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Osthoff M, Trendelenburg M. Impact of mannose-binding lectin deficiency on radiocontrast-induced renal dysfunction. BIOMED RESEARCH INTERNATIONAL 2013; 2013:962695. [PMID: 24386641 PMCID: PMC3872394 DOI: 10.1155/2013/962695] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 11/26/2013] [Indexed: 12/17/2022]
Abstract
Contrast-induced nephropathy (CIN) is the third leading cause of acute renal failure in hospitalized patients. Endothelial dysfunction, renal medullary ischemia, and tubular toxicity are regarded as the most important factors in the pathogenesis of CIN. Mannose-binding lectin (MBL), a pattern recognition protein of the lectin pathway of complement, has been found to aggravate and mediate tissue damage during experimental renal ischemia/reperfusion (I/R) injury which was alleviated by inhibition with C1 inhibitor, a potent MBL, and lectin pathway inhibitor. In this paper, we highlight the potential role of MBL in the pathogenesis of human CIN. In experimental I/R models, MBL was previously found to induce tubular cell death independent of the complement system. In addition, after binding to vascular endothelial cells, MBL and its associated serine proteases were able to trigger a proinflammatory reaction and contribute to endothelial dysfunction. In humans, urinary MBL was increased after administration of contrast media and in individuals with CIN. Moreover, individuals with normal/high MBL levels were at increased risk to develop radiocontrast-induced renal dysfunction. Hence, MBL and the lectin pathway seem to be a promising target given that a licensed, powerful, human recombinant inhibitor exits to be added to the scarce armamentarium currently available for prophylaxis of CIN.
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Affiliation(s)
- Michael Osthoff
- Department of Infectious Diseases, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland
| | - Marten Trendelenburg
- Laboratory of Clinical Immunology, Department of Biomedicine, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland
- Clinic for Internal Medicine, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland
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Potlukova E, Freiberger T, Limanova Z, Jiskra J, Telicka Z, Bartakova J, Springer D, Vitkova H, Trendelenburg M. Association between low levels of Mannan-binding lectin and markers of autoimmune thyroid disease in pregnancy. PLoS One 2013; 8:e81755. [PMID: 24339961 PMCID: PMC3858249 DOI: 10.1371/journal.pone.0081755] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 10/16/2013] [Indexed: 01/22/2023] Open
Abstract
Functional deficiency of mannan-binding lectin (MBL) has been associated with adverse pregnancy outcome. Adverse events during pregnancy have also been described in women with autoimmune thyroid diseases (AITD), and thyroid hormones have been shown to influence serum levels of MBL. Therefore, the aim of this study was to analyse the impact of MBL-deficiency on the outcome of pregnancy in relation to the presence of AITD. Almost one year after delivery, we assessed serum MBL levels and MBL2-genotypes in 212 women positively screened for AITD in pregnancy. In 103 of these women, we could also measure MBL levels in frozen serum samples from the 9-12th gestational week, obtaining 96 pairs of MBL values (pregnancy vs. follow-up). As controls, 80 sera of pregnant women screened negatively for AITD were used. MBL2-genotyping was performed using multiplex PCR. Women with thyroid dysfunction and/or thyroid peroxidase antibodies (TPOAb) had lower MBL levels during pregnancy than controls, (3275 vs. 5000 ng/ml, p<0.05). The lowest levels were found in women with elevated thyroid-stimulating hormone (TSH) levels in the absence of TPOAb (2207 ng/ml; p<0.01 as compared to controls). MBL2 genotype distribution did not differ between subgroups. At a median follow-up period of 17 months (range: 3–78 months) after delivery, median MBL level had decreased further to 1923 ng/ml (p<0.0001) without significant changes in TSH. In an explorative survey, functional MBL-deficiency was neither linked to a history of spontaneous abortion, nor other obstetric complications, severe infections throughout life/pregnancy or antibiotics use in pregnancy. In conclusion, hypothyroidism during pregnancy is associated with decreased MBL levels, and the levels decreased further after delivery.
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Affiliation(s)
- Eliska Potlukova
- Third Department of Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Tomas Freiberger
- Centre for Cardiovascular Surgery and Transplantation, Molecular Genetics Laboratory, Brno, Czech Republic, and Ceitec and Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Zdenka Limanova
- Third Department of Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Jan Jiskra
- Third Department of Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Zdenek Telicka
- Third Department of Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Jana Bartakova
- Third Department of Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Drahomira Springer
- Institute of Clinical Biochemistry and Laboratory Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Hana Vitkova
- Third Department of Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Marten Trendelenburg
- Laboratory of Clinical Immunology, Department of Biomedicine, University Hospital Basel, Switzerland
- * E-mail:
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Abstract
Human mannose-binding lectin (MBL) encoded by the MBL2 gene is a pattern recognition protein and has been associated with many infectious diseases, including malaria. We sought to investigate the contribution of functional MBL2 gene variations to Plasmodium falciparum malaria in well-defined cases and in matched controls. We resequenced the 8.7 kb of the entire MBL2 gene in 434 individuals clinically classified with malaria from regions of India where malaria is endemic. The study cohort included 176 patients with severe malaria, 101 patients with mild malaria, and 157 ethnically matched asymptomatic individuals. In addition, 830 individuals from 32 socially, linguistically, and geographically diverse endogamous populations of India were investigated for the distribution of functional MBL2 variants. The MBL2 -221C (X) allelic variant is associated with increased risk of malaria (mild malaria odds ratio [OR] = 1.9, corrected P value [P(Corr)] = 0.0036; severe malaria OR = 1.6, P(Corr) = 0.02). The exon1 variants MBL2*B (severe malaria OR = 2.1, P(Corr) = 0.036; mild versus severe malaria OR = 2.5, P(Corr) = 0.039) and MBL2*C (mild versus severe malaria OR = 5.4, P(Corr) = 0.045) increased the odds of having malaria. The exon1 MBL2*D/*B/*C variant increased the risk for severe malaria (OR = 3.4, P(Corr) = 0.000045). The frequencies of low MBL haplotypes were significantly higher in severe malaria (14.2%) compared to mild malaria (7.9%) and asymptomatic (3.8%). The MBL2*LYPA haplotypes confer protection, whereas MBL2*LXPA increases the malaria risk. Our findings in Indian populations demonstrate that MBL2 functional variants are strongly associated with malaria and infection severity.
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Abstract
Despite considerable advances in the understanding of the pathogenesis of meningococcal disease, this infection remains a major cause of morbidity and mortality globally. The role of the complement system in innate immune defenses against invasive meningococcal disease is well established. Individuals deficient in components of the alternative and terminal complement pathways are highly predisposed to invasive, often recurrent meningococcal infections. Genome-wide analysis studies also point to a central role for complement in disease pathogenesis. Here we review the pathophysiologic events pertinent to the complement system that accompany meningococcal sepsis in humans. Meningococci use several often redundant mechanisms to evade killing by human complement. Capsular polysaccharide and lipooligosaccharide glycan composition play critical roles in complement evasion. Some of the newly described protein vaccine antigens interact with complement components and have sparked considerable research interest.
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Affiliation(s)
- Lisa A Lewis
- Division of Infectious Diseases and Immunology; University of Massachusetts Medical School; Worcester, MA USA
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology; University of Massachusetts Medical School; Worcester, MA USA
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Genetic variation and cerebrospinal fluid levels of mannose binding lectin in pneumococcal meningitis patients. PLoS One 2013; 8:e65151. [PMID: 23741476 PMCID: PMC3669246 DOI: 10.1371/journal.pone.0065151] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 04/23/2013] [Indexed: 01/01/2023] Open
Abstract
It has been suggested that genetic variants in mannose binding lectin (MBL2) influence susceptibility and outcome of invasive pneumococcal disease. We assessed the influence of genetic variation in MBL2 on susceptibility, outcome and causative serotype of pneumococcal meningitis in a prospective nationwide cohort study including 299 white patients and 216 controls. We assessed functionality of the genetic polymorphisms by measuring levels of MBL, C3a, iC3b, C5a and sC5b-9 in cerebrospinal fluid. We also performed a meta-analysis of studies on MBL2 polymorphisms and susceptibility to invasive pneumococcal disease. The risk of contracting pneumococcal meningitis was substantially increased for white individuals homozygous with the defective MBL2 0/0 genotype (odds ratio [OR] 8.21, 95% confidence interval [CI] 1.05–64.1; p = 0.017). CSF MBL levels were significantly lower in patients with the A/0 and 0/0 genotype compared to homozygotes for the wild-type alleles (A/A; p<0.001). CSF MBL levels were positively correlated with C3a and iC3b levels, indicating complement activation by the lectin pathway. The effect of MBL2 genetic variants on susceptibility remained robust in a meta-analysis including 5 studies with 287 patients (OR 2.33, 99% CI 1.39–3.90). We conclude that MBL2 polymorphisms influence CSF MBL levels and substantially increase the risk of pneumococcal meningitis.
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Kovacs M, Papp M, Lakatos PL, Jacobsen S, Nemes E, Polgar M, Solyom E, Bodi P, Horvath A, Molnar K, Szabo D, Cseh A, Muller KE, Dezsofi A, Arato A, Veres G. Low mannose-binding lectin (MBL) is associated with paediatric inflammatory bowel diseases and ileal involvement in patients with Crohn disease. J Crohns Colitis 2013; 7:134-41. [PMID: 22504031 DOI: 10.1016/j.crohns.2012.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2011] [Revised: 03/11/2012] [Accepted: 03/12/2012] [Indexed: 02/08/2023]
Abstract
BACKGROUND Mannose-binding lectin (MBL) is a pattern-recognition molecule of the innate immune system and may be involved in the pathogenesis of inflammatory bowel disease (IBD). Our aim was to assess the prevalence of MBL deficiency in a cohort of patients with paediatric-onset IBD and study whether it is associated with the clinical manifestations, serum antibody formation, or genetic factors. METHODS This prospective study included 159 paediatric patients (mean age: 14.0 years) with IBD [107 patients with Crohn disease (CD) and 52 patients with ulcerative colitis (UC)]. Furthermore, 95 controls were investigated. Serum samples were determined for MBL by enzyme-linked immunosorbent assay (ELISA) and for serologic markers [autoantibodies against Saccharomyces cerevisiae (ASCA) and perinuclear components of neutrophils (pANCA)] by indirect immunofluorescent assay. NOD2/CARD15 variants were tested by polymerase chain reaction/restriction fragment length polymorphism. RESULTS The MBL serum concentration was significantly lower in IBD patients(both with CD and UC) compared to controls (IBD, p=0.007, CD, p=0.04, UC p=0.004). Prevalence of low MBL level (<500 ng/mL) was significantly higher in both CD and UC groups compared to controls (p=0.002 and p=0.006). Furthermore, low MBL level was associated with isolated ileal involvement (p=0.01) and MBL deficiency (<100 ng/mL) with male gender (p=0.004) in patients with CD. We failed to confirm any correlation between MBL deficiency and serum autoantibodies or NOD2/CARD15 variants. CONCLUSIONS Our results suggest that low MBL associated with paediatric-onset IBD and ileal CD may be considered an additional marker of the IBD pathogenesis.
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Affiliation(s)
- Marta Kovacs
- Department of Paediatrics, Petz Aladár County and Teaching Hospital, Győr, Hungary
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Non-HLA gene polymorphisms and their implications on dengue virus infection. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2013. [DOI: 10.1016/j.ejmhg.2012.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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Albert RK, Connett J, Curtis JL, Martinez FJ, Han MK, Lazarus SC, Woodruff PG. Mannose-binding lectin deficiency and acute exacerbations of chronic obstructive pulmonary disease. Int J Chron Obstruct Pulmon Dis 2012; 7:767-77. [PMID: 23226013 PMCID: PMC3514010 DOI: 10.2147/copd.s33714] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Indexed: 12/23/2022] Open
Abstract
Background: Mannose-binding lectin is a collectin involved in host defense against infection. Whether mannose-binding lectin deficiency is associated with acute exacerbations of chronic obstructive pulmonary disease is debated. Methods: Participants in a study designed to determine if azithromycin taken daily for one year decreased acute exacerbations had serum mannose-binding lectin concentrations measured at the time of enrollment. Results: Samples were obtained from 1037 subjects (91%) in the trial. The prevalence of mannose-binding lectin deficiency ranged from 0.5% to 52.2%, depending on how deficiency was defined. No differences in the prevalence of deficiency were observed with respect to any demographic variable assessed, and no differences were observed in time to first exacerbation, rate of exacerbations, or percentage of subjects requiring hospitalization for exacerbations in those with deficiency versus those without, regardless of how deficiency was defined. Conclusion: In a large sample of subjects with chronic obstructive pulmonary disease selected for having an increased risk of experiencing an acute exacerbation of chronic obstructive pulmonary disease, only 1.9% had mannose-binding lectin concentrations below the normal range and we found no association between mannose-binding lectin concentrations and time to first acute exacerbation or frequency of acute exacerbations during one year of prospective follow-up.
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Affiliation(s)
- Richard K Albert
- Medicine Service, Denver Health and Department of Medicine, University of Colorado Denver, USA.
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Rothfuchs AG, Roffê E, Gibson A, Cheever AW, Ezekowitz RAB, Takahashi K, Steindel M, Sher A, Báfica A. Mannose-binding lectin regulates host resistance and pathology during experimental infection with Trypanosoma cruzi. PLoS One 2012; 7:e47835. [PMID: 23139754 PMCID: PMC3490958 DOI: 10.1371/journal.pone.0047835] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 09/21/2012] [Indexed: 01/19/2023] Open
Abstract
Mannose-binding lectin (MBL) is a humoral pattern-recognition molecule important for host defense. Although recent genetic studies suggest an involvement of MBL/MASP2-associated pathways in Chagas’ disease, it is currently unknown whether MBL plays a role in host resistance to the intracellular protozoan Trypanosoma cruzi, the causative agent of Chagas’ disease. In this study we employed MBL−/− mice to assess the role of MBL in resistance to experimental infection with T. cruzi. T. cruzi infection enhanced tissue expression of MBL both at the mRNA and protein level. Similarly, symptomatic acute Chagas’ disease patients displayed increased serum concentrations of MBL compared to patients with indeterminate, asymptomatic forms of the disease. Furthermore, increased parasite loads in the blood and/or tissue were observed in MBL−/− mice compared to WT controls. This was associated with reduced systemic levels of IL-12/23p40 in MBL−/− mice. Importantly, MBL−/− mice infected with a cardiotropic strain of T. cruzi displayed increased myocarditis and cardiac fibrosis compared to WT controls. The latter was accompanied by elevated hydroxyproline content and mRNA levels of collagen-1 and -6 in the heart. These observations point to a previously unappreciated role for MBL in regulating host resistance and cardiac inflammation during infection with a major human pathogen.
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Affiliation(s)
- Antonio Gigliotti Rothfuchs
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden
- * E-mail: (AGR); (AB)
| | - Ester Roffê
- Molecular Signaling Section, Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Amanda Gibson
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Allen W. Cheever
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Biomedical Research Institute, Rockville, Maryland, United States of America
| | - R. Alan B. Ezekowitz
- Laboratory of Developmental Immunology, Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kazue Takahashi
- Laboratory of Developmental Immunology, Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Mario Steindel
- Department of Microbiology, Immunology and Parasitology, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Alan Sher
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - André Báfica
- Department of Microbiology, Immunology and Parasitology, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
- * E-mail: (AGR); (AB)
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Osthoff M, Piezzi V, Klima T, Christ A, Marana I, Hartwiger S, Breidthardt T, Marenzi G, Trendelenburg M, Mueller C. Impact of mannose-binding lectin deficiency on radiocontrast-induced renal dysfunction: a post-hoc analysis of a multicenter randomized controlled trial. BMC Nephrol 2012; 13:99. [PMID: 22938690 PMCID: PMC3471006 DOI: 10.1186/1471-2369-13-99] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 08/27/2012] [Indexed: 01/20/2023] Open
Abstract
Background Local renal ischemia is regarded as an important factor in the development of contrast-induced nephropathy (CIN). Mannose-binding lectin (MBL) is involved in the tissue damage during experimental ischemia/reperfusion injury of the kidneys. The aim of the present study was to investigate the association of MBL deficiency with radiocontrast-induced renal dysfunction in a large prospective cohort. Methods 246 patients with advanced non–dialysis-dependent renal dysfunction who underwent radiographic contrast procedures were included in the study. Baseline serum MBL levels were analyzed according to the occurrence of a creatinine-based (increase of ≥0.5 mg/dL or ≥25% within 48 hours) or cystatin C-based (increase of ≥10% within 24 hours) CIN. Results The incidence of creatinine-based and cystatin C-based CIN was 6.5% and 24%, respectively. MBL levels were not associated with the occurrence of creatinine-based CIN. However, patients that experienced a cystatin C increase of ≥10% showed significantly higher MBL levels than patients with a rise of <10% (median 2885 (IQR 1193–4471) vs. 1997 (IQR 439–3504)ng/mL, p = 0.01). In logistic regression analysis MBL deficiency (MBL levels≤500 ng/ml) was identified as an inverse predictor of a cystatin C increase ≥10% (OR 0.34, 95% CI 0.15-0.8, p = 0.01). Conclusion MBL deficiency was associated with a reduced radiocontrast-induced renal dysfunction as reflected by the course of cystatin C. Our findings support a possible role of MBL in the pathogenesis of CIN.
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Affiliation(s)
- Michael Osthoff
- Laboratory of Clinical Immunology, Department of Biomedicine, University Hospital Basel, Basel, Switzerland
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Reiber H, Padilla-Docal B, Jensenius JC, Dorta-Contreras AJ. Mannan-binding lectin in cerebrospinal fluid: a leptomeningeal protein. Fluids Barriers CNS 2012; 9:17. [PMID: 22889364 PMCID: PMC3487976 DOI: 10.1186/2045-8118-9-17] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/30/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mannan-binding lectin (MBL), a protein of the innate immune response is attracting increasing clinical interest, in particularly in relation to its deficiency. Due to its involvement in brain diseases, identifying the source of MBL in CSF is important. Analysis of cerebrospinal fluid (CSF) can provide data that discriminates between blood-, brain-, and leptomeninges-derived proteins. To detect the source of MBL in CSF we need to consider three variables: the molecular size-dependent concentration gradient between CSF and blood, the variation in transfer between blood and CSF, and the CSF MBL concentration correlation with the albumin CSF/serum quotient (QAlb), i.e., with CSF flow rate. METHODS MBL was assayed in samples of CSF and serum with an ELISA, coated with anti MBL antibodies. Routine parameters such as albumin-, immunoglobulin- CSF/serum quotients, oligoclonal IgG and cell count were used to characterize the patient groups. Groups comprised firstly, control patients without organic brain disease with normal CSF and normal barrier function and secondly, patients without inflammatory diseases but with increased QAlb, i.e. with a blood CSF barrier dysfunction. RESULTS MBL concentration in CSF was at least five-fold higher than expected for a molecular-size-dependent passage from blood. Secondly, in a QIgM/QAlb quotient diagram (Reibergram) 9/13 cases showed an intrathecal fraction in some cases over 80% of total CSF MBL concentration 3) The smaller inter-individual variation of MBL concentrations in CSF of the control group (CV = 66%) compared to the MBL concentrations in serum (CV = 146%) indicate an independent source of MBL in CSF. 4) The absolute MBL concentration in CSF increases with increasing QAlb. Among brain-derived proteins in CSF only the leptomeningeal proteins showed a (linear) increase with decreasing CSF flow rate, neuronal and glial proteins are invariant to changes of QAlb. CONCLUSIONS MBL in CSF is predominantly brain-derived and all results pointed to the leptomeningeal cells as the source of the protein. The evaluation of this protein requires the interpretation of its absolute concentrations in CSF as a function of the albumin quotient, QAlb. This recognition of MBL in brain cells opens a new field of discussion about the function of the innate immune response in CNS in cases of acute and chronic neurological diseases.
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Affiliation(s)
- Hansotto Reiber
- Neurochemistry Laboratory, University Göttingen, Göttingen, Germany.
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Foldager L, Steffensen R, Thiel S, Als TD, Nielsen HJ, Nordentoft M, Mortensen PB, Mors O, Jensenius JC. MBL and MASP-2 concentrations in serum and MBL2 promoter polymorphisms are associated to schizophrenia. Acta Neuropsychiatr 2012; 24:199-207. [PMID: 25286812 DOI: 10.1111/j.1601-5215.2011.00618.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Objective:Causative relations between infections and psychosis, especially schizophrenia, have been speculated for more than a century, suggesting a hypothesis of association between schizophrenia and hereditary immune defects. Mannan-binding lectin (MBL) is a pattern-recognition molecule of the innate immune defence. MBL deficiency is the most common hereditary defect in the immune system and may predispose to infection and autoimmunity. Mannan-binding lectin serine protease-2 (MASP-2) is an MBL-associated serine protease mediating complement activation upon binding of MBL/MASP to microorganisms. The objective was to investigate if schizophrenia is associated with serum concentrations of MBL and MASP-2 or with genetic variants of the genesMBL2andMASP2encoding these proteins.Methods:The sample consisted of 100 patients with schizophrenia and 350 controls. Concentrations of MBL and MASP-2 in serum were measured and seven single nucleotide polymorphisms known to influence these concentrations were genotyped.Results:Significant association of disease with genetic markers was found inMBL2but not inMASP2. Significant difference in MBL serum concentration was found between patients and controls when adjusting forMBL2haplotypes. For concentrations of MASP-2, a significant interaction effect between aMASP2variant and disease was found. Interestingly, MASP-2 levels also depended significantly on variants inMBL2exon 1.Conclusion:This study supports previous studies showing increased complement activity in patients with schizophrenia, indicates aetiological heterogeneity among patients and underlines that multilocus genotypes have to be considered when investigating effects on MBL level. It appears that inclusion of additional components from the system of complement activation is warranted.
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Affiliation(s)
- Leslie Foldager
- Centre for Psychiatric Research, Aarhus University Hospital, Risskov, Denmark
| | - Rudi Steffensen
- Department of Clinical Immunology, Aalborg University Hospital, Aalborg, Denmark
| | - Steffen Thiel
- Institute of Medical Microbiology and Immunology, Aarhus University, Aarhus, Denmark
| | - Thomas Damm Als
- Centre for Psychiatric Research, Aarhus University Hospital, Risskov, Denmark
| | - Hans Jørgen Nielsen
- Department of Surgical Gastroenterology 435, Hvidovre University Hospital, Hvidovre, Denmark
| | - Merete Nordentoft
- Psychiatric Centre Copenhagen, University of Copenhagen, Copenhagen, Denmark
| | - Preben Bo Mortensen
- National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark
| | - Ole Mors
- Centre for Psychiatric Research, Aarhus University Hospital, Risskov, Denmark
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Damiens S, Poissy J, François N, Salleron J, Jawhara S, Jouault T, Poulain D, Sendid B. Mannose-binding lectin levels and variation during invasive candidiasis. J Clin Immunol 2012; 32:1317-23. [PMID: 22833166 DOI: 10.1007/s10875-012-9748-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 07/17/2012] [Indexed: 10/28/2022]
Abstract
The high morbi-mortality associated with invasive candidiasis (IC) is a persistent problem in hospitals. Mannose-binding lectin (MBL) plays a role in innate immunity through its interaction with mannosylated molecules of Candida albicans. A correlation between MBL deficiency and vulvovaginal candidiasis or peritonitis has been reported. We investigated circulating MBL levels and their evolution during the course of IC. Sixty-eight patients with proven IC, 82 hospitalized patients (HP) without evidence of infection, and 70 healthy subjects (HS) were studied in order to examine the relationship between serum MBL and IC. Serum MBL levels were measured by enzyme-linked immunosorbent assay (ELISA). MBL levels were significantly higher in IC patients than in HP and HS (p < 0.0001, p < 0.0055, respectively). A change in MBL concentrations was observed during the course of IC, with a dramatic decrease during the 2 days before positive blood culture sampling. This decrease was concomitant with the presence of high levels of circulating mannan (Mn). Like MBL levels, anti-mannan antibodies (AMn) increased after the mannanemia/blood culture period. These findings suggest a possible role of MBL during the early stage of IC. The mechanisms that regulate these observations in terms of effect and consequences on innate and adaptive immunity and the prognosis of IC require further investigation.
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The investigation of allele and genotype frequencies of human C3 (rs2230199) in south Iranian population. Mol Biol Rep 2012; 39:8919-24. [DOI: 10.1007/s11033-012-1759-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 06/07/2012] [Indexed: 10/28/2022]
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Tao R, Hua CZ, Hu YZ, Shang SQ. Genetic polymorphisms and serum levels of mannose-binding lectin in Chinese pediatric patients with common infectious diseases. Int J Infect Dis 2012; 16:e403-7. [DOI: 10.1016/j.ijid.2012.01.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 10/11/2011] [Accepted: 01/30/2012] [Indexed: 11/30/2022] Open
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Ferdinands JM, Denison AM, Dowling NF, Jost HA, Gwinn ML, Liu L, Zaki SR, Shay DK. A pilot study of host genetic variants associated with influenza-associated deaths among children and young adults. Emerg Infect Dis 2012; 17:2294-302. [PMID: 22172537 PMCID: PMC3311214 DOI: 10.3201/eid1712.111002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Low-producing MBL2 genotypes may have increased risk for MRSA co-infection. We compared the prevalence of 8 polymorphisms in the tumor necrosis factor and mannose-binding lectin genes among 105 children and young adults with fatal influenza with US population estimates and determined in subanalyses whether these polymorphisms were associated with sudden death and bacterial co-infection among persons with fatal influenza. No differences were observed in genotype prevalence or minor allele frequencies between persons with fatal influenza and the reference sample. Fatal cases with low-producing MBL2 genotypes had a 7-fold increased risk for invasive methicillin-resistant Staphylococcus aureus (MRSA) co-infection compared with fatal cases with high- and intermediate-producing MBL2 genotypes (odds ratio 7.1, 95% confidence interval 1.6–32.1). Limited analysis of 2 genes important to the innate immune response found no association between genetic variants and fatal influenza infection. Among children and young adults who died of influenza, low-producing MBL2 genotypes may have increased risk for MRSA co-infection.
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67
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Strack C, Baessler A, Wagner F, Bruxmeier J, Yaroslavskii O, Rousseva E, Loew T, Riegger G, Schmitz G, Fischer M. Mannose-binding lectin in obesity with different degrees of metabolic syndrome abnormalities: association with atherogenic and metabolic traits. J Atheroscler Thromb 2012; 19:539-51. [PMID: 22472212 DOI: 10.5551/jat.10918] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIM In subjects with metabolic syndrome (MetS) endothelial dysfunction is a very consistent finding. Processes leading to endothelial dysfunction and atherosclerosis involve the altered control of subclinical inflammation by innate immune defenses that possibly include mannose-binding lectin (MBL). We investigated the associations of MBL with traits of MetS and early atherosclerosis in obese subjects before and after marked weight reduction. METHODS In a prospective longitudinal study, MBL concentrations of 96 severely obese subjects with and without MetS (Ø BMI with MetS 41.0±7.9 kg/m(2), Ø BMI without MetS 39.4±7.7 kg/m(2) were examined in association with markers of insulin resistance, dyslipidemia, adipokines, and subclinical atherosclerosis before and after marked weight loss (Ø weight loss 20±8 kg after 3 months of participation in a standardized weight reduction program), in addition to the study of 25 seemingly healthy lean subjects (BMI 20-25 kg/m(2). RESULTS MBL concentrations did not differ between healthy lean and severely obese subjects independently of the presence of metabolic abnormalities. In severely obese subjects there was no significant difference concerning the cardiovascular risk profile, apolipoproteins, inflammatory and metabolic parameters, and markers of endothelial dysfunction and atherosclerosis between subjects with functional MBL deficienct (MBL<778 ng/mL) and MBL sufficient (MBL≥778 ng/mL) obesity. Marked weight loss did not influence MBL levels. CONCLUSIONS Our findings suggest that plasma levels of MBL did not differ between healthy lean and severely obese subjects. MBL did not affect cardiovascular risk factors, or markers of endothelial dysfunction and early atherosclerosis in severely obese patients before and after marked weight loss.
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Affiliation(s)
- Christina Strack
- Clinic for Internal Medicine II, University Medical Centre, Regensburg, Germany
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68
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Serum Mannan-Binding Lectin in Egyptian Patients With Chronic Hepatitis C: Its Relation to Disease Progression and Response to Treatment. HEPATITIS MONTHLY 2012. [DOI: 10.5812/hepatmon.5861] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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69
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Salvatori G, Campo S. Current understanding of PTX3 protective activity onAspergillus fumigatusinfection. Med Mycol 2012; 50:225-33. [DOI: 10.3109/13693786.2011.648215] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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70
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Esmat S, Omran D, Sleem GA, Rashed L. Serum mannan-binding lectin in egyptian patients with chronic hepatitis C: its relation to disease progression and response to treatment. HEPATITIS MONTHLY 2012; 12:259-64. [PMID: 22690233 PMCID: PMC3360935 DOI: 10.5812/hepatmon.704] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 04/30/2011] [Accepted: 05/10/2011] [Indexed: 12/11/2022]
Abstract
BACKGROUND Chronic hepatitis C virus (HCV) infection is a major worldwide public health problem. Egypt has the highest prevalence of adult HCV infection in the world, averaging 15%-25% in rural communities. Mannan-binding lectin (MBL) is a liver-derived pluripotent serum lectin that plays a role in the innate immune system of the host. It is an acute-phase protein that is involved in the activation of the classical complement pathway. MBL may play a defensive role in HCV infection. OBJECTIVES To investigate the relationship between MBL concentration and HCV infection in Egyptian patients suffering chronic hepatitis C. PATIENTS AND METHODS Serum samples obtained from 35 Egyptian hepatitis C patients and 30 normal controls were assayed for MBL. MBL concentrations were correlated to disease characteristics and treatment response. RESULTS Serum MBL was significantly higher in HCV patients than in controls, but no relationship was found between MBL concentration and disease progression in terms of hepatic fibrosis and inflammation. Responders to interferon (INF)-based therapy had significantly higher serum MBL than non-responders. CONCLUSIONS We found no association between serum MBL concentration and progression of HCV related liver disease. Responders to INF-based therapy had significantly higher serum MBL than non-responders.
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Affiliation(s)
- Serag Esmat
- Department of Internal Medicine, Faculty of Medicine, Cairo University, Cairo, Egypt
- Corresponding author: Serag Esmat, Department of Internal Medicine, Faculty of Medicine, Cairo University, 18, Elamin, St. Mohandissin, Cairo, Egypt. Tel.: +20-233026158, Fax: +20-122190974, E-mail:
| | - Dalia Omran
- Department of Tropical Medicine, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Gihan A. Sleem
- Department of Internal Medicine, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Laila Rashed
- Department of Biochemistry, Faculty of Medicine, Cairo University, Cairo, Egypt
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71
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Weitzel T, Zulantay I, Danquah I, Hamann L, Schumann RR, Apt W, Mockenhaupt FP. Mannose-binding lectin and Toll-like receptor polymorphisms and Chagas disease in Chile. Am J Trop Med Hyg 2012; 86:229-32. [PMID: 22302853 DOI: 10.4269/ajtmh.2012.11-0539] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
Mannose-binding lectin (MBL) and Toll-like receptor (TLR) polymorphisms may influence susceptibility and manifestation of Trypanosoma cruzi infection. In northern Chile, we examined 61 asymptomatic patients with chronic Chagas disease (CD), 64 patients with chronic Chagas cardiomyopathy (CCC), and 45 healthy individuals. Low-producer MBL2*B genotypes were more common in CD patients (48%) than healthy individuals (31%; adjusted odds ratio = 2.3, 95% confidence interval = 1.01-5.4, P = 0.047) but did not differ with manifestation. In contrast, the heterozygous Toll-like receptor 4 (TLR4)-deficiency genotype D299G/T399I occurred more frequently in asymptomatic (14.8%) than CCC patients (3.1%; P = 0.02). TLR1-I602S, TLR2-R753Q, TLR6-S249P, and MAL/TIRAP-S180L did not associate with CD or CCC. These findings support the complement system to be involved in defense against Trypanosoma cruzi infection and indicate that curbed TLR4 activation might be beneficial in preventing CCC.
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Affiliation(s)
- Thomas Weitzel
- Laboratorio Clinico, Clinica Alemana/Universidad de Desarrollo, Santiago, Chile.
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72
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MBL Deficiency as Risk of Infection and Autoimmunity. ANIMAL LECTINS: FORM, FUNCTION AND CLINICAL APPLICATIONS 2012:933-953. [PMCID: PMC7122001 DOI: 10.1007/978-3-7091-1065-2_42] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/30/2023]
Abstract
In pathogen recognition by C-type lectins, several levels of complexity can be distinguished; these might modulate the immune response in different ways. Firstly, the pathogen-associated molecular pattern repertoire expressed at the microbial surface determines the interactions with specific receptors (Fig. 42.1). Secondly, each immune cell type possesses a specific set of pathogen-recognition receptors. Thirdly, changes in the cell-surface distribution of C-type lectins regulate carbohydrate binding by modulating receptor affinity for different ligands. Crosstalk between these receptors results in a network of multimolecular complexes, adding a further level of complexity in pathogen recognition (Cambi and Figdor 2005; Thiel et al. 2006) (see 10.1007/978-3-7091-1065-2_23). MBL deficiency is genetically determined and predisposes to recurrent infections and chronic inflammatory diseases. MBL deficiency has been implicated in susceptibility and course of viral, bacterial, fungal, and protozoan infection. More than 10% of the general population may, depending on definition, be classified as MBL deficient, underlining the redundancy of the immune system. MBL-disease association studies have been a fruitful area of research, which implicates a role for MBL in infective, inflammatory and autoimmune disease processes. MBL deficiency predisposes both to infection by extra-cellular pathogens and to autoimmune disease.
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73
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Kainulainen L, Peltola V, Seppänen M, Viander M, He Q, Lokki ML, Ruuskanen O. C4A deficiency in children and adolescents with recurrent respiratory infections. Hum Immunol 2012; 73:498-501. [PMID: 22406254 DOI: 10.1016/j.humimm.2012.02.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 02/19/2012] [Accepted: 02/22/2012] [Indexed: 12/22/2022]
Abstract
Increased susceptibility to recurrent viral and bacterial respiratory infections in children and young adults is not well understood. To evaluate the role of complement factor C4 in the defense against respiratory infections, we studied complement factor C4 allotypes C4A and C4B and copy numbers of C4A and C4B genes in 84 children and young adults with recurrent acute otitis media, sinusitis, or pneumonia and in 74 healthy controls. The occurrence of C4A gene deficiency was significantly higher in patients compared with controls (26% vs 14%, p = 0.048). Girls predominated in the group of patients with C4A deficiency (73% girls and 27% boys, p = 0.004). The lectin pathway of complement was more often functionally impaired in patients with C4A deficiency than in patients with no C4A deficiency (41% vs 13%, p = 0.033). Classical and alternative pathways were normal in individuals with C4 null alleles. C4A deficiency is 1 of the minor defects of the innate immunity that may predispose children and young adults to recurrent respiratory infections. C4 gene testing should be added to the list of investigations when the cause for recurrent acute otitis media, maxillary sinusitis, or pneumonia in children and young adults is sought.
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Affiliation(s)
- Leena Kainulainen
- Department of Pediatrics, Turku University Hospital, Turku, Finland.
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74
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Pradhan V, Gorakshakar A. Are mannose-binding lectin gene 2 (MBL2) polymorphisms and MBL deficiency associated with infections? INDIAN JOURNAL OF HUMAN GENETICS 2011; 17:45-7. [PMID: 22090711 PMCID: PMC3214316 DOI: 10.4103/0971-6866.86170] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Vandana Pradhan
- National Institute of Immunohaematology (ICMR), KEM Hospital Campus, Parel, Mumbai, India
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75
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Demirhan O, Taştemir D, Güneşaçar R, Güzel Aİ, Alptekin D. The first report described as an important study: The association of mannose-binding lectin gene 2 polymorphisms in children with Down syndrome. INDIAN JOURNAL OF HUMAN GENETICS 2011; 17:59-64. [PMID: 22090714 PMCID: PMC3214319 DOI: 10.4103/0971-6866.86176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
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.
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Affiliation(s)
- Osman Demirhan
- Department of Medical Biology and Genetics, Çukurova University, Adana, Turkey
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76
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Ferraroni NR, Segat L, Guimarães RL, Brandão LAC, Crovella S, Constantino-Silva RN, Loja C, da Silva Duarte AJ, Grumach AS. Mannose-binding lectin and MBL-associated serine protease-2 gene polymorphisms in a Brazilian population from Rio de Janeiro. Int J Immunogenet 2011; 39:32-8. [DOI: 10.1111/j.1744-313x.2011.01052.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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77
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Ishii M, Ohsawa I, Inoshita H, Kusaba G, Onda K, Wakabayashi M, Ohi H, Horikoshi S, Matsushita M, Tomino Y. Serum concentration of complement components of the lectin pathway in maintenance hemodialysis patients, and relatively higher levels of L-Ficolin and MASP-2 in Mannose-binding lectin deficiency. Ther Apher Dial 2011; 15:441-7. [PMID: 21974696 DOI: 10.1111/j.1744-9987.2011.00936.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mannose-binding lectin (MBL), L-ficolin and MBL associated serine protease-2 (MASP-2) are molecules involved in initiation of the lectin pathway (LP) in the complement system. Although MBL deficiency is observed in almost 10% of healthy people, studies of associations between MBL deficiency and end-stage renal disease (ESRD) remain rare. The objective of the present study is to clarify the significance of the LP in maintenance hemodialysis (HD) patients, especially in terms of MBL levels. Two hundred and forty-four HD patients who had been followed up for 74±84months and 199 healthy controls were included in this study. Measurements of serum concentrations of MBL, L-ficolin, and MASP-2 were performed. Low serum MBL levels (<0.1µg/mL) in the patients were confirmed by examination of a point mutation in the Mbl-2 gene. Seventeen HD patients (7%) and 20 healthy controls (10%) had MBL deficiency. During the follow-up period, 99 patients died. There was no significant difference in the frequency of deaths by infectious diseases between MBL deficient and non-deficient patients. In both patients and healthy controls with MBL deficiency, the serum concentration of L-ficolin tended to be high, and that of MASP-2 was significantly high (P<0.05). MBL deficiency is not a risk factor for HD induction or life-threatening infections. It is postulated that the elevation of concentration of the two components of the LP, L-ficolin and MASP-2, may compensate for the insufficient activity of the LP in MBL deficiency.
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Affiliation(s)
- Masaya Ishii
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo Department of Applied Biochemistry, Tokai University, Kanagawa, Japan
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78
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Carroll MV, Sim RB. Complement in health and disease. Adv Drug Deliv Rev 2011; 63:965-75. [PMID: 21704094 DOI: 10.1016/j.addr.2011.06.005] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 06/06/2011] [Accepted: 06/09/2011] [Indexed: 12/16/2022]
Abstract
The complement system consists of about 35-40 proteins and glycoproteins present in blood plasma or on cell surfaces. Its main biological function is to recognise "foreign" particles and macromolecules, and to promote their elimination either by opsonisation or lysis. Although historically complement has been studied as a system for immune defence against bacteria, it has an important homeostatic role in which it recognises damaged or altered "self" components. Thus complement has major roles in both immune defence against microorganisms, and in clearance of damaged or "used" host components. Since complement proteins opsonise or lyse cells, complement can damage healthy host cells and tissues. The system is regulated by many endogenous regulatory proteins. Regulation is sometimes imperfect and both too much and too little complement activation is associated with many diseases. Excessive or inappropriate activation can cause tissue damage in diseases such as rheumatoid arthritis, age-related macular degeneration (AMD), multiple sclerosis, ischemia-reperfusion injury (e.g. ischemic stroke). Insufficient complement activity is associated with susceptibility to infection (mainly bacterial) and development of autoimmune disease, like SLE (systemic lupus erythematosus).
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79
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The significance of mannose-binding lectin gene polymorphisms on the risk of BK virus coinfection in women with human papillomavirus–positive cervical lesions. Hum Immunol 2011; 72:663-6. [DOI: 10.1016/j.humimm.2011.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/19/2011] [Accepted: 04/08/2011] [Indexed: 11/16/2022]
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80
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Ermini L, Wilson IJ, Goodship THJ, Sheerin NS. Complement polymorphisms: geographical distribution and relevance to disease. Immunobiology 2011; 217:265-71. [PMID: 21899915 DOI: 10.1016/j.imbio.2011.07.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2011] [Revised: 06/20/2011] [Accepted: 07/18/2011] [Indexed: 10/17/2022]
Abstract
The evolution of man has been characterised by recurrent episodes of migration and settlement with infectious disease a constant threat. This long history of demographic change, together with the action of evolutionary forces such as natural selection and genetic drift, has shaped human genetic diversity. In particular, the interaction between humans, pathogens and the environment has played a crucial role in generating patterns of human genetic variation. The complement system plays a crucial role in the early protective immune response after exposure to a pathogen. Pathogens, over time, have developed mechanisms to circumvent the effects of complement which in turn has led to development of a more complex complement system. During the evolution of the complement system genes coding complement proteins have evolved polymorphisms, some of which have a functional effect, and this may reflect human-pathogen interaction and geographical origin. An example is the polymorphism Ile62Val (rs800292 (A>G)) in the complement regulator Factor H gene which alters the susceptibility to age-related macular degeneration (AMD), with the Ile62 polymorphism protecting against AMD. When sub-Saharan African and European populations are compared, the frequency of this polymorphism shows a very marked geographical distribution. Polymorphisms in other complement genes such as complement factor B show similar trends. This paper describes the geographical variation present in complement genes and discusses the implications of these observations. The analysis of genetic variation in complement genes is a promising tool to unravel mechanisms of host-pathogen interaction and can provide new insights into the evolution of the human immune system.
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Affiliation(s)
- L Ermini
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
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81
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Resman F, Svensjö T, Ünal C, Cronqvist J, Brorson H, Odenholt I, Riesbeck K. Necrotizing myositis and septic shock caused by Haemophilus influenzae type f in a previously healthy man diagnosed with an IgG3 and a mannose-binding lectin deficiency. ACTA ACUST UNITED AC 2011; 43:972-6. [PMID: 21728743 DOI: 10.3109/00365548.2011.589079] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
An increased incidence of infections by Haemophilus influenzae type f (Hif) has recently been suggested, but such infections have mainly been regarded as opportunistic. We present here a dramatic case of Hif necrotizing myositis and septic shock. A subsequently diagnosed IgG3 and mannose-binding lectin deficiency possibly contributed to the severe outcome.
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Affiliation(s)
- Fredrik Resman
- Medical Microbiology, Department of Laboratory Medicine Malmö, Lund University, Skåne University Hospital, SE-20502 Malmö, Sweden.
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82
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Degn S, Jensenius J, Thiel S. Disease-causing mutations in genes of the complement system. Am J Hum Genet 2011; 88:689-705. [PMID: 21664996 DOI: 10.1016/j.ajhg.2011.05.011] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 04/19/2011] [Accepted: 05/08/2011] [Indexed: 02/08/2023] Open
Abstract
Recent studies have revealed profound developmental consequences of mutations in genes encoding proteins of the lectin pathway of complement activation, a central component of the innate immune system. Apart from impairment of immunity against microorganisms, it is known that hereditary deficiencies of this system predispose one to autoimmune conditions. Polymorphisms in complement genes are linked to, for example, atypical hemolytic uremia and age-dependent macular degeneration. The complement system comprises three convergent pathways of activation: the classical, the alternative, and the lectin pathway. The recently discovered lectin pathway is less studied, but polymorphisms in the plasma pattern-recognition molecule mannan-binding lectin (MBL) are known to impact its level, and polymorphisms in the MBL-associated serine protease-2 (MASP-2) result in defects of complement activation. Recent studies have described roles outside complement and immunity of another MBL-associated serine protease, MASP-3, in the etiology of 3MC syndrome, an autosomal-recessive disorder involving a spectrum of developmental features, including characteristic facial dysmorphism. Syndrome-causing mutations were identified in MASP1, encoding MASP-3 and two additional proteins, MASP-1 and MAp44. Furthermore, an association was discovered between 3MC syndrome and mutations in COLEC11, encoding CL-K1, another molecule of the lectin pathway. The findings were confirmed in zebrafish, indicating that MASP-3 and CL-K1 underlie an evolutionarily conserved pathway of embryonic development. Along with the discovery of a role of C1q in pruning synapses in mice, these recent advances point toward a broader role of complement in development. Here, we compare the functional immunologic consequences of "conventional" complement deficiencies with these newly described developmental roles.
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83
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Clemons KV, Martinez M, Axelsen M, Thiel S, Stevens DA. Efficacy of Recombinant Human Mannose Binding Lectin Alone and in Combination with Itraconazole Against MurineCandida albicansvaginitis. Immunol Invest 2011; 40:553-68. [DOI: 10.3109/08820139.2011.569627] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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84
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Sanders MS, van Well GTJ, Ouburg S, Morré SA, van Furth AM. Genetic variation of innate immune response genes in invasive pneumococcal and meningococcal disease applied to the pathogenesis of meningitis. Genes Immun 2011; 12:321-34. [DOI: 10.1038/gene.2011.20] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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85
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Sheng A, Lan J, Wu H, Lu J, Wang Y, Chu Q, Jia Z, Song M, Liu L, Wang W. A clinical case-control study on the association between mannose-binding lectin and susceptibility to HIV-1 infection among northern Han Chinese population. Int J Immunogenet 2011; 37:445-54. [PMID: 20618520 DOI: 10.1111/j.1744-313x.2010.00946.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mannose-binding lectin (MBL) is a key molecule of the innate immune system and a competent to bind carbohydrates of a variety of microorganisms, resulting in complement activation and opsonophagocytosis against various pathogens. However, there is no systemic investigation on the MBL's role in innate immune responses against HIV-1 infection among northern Han Chinese. This study investigated the association between MBL and HIV-1 infection susceptibility among northern Han Chinese. A total of 91 HIV-1 infected patients and 91 HIV-1 seronegative healthy individuals were recruited. Six polymorphisms of MBL2 gene were genotyped by pyrosequencing. The quantitative measurement of serum MBL concentration and MBL complex activity were performed by ELISA. The CD4+ T-cell counts were determined by flow cytometry. The plasma viral loads of 91 HIV-1 infected patients were determined by bDNA method. The results show that there is an association between MBL and HIV-1 infection susceptibility among northern Han Chinese. The individuals with B variant, low serum MBL concentration and low MBL complex activity are more susceptible to HIV-1 infection.
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Affiliation(s)
- A Sheng
- School of Public Health and Family Medicine, Capital Medical University, Beijing, China
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86
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Fuchs A, Pinto AK, Schwaeble WJ, Diamond MS. The lectin pathway of complement activation contributes to protection from West Nile virus infection. Virology 2011; 412:101-9. [PMID: 21269656 DOI: 10.1016/j.virol.2011.01.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 11/24/2010] [Accepted: 01/04/2011] [Indexed: 11/27/2022]
Abstract
The function of the lectin pathway of complement activation in vivo against West Nile virus (WNV) or many other pathogenic viruses has not been defined. Mice deficient in lectin pathway recognition molecules (mannose binding lectin-A (MBL-A) and mannose binding lectin-C (MBL-C)) or the effector enzyme mannan-binding lectin-associated serine protease-2 (MASP-2), were more vulnerable to WNV infection than wild type mice. Compared with studies of mice deficient in factors of the classical or alternative pathway, MBL-A(-/-) × MBL-C(-/-) or MASP-2(-/-) mice showed a less severe course of WNV infection. Indeed, a deficiency in lectin pathway activation did not significantly affect the kinetics of viral spread to the central nervous system (CNS) nor did it profoundly alter generation of adaptive B and T cell immune responses. We conclude that MBL-mediated recognition and lectin pathway activation have important yet subordinate functions in protecting against WNV infection and disease.
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Affiliation(s)
- Anja Fuchs
- Department of Medicine, Washington University School of Medicine, 660 South Euclid Ave., St. Louis, MO 63110, USA
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87
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Infections of people with complement deficiencies and patients who have undergone splenectomy. Clin Microbiol Rev 2010; 23:740-80. [PMID: 20930072 DOI: 10.1128/cmr.00048-09] [Citation(s) in RCA: 254] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The complement system comprises several fluid-phase and membrane-associated proteins. Under physiological conditions, activation of the fluid-phase components of complement is maintained under tight control and complement activation occurs primarily on surfaces recognized as "nonself" in an attempt to minimize damage to bystander host cells. Membrane complement components act to limit complement activation on host cells or to facilitate uptake of antigens or microbes "tagged" with complement fragments. While this review focuses on the role of complement in infectious diseases, work over the past couple of decades has defined several important functions of complement distinct from that of combating infections. Activation of complement in the fluid phase can occur through the classical, lectin, or alternative pathway. Deficiencies of components of the classical pathway lead to the development of autoimmune disorders and predispose individuals to recurrent respiratory infections and infections caused by encapsulated organisms, including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. While no individual with complete mannan-binding lectin (MBL) deficiency has been identified, low MBL levels have been linked to predisposition to, or severity of, several diseases. It appears that MBL may play an important role in children, who have a relatively immature adaptive immune response. C3 is the point at which all complement pathways converge, and complete deficiency of C3 invariably leads to severe infections, including those caused by meningococci and pneumococci. Deficiencies of the alternative and terminal complement pathways result in an almost exclusive predisposition to invasive meningococcal disease. The spleen plays an important role in antigen processing and the production of antibodies. Splenic macrophages are critical in clearing opsonized encapsulated bacteria (such as pneumococci, meningococci, and Escherichia coli) and intraerythrocytic parasites such as those causing malaria and babesiosis, which explains the fulminant nature of these infections in persons with anatomic or functional asplenia. Paramount to the management of patients with complement deficiencies and asplenia is educating patients about their predisposition to infection and the importance of preventive immunizations and seeking prompt medical attention.
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88
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Fuchs A, Lin TY, Beasley DW, Stover CM, Schwaeble WJ, Pierson TC, Diamond MS. Direct complement restriction of flavivirus infection requires glycan recognition by mannose-binding lectin. Cell Host Microbe 2010; 8:186-95. [PMID: 20709295 DOI: 10.1016/j.chom.2010.07.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 05/11/2010] [Accepted: 06/07/2010] [Indexed: 01/08/2023]
Abstract
An intact complement system is crucial for limiting West Nile virus (WNV) dissemination. Herein, we define how complement directly restricts flavivirus infection in an antibody-independent fashion. Mannose-binding lectin (MBL) recognized N-linked glycans on the structural proteins of WNV and Dengue virus (DENV), resulting in neutralization through a C3- and C4-dependent mechanism that utilized both the canonical and bypass lectin activation pathways. For WNV, neutralization occurred with virus produced in insect cells, whereas for DENV, neutralization of insect and mammalian cell-derived virus was observed. Mechanism of action studies suggested that the MBL-dependent neutralization occurred, in part, by blocking viral fusion. Experiments in mice showed an MBL-dependent accelerated intravascular clearance of DENV or a WNV mutant with two N-linked glycans on its E protein, but not with wild-type WNV. Our studies show that MBL recognizes terminal mannose-containing carbohydrates on flaviviruses, resulting in neutralization and efficient clearance in vivo.
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Affiliation(s)
- Anja Fuchs
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
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89
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Lotz DR, Knutsen AP. Concomitant Selective Antibody Deficiency in Pediatric Patients with Mannose-Binding Lectin Deficiency. PEDIATRIC ALLERGY IMMUNOLOGY AND PULMONOLOGY 2010. [DOI: 10.1089/ped.2010.0035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Douglas R. Lotz
- Division of Allergy and Immunology, Department of Pediatrics, Saint Louis University, St. Louis, Missouri
| | - Alan P. Knutsen
- Division of Allergy and Immunology, Department of Pediatrics, Saint Louis University, St. Louis, Missouri
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90
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Mellbin LG, Hamsten A, Malmberg K, Steffensen R, Rydén L, Ohrvik J, Hansen TK. Mannose-binding lectin genotype and phenotype in patients with type 2 diabetes and myocardial infarction: a report from the DIGAMI 2 trial. Diabetes Care 2010; 33:2451-6. [PMID: 20693349 PMCID: PMC2963511 DOI: 10.2337/dc10-0903] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The present study characterizes mannose-binding lectin (MBL), an activator of the complement system and thereby important for inflammatory activation, in patients with diabetes and myocardial infarction. RESEARCH DESIGN AND METHODS Serum (S)-MBL was determined at hospital admission in 387 patients with type 2 diabetes (median age 70 years; 68% male) with myocardial infarction, and genotyping was performed in 287 patients. Cardiovascular events (cardiovascular mortality and nonfatal myocardial infarction or stroke) were recorded during 2.5 years. RESULTS Median S-MBL was 1,212 μg/l (interquartile range [IQR] 346-2,681 μg/l). Of the subjects, 54% in the geno- and phenotype subgroup had a high-coding MBL genotype (median S-MBL=2,658 μg/l [IQR 1,715-3,829]) and 46% a low-coding MBL genotype (373 μg/l [100-765]). S-MBL did not correlate with age, BMI, creatinine clearance, glucose, or A1C. Cardiovascular events occurred in 136 (35%) patients. S-MBL did not predict events in univariable analyses (hazard ratio 0.93 [95% CI 0.85-1.01]; P=0.09). In unadjusted analyses, the risk of events was lower in patients with a high genotype and S-MBL above the median for their genotype (0.49 [0.26-0.92]; P=0.026) than for patients with a low genotype and S-MBL below the median for their genotype. The prediction capacity of the geno- and phenotype model was of borderline significance in adjusted Cox regression. CONCLUSIONS Patients with type 2 diabetes and myocardial infarction have MBL genotypes that are similar to those known in the general population. The combination of a low-coding MBL genotype with a low S-MBL appears to be prognostically unfavorable, but the association is blunted by traditional risk markers.
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Affiliation(s)
- L G Mellbin
- Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
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91
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Bulla R, De Seta F, Radillo O, Agostinis C, Durigutto P, Pellis V, De Santo D, Crovella S, Tedesco F. Mannose-binding lectin is produced by vaginal epithelial cells and its level in the vaginal fluid is influenced by progesterone. Mol Immunol 2010; 48:281-6. [PMID: 20728220 DOI: 10.1016/j.molimm.2010.07.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 07/20/2010] [Accepted: 07/25/2010] [Indexed: 11/30/2022]
Abstract
Mannose-binding lectin (MBL) is a recognition molecule of the complement (C) system and binds to carbohydrate ligands present on a wide range of pathogenic bacteria, viruses, fungi, and parasites. MBL has been detected in the cervico-vaginal cavity where it can provide a first-line defence against infectious agents colonizing the lower tract of the reproductive system. Analysis of the cervico-vaginal lavage (CVL) obtained from 11 normal cycling women at different phases of the menstrual cycle revealed increased levels of MBL in the secretive phase. Part of this MBL derives from the circulation as indicated by the presence of transferrin in CVL tested as a marker of vascular and tissue permeability. The local synthesis of MBL is suggested by the finding that its level is substantially higher than that of transferrin in the secretive phase. The contribution of endometrium is negligible since the MBL level did not change before and after hysterectomy. RT-PCR and in situ RT-PCR analysis showed that the vaginal tissue, and in particular the basal layer of the epithelium, is a source of MBL which binds to the basal membrane and to cells of the outer layers of the epithelium. In conclusion, we have shown that MBL detected in CVL derives both from plasma as result of transudation and from local synthesis and its level is progesterone dependent increasing in the secretive phase of the menstrual cycle.
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Affiliation(s)
- R Bulla
- Department of Life Sciences, University of Trieste, via Valerio 28, 34127 Trieste, Italy
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92
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Host genetics and outcome in meningococcal disease: a systematic review and meta-analysis. THE LANCET. INFECTIOUS DISEASES 2010; 10:262-74. [DOI: 10.1016/s1473-3099(10)70045-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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93
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Potlukova E, Jiskra J, Freiberger T, Limanova Z, Zivorova D, Malickova K, Springer D, Grodecka L, Antosova M, Telicka Z, Pesickova SS, Trendelenburg M. The production of mannan-binding lectin is dependent upon thyroid hormones regardless of the genotype: a cohort study of 95 patients with autoimmune thyroid disorders. Clin Immunol 2010; 136:123-9. [PMID: 20356797 DOI: 10.1016/j.clim.2010.02.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 02/21/2010] [Accepted: 02/24/2010] [Indexed: 11/16/2022]
Abstract
Complement mannan-binding lectin (MBL) deficiency is associated with increased susceptibility to infections and autoimmune diseases. Previous studies suggested that the production of MBL is stimulated by thyroid hormones. The aim of our study was to investigate this association in patients with autoimmune thyroid diseases (AITD). Serum levels of MBL and parameters of the thyroid function were determined in 62 patients with Hashimoto's thyroiditis, 33 with Graves' disease and 47 blood donors. Follow-up measurements were performed after 6 to 24 months. MBL2 genotypes were determined using multiplex PCR and compared to 359 healthy Czech individuals. Serum levels of MBL tightly correlated with thyroid hormones, leading to strongly increased MBL levels in hyperthyroidism and decreased levels in hypothyroidism. With normalization of the thyroid function during follow-up, MBL levels decreased or increased respectively. The observed correlations were not due to MBL polymorphisms since the frequency of MBL2 polymorphisms in AITD patients was not different from the general population. We conclude that AITD are not associated with MBL polymorphisms. However, the MBL production is strongly dependent on thyroid function, regardless of the genotype.
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Affiliation(s)
- Eliska Potlukova
- Third Department of Medicine, General University Hospital and First Faculty of Medicine, Charles University in Prague, Czech Republic.
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94
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Cestari I, Ramirez MI. Inefficient complement system clearance of Trypanosoma cruzi metacyclic trypomastigotes enables resistant strains to invade eukaryotic cells. PLoS One 2010; 5:e9721. [PMID: 20300530 PMCID: PMC2838796 DOI: 10.1371/journal.pone.0009721] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Accepted: 02/23/2010] [Indexed: 11/19/2022] Open
Abstract
The complement system is the main arm of the vertebrate innate immune system against pathogen infection. For the protozoan Trypanosoma cruzi, the causative agent of Chagas disease, subverting the complement system and invading the host cells is crucial to succeed in infection. However, little attention has focused on whether the complement system can effectively control T. cruzi infection. To address this question, we decided to analyse: 1) which complement pathways are activated by T. cruzi using strains isolated from different hosts, 2) the capacity of these strains to resist the complement-mediated killing at nearly physiological conditions, and 3) whether the complement system could limit or control T. cruzi invasion of eukaryotic cells. The complement activating molecules C1q, C3, mannan-binding lectin and ficolins bound to all strains analysed; however, C3b and C4b deposition assays revealed that T. cruzi activates mainly the lectin and alternative complement pathways in non-immune human serum. Strikingly, we detected that metacyclic trypomastigotes of some T. cruzi strains were highly susceptible to complement-mediated killing in non-immune serum, while other strains were resistant. Furthermore, the rate of parasite invasion in eukaryotic cells was decreased by non-immune serum. Altogether, these results establish that the complement system recognizes T. cruzi metacyclic trypomastigotes, resulting in killing of susceptible strains. The complement system, therefore, acts as a physiological barrier which resistant strains have to evade for successful host infection.
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Affiliation(s)
- Igor Cestari
- Laboratório de Biologia Molecular de Parasitas e Vetores, Instituto Oswaldo Cruz - Fiocruz, Rio de Janeiro, Brazil
| | - Marcel I. Ramirez
- Laboratório de Biologia Molecular de Parasitas e Vetores, Instituto Oswaldo Cruz - Fiocruz, Rio de Janeiro, Brazil
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95
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Abstract
Much remains to be learned about the pathogenesis of the different manifestations of dengue virus (DENV) infections in humans. They may range from subclinical infection to dengue fever, dengue hemorrhagic fever (DHF), and eventually dengue shock syndrome (DSS). As both cell tropism and tissue tropism of DENV are considered major determinants in the pathogenesis of dengue, there is a critical need for adequate tropism assays, animal models, and human autopsy data. More than 50 years of research on dengue has resulted in a host of literature, which strongly suggests that the pathogenesis of DHF and DSS involves viral virulence factors and detrimental host responses, collectively resulting in abnormal hemostasis and increased vascular permeability. Differential targeting of specific vascular beds is likely to trigger the localized vascular hyperpermeability underlying DSS. A personalized approach to the study of pathogenesis will elucidate the basis of individual risk for development of DHF and DSS as well as identify the genetic and environmental bases for differences in risk for development of severe disease.
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96
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Trendelenburg M, Theroux P, Stebbins A, Granger C, Armstrong P, Pfisterer M. Influence of functional deficiency of complement mannose-binding lectin on outcome of patients with acute ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention. Eur Heart J 2010; 31:1181-7. [DOI: 10.1093/eurheartj/ehp597] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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97
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Nisihara RM, Utiyama SR, Oliveira NP, Messias-Reason IJ. Mannan-binding lectin deficiency increases the risk of recurrent infections in children with Down's syndrome. Hum Immunol 2010; 71:63-6. [DOI: 10.1016/j.humimm.2009.09.361] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 09/22/2009] [Accepted: 09/30/2009] [Indexed: 11/16/2022]
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98
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Abstract
Conglutinin represents a collectin appearing only in some mammals, including cattle. It plays an important role in resistance of hosts against microbes and parasites. It exhibits affinity toward saccharides present on the surface of bacteria, viruses, fungi and parasites and it mobilizes the mechanisms leading to their inactivation. It manifests also the unique ability of agglutinating complement- and antibody-coated erythrocytes. Moreover, it shows the ability to activate immune system cells, including the process of phagocytosis. In this review also the factors that determine the amount and activity of conglutinin in mammalian serum were presented, including environmental conditions and infectious agents, such as various types of bacteria and viruses. The broad scope of conglutinin is genetically controlled and, therefore, this collectin may constitute a useful and crucial factor in cattle husbandry.
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99
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Vallès X, Sarrias MR, Casals F, Farnós M, Piñer R, Suárez B, Morais L, Mandomando I, Sigaúque B, Roca A, Alonso PL, Torres A, Thielens NM, Lozano F. Genetic and structural analysis of MBL2 and MASP2 polymorphisms in south-eastern African children. ACTA ACUST UNITED AC 2009; 74:298-307. [PMID: 19775369 DOI: 10.1111/j.1399-0039.2009.01328.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mannose-binding lectin (MBL) pathway of complement system is activated when carbohydrate-bound MBL forms complexes with different serine proteases (MASP-1, MASP-2 and MASP-3), among which MASP-2 has a predominant functional role. Polymorphisms impairing the quantity and/or the functional activity of proteins encoded by the MBL2 and MASP2 genes have been reported in all human populations showing different allelic frequency and distribution. This likely reflects the existence of environmental influences on MBL2 and MASP2 genetic evolution. Herewith, we conducted a study in a children population from Mozambique to analyse the genetic diversity of sequences corresponding to the promoter and collagen-like region (exon 1) of MBL2 and to the CUB-1 and epidermal growth factor domain (exon 3) of MASP2, which are critical regions for the formation of functional MBL/MASP-2 complexes. Our results show a high prevalence of MBL-intermediate/low genotypes (43.5%); the description of new alleles and a high level of sequence polymorphism at both MBL2 and MASP2, with no statistical evidence for positive or balancing selection. Furthermore, Biacore analyses performed to explore the functional relevance of the MASP2 variants found [T73M (2.9%), R84Q (12.7%) and P111L (25.4%)] were compared with those of two previously reported variants (R103C and D105G). None of the analysed MASP2 variants, with the exception of D105G, interfered with interactions with either MBL or ficolins (H and L).
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Affiliation(s)
- X Vallès
- International Research Center in Health of Barcelona (CRESIB), Hospital Clínic de Barcelona/IDIBAPS, Barcelona, Spain
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100
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Cestari IDS, Krarup A, Sim RB, Inal JM, Ramirez MI. Role of early lectin pathway activation in the complement-mediated killing of Trypanosoma cruzi. Mol Immunol 2009; 47:426-37. [PMID: 19783051 DOI: 10.1016/j.molimm.2009.08.030] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 08/21/2009] [Accepted: 08/28/2009] [Indexed: 11/15/2022]
Abstract
The complement system is the first line of defence against pathogen infection and can be activated by the classic, alternative and lectin pathways. Trypanosoma cruzi, the causative agent of Chagas disease, has to evade complement system killing and invade the host cells to progress in infection. T. cruzi infectious stages resist complement-mediated killing by expressing surface receptors, which dissociate or prevent C3 convertase formation. Here, we present the first evidence that T. cruzi activates the complement lectin pathway. We detected rapid binding of mannan-binding lectin, H-ficolin, and L-ficolin to the surface of T. cruzi, and found that serum depleted of these molecules failed to kill parasites. Furthermore, lectin pathway activation by T. cruzi required the MBL-associated serine protease 2 (MASP2) activity resulting in C2 factor cleavage. In addition, we demonstrate that the infectious stage of T. cruzi inhibits the lectin pathway activation and complement killing expressing the complement C2 receptor inhibitor trispanning (CRIT) protein. Transgenic parasites overexpressing CRIT were highly resistant to complement-mediated killing. CRIT-derived peptides inhibited both C2 binding to the surface of T. cruzi and parasite killing. Biochemical studies revealed that the CRIT extracellular domain 1 inhibits MASP2 cleavage of C2 factor and thereby impairs C3 convertase formation. Our findings establish that the complement lectin pathway recognizes T. cruzi and provide molecular insights into how the infectious stage inhibits this activation to resist complement system killing.
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Affiliation(s)
- Igor dos S Cestari
- Instituto Oswaldo Cruz-Fiocruz, Laboratório de Biologia Molecular de Parasitas e Vetores, Rio de Janeiro, 21040-900, Brazil
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