plant defense signaling during pathogen attack by recognizing specific carbohydrates on pathogen surfaces. In this study, we isolated and functionally characterized a novel pepper (Capsicum annuum) MBL gene, CaMBL1, from pepper leaves infected with Xanthomonas campestris pv vesicatoria (Xcv). The CaMBL1 gene contains a predicted Galanthus nivalis agglutinin-related lectin domain responsible for the recognition of high-mannose N-glycans but lacks a middle S-locus glycoprotein domain and a carboxyl-terminal PAN-Apple domain. The CaMBL1 protein exhibits binding specificity for mannose and is mainly localized to the plasma membrane. Immunoblotting using a CaMBL1-specific antibody revealed that CaMBL1 is strongly expressed and accumulates in pepper leaves during avirulent Xcv infection. The transient expression of CaMBL1 induces the accumulation of salicylic acid (SA), the activation of defense-related genes, and the cell death phenotype in pepper. The G. nivalis agglutinin-related lectin domain of CaMBL1 is responsible for cell death induction. CaMBL1-silenced pepper plants are more susceptible to virulent or avirulent Xcv infection compared with unsilenced control plants, a phenotype that is accompanied by lowered reactive oxygen species accumulation, reduced expression of downstream SA target genes, and a concomitant decrease in SA accumulation. In contrast, CaMBL1 overexpression in Arabidopsis (Arabidopsis thaliana) confers enhanced resistance to Pseudomonas syringae pv tomato and Alternaria brassicicola infection. Together, these data suggest that CaMBL1 plays a key role in the regulation of plant cell death and defense responses through the induction of downstream defense-related genes and SA accumulation after the recognition of microbial pathogens.

The first report described as an important study: The association of mannose-binding lectin gene 2 polymorphisms in children with down syndrome

BACKGROUND:Mannose-binding lectin gene 2 (MBL2) plays a very important role in the first line of host immune response in Down syndrome (DS). The importance of MBL2 gene polymorphisms in children with DS is unclear, and no research has addressed MBL2 gene polymorphisms in patients with DS. This is the first report describing an important association between MBL2 gene polymorphisms and infections in children with DS.MATERIALS AND METHODS:We compared the frequency of single-nucleotide polymorphisms (SNPs) at two codons of the MBL2 gene in a cross sectional cohort of 166 children with DS and 229 controls. Polymorphisms at codons 54 (GGC→GAC) and 57 (GGA→GAA) in exon 1 of the MBL2 gene were typed by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique using the restriction enzymes BshN1 (derivated from Bacillus sphaericus) and MboII (derivated from Moraxella bovis), respectively.RESULTS:MBL2 codon 54 GA genotype frequency was found to be lower in patients with DS (22.9%) than those of healthy controls (35.8%), differences were statistically significant (OR = 0.532, 95% CI = 0.339-0.836, P = 0.008). On the other hand, codon 57 polymorphism in the MBL2 gene was detected in none of the DS patients, but only one person in the control group showed codon 57 GA genotype (OR = 1.004, 95% CI = 0.996-1.013, P = 1.000).CONCLUSION:Our data provides an evidence for the first time that a homozygote or heterozygote for the variant, MBL2 alleles, is not associated with infections in patients with DS, and do not influence the incidence of infections.