1
|
Sutta A, Leemans NN, Ploug M, Rosbjerg A, Del Agua Villa C, Pérez-Alós L, Cyranka L, Vincek AS, de Garay T, Rivera K, Bayarri-Olmos R. CL-11 circulates in serum as functionally distinct isoforms. FASEB J 2024; 38:e23543. [PMID: 38466278 DOI: 10.1096/fj.202301765r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 01/08/2024] [Accepted: 02/23/2024] [Indexed: 03/12/2024]
Abstract
Collectin-11 (CL-11) is a pattern recognition molecule of the lectin pathway capable of interacting with collectin-10 (CL-10) and the MASPs to activate the complement cascade. Alternative splicing of the COLEC11 gene gives rise to two different isoforms found in serum (A and D). These isoforms vary in the length of their collagen-like region, which is involved in the stabilization of the trimeric subunit and the interaction with the MASPs. Here we aim at elucidating the biological differences of naturally occurring CL-11 isoforms A and D. We produced recombinant CL-11 as independent isoforms (CL-11A and CL-11D) and together with CL-10 (CL-10/11A, CL-10/11D). Both CL-11 isoforms associated with CL-10, but CL-11D did so to a lesser extent. CL-10/11 heterocomplexes were composed of trimeric subunits of CL-10 and CL-11, as opposed to CL-10 and CL-11 homotrimers. Heterocomplexes were more stable and migrated with higher apparent molecular weights. Immunoprecipitation of serum CL-11 and subsequent mass spectrometry analysis confirmed that native CL-11 circulates in the form of CL-10/11 heterocomplexes that associate with MASP-1, and MASP-3, but not necessarily MASP-2. Despite a shorter collagen region, CL-11D was capable to bind to the MASPs, suggesting that the missing exon 4 is not required for MASP association CL-11D had a reduced ligand binding compared to full-length CL-11A. Based on its reduced ability to oligomerize, form CL-10/11 heterocomplexes, and bind to ligands, we hypothesize that CL-11D may have a limited complement activation potential compared to full-length CL-11A.
Collapse
Affiliation(s)
- Adrian Sutta
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
- Recombinant Protein and Antibody Unit, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
| | - Nelia Nina Leemans
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
| | - Michael Ploug
- Finsen Laboratory, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Anne Rosbjerg
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
- Recombinant Protein and Antibody Unit, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
| | - Christian Del Agua Villa
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
- Recombinant Protein and Antibody Unit, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
| | - Laura Pérez-Alós
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
| | - Leon Cyranka
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
| | - Adam S Vincek
- Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | | | - Keith Rivera
- Mass Spectrometry Shared Resource, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Rafael Bayarri-Olmos
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
- Recombinant Protein and Antibody Unit, Copenhagen University Hospital: Rigshospital, Copenhagen, Denmark
| |
Collapse
|
2
|
Tsakanova G, Stepanyan A, Steffensen R, Soghoyan A, Jensenius JC, Arakelyan A. Pattern Recognition Molecules of Lectin Complement Pathway in Ischemic Stroke. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2021; 14:1347-1368. [PMID: 34707385 PMCID: PMC8544564 DOI: 10.2147/pgpm.s326242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/15/2021] [Indexed: 11/23/2022]
Abstract
Purpose The current study aimed to investigate in an Armenian population the levels of pattern recognition molecules (PRMs) of lectin complement pathway (LCP), MBL (mannan-binding lectin) and M-ficolin in plasma in ischemic stroke (IS), and the possible association of 11 single nucleotide polymorphisms (SNPs) in MBL2, FCN1 and FCN2 genes. Patients and Methods A total of 122 patients with IS and 150 control subjects were included in this study. Immunofluorometric assays (TRIFMAs) and real-time polymerase chain reactions with TaqMan probes were conducted. Results According to the results, the levels of M-ficolin in IS patients are significantly higher than in control subjects, and the MBL2 rs11003125 and rs12780112 SNPs, as well as MBL2 rs12780112*T and FCN1 rs10120023*T minor alleles (MAs) are negatively associated with the risk of IS. Further, MBL2 rs11003125 and rs1800450 SNPs and the carriage of their MAs, as well as FCN1 rs2989727 SNP and the carriage of FCN1 rs10120023*T MA significantly alter plasma MBL and M-ficolin levels in IS patients, respectively. Five common haplotypes in MBL2 gene and three common haplotypes in FCN1 and FCN2 genes were revealed, among which CGTC was negatively associated with IS and decreasing MBL plasma levels in IS. Conclusion In conclusion, we suggest that LCP PRMs are associated with the risk of developing IS, and may also participate in pathological events leading to post-ischemic brain damage. This study emphasizes the important contribution of alterations of LCP PRMs on genomic and proteomic levels to the pathomechanisms of ischemic stroke, at least in an Armenian population.
Collapse
Affiliation(s)
- Gohar Tsakanova
- Institute of Molecular Biology NAS RA, Yerevan, Armenia.,CANDLE Synchrotron Research Institute, Yerevan, Armenia
| | - Ani Stepanyan
- Institute of Molecular Biology NAS RA, Yerevan, Armenia
| | - Rudi Steffensen
- Department of Clinical Immunology, Aalborg University Hospital, Aalborg, Denmark
| | - Armine Soghoyan
- "Surb Grigor Lusavorich" Medical Center CJSC, Yerevan, Armenia
| | | | | |
Collapse
|
3
|
Okada M, Akimoto T, Ishihara A, Yamauchi K. Expanded collectin family in bullfrog (Rana catesbeiana): Identification and characterization of plasma collectins. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 122:104108. [PMID: 33909995 DOI: 10.1016/j.dci.2021.104108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 06/12/2023]
Abstract
BLAST searches against databases for the bullfrog (Rana catesbeiana), using the collectin sequence previously identified in tadpoles, revealed the presence of at least 20 members of the collectin gene family. Phylogenetic analysis demonstrated that the bullfrog possesses expanded gene subfamilies encoding mannose-binding lectin (MBL) and pulmonary surfactant-associated protein D (PSAPD). Two collectins, of 20 kDa (PSAPD1) and 25 kDa (PSAPD6), were purified as a mixture from adult bullfrog plasma using affinity chromatography. These collectins were present as an oligomer of ~400 kDa in their native state, and showed Ca2+-dependent carbohydrate binding with different sugar preferences. Affinity-purified collectins showed weak E. coli agglutination and bactericidal activities, compared with those of plasma. Although both PSAPD1 and PSAPD6 genes were predominantly expressed in the liver, PSAPD1 transcripts were abundant in adults whereas PSAPD6 transcripts were abundant in tadpoles. The findings indicate that two gene subfamilies in the collectin family have diverged structurally, functionally and transcriptionally in the bullfrog. Rapid expansion of the collectin family in bullfrogs may reflect the onset of sub-functionalization of the prototype MBL gene towards tetrapod MBL and PSAPDs, and may be one means of natural adaptation in the innate immune system to various pathogens in both aquatic and terrestrial environments.
Collapse
Affiliation(s)
- Masako Okada
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka, 422-8529, Japan.
| | - Takanori Akimoto
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka, 422-8529, Japan.
| | - Akinori Ishihara
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka, 422-8529, Japan.
| | - Kiyoshi Yamauchi
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka, 422-8529, Japan.
| |
Collapse
|
4
|
Nakajima A, Okada M, Ishihara A, Yamauchi K. Modulation of plasma protein expression in bullfrog (Rana catesbeiana) tadpoles during seasonal acclimatization and thermal acclimation. Gen Comp Endocrinol 2020; 290:113396. [PMID: 31987871 DOI: 10.1016/j.ygcen.2020.113396] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 12/27/2019] [Accepted: 01/20/2020] [Indexed: 02/07/2023]
Abstract
Biological activities in ectothermic vertebrates depend to a great extent on ambient temperature. Adapting their biological systems to annual or short-term alterations in temperature may play an important role in thermal resistance or overwintering survival. Using SDS-PAGE and western blot, we examined plasma proteins in bullfrog (Rana catesbeiana) tadpoles that were seasonally acclimatized (winter vs. summer) or thermally acclimated (4 °C vs. 21 °C) and identified two season-responsive proteins. The first, transthyretin (TTR), is a plasma thyroid hormone distributor protein that was abundant in summer, and the second is a protein containing C-type lectin-like domain (CTLD) that was abundant in winter and cold acclimation of 4 weeks. Sequence analysis revealed that the C-terminal carbohydrate recognition domain of this CTLD protein (termed collectin X) was highly similar to those of the collectin family members, which participate in complement activation of the innate immune system; however, it lacked most of collagen-like domain. Among the hepatic genes involved in the thyroid system, ttr and dio3 were up-regulated, whereas thra and thrb were down-regulated, in summer acclimatization or warm acclimation. In contrast, the collectin X gene (colectx), as well as colect10 and colect11 in the collectin family involved in the innate immune system, were down-regulated during warm acclimation, although fcn2 in the ficolin family was up-regulated during summer acclimatization and warm acclimation. These findings indicate that seasonal acclimatization and thermal acclimation differentially affect some components of the thyroid and innate immune systems at protein and transcript levels.
Collapse
Affiliation(s)
- Ami Nakajima
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan.
| | - Masako Okada
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan.
| | - Akinori Ishihara
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan.
| | - Kiyoshi Yamauchi
- Department of Biological Science, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan.
| |
Collapse
|
5
|
Albuquerque DAP, Cavalcanti IT, Vasconcelos LRS, Montenegro F, Pereira LMMB, Cavalcanti MSM, Moura P, Júnior LBC, de Almeida SMV, Beltrão EIC. Molecular profile of mannan-binding lectin in hepatitis C patients with MBL gene polymorphisms by a modified mannan-coated nitrocellulose assay. J Immunol Methods 2018; 460:101-106. [PMID: 30056939 DOI: 10.1016/j.jim.2018.06.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 06/25/2018] [Accepted: 06/25/2018] [Indexed: 02/08/2023]
Abstract
The aim of this study was to develop an assay to analyze the serum profile of Mannose-binding lectin (MBL) through a simple and "in-house" method (called "dot-N-man"). Furthermore, the study attempted to associate molecular masses of MBL to the profile of MBL gene polymorphisms in patients with hepatitis C. Heterogeneity in molecular masses of MBL is due to the impairment of oligomers formation, which is linked to genetic polymorphisms in the MBL gene. Individuals with AA genotype (wild-type) produce high-molecular-mass proteins, whereas AO and OO individuals produce intermediate and low-molecular-mass proteins, respectively. Sera of thirty patients carrying the hepatitis C virus (HCV) were investigated using MBL binding assay with mannan-coated nitrocellulose (dot-N-man). Purified MBL was evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Dot-N-Man assay yielded MBL with molecular masses ranging between 55 and 320 kDa, comparable to low and high molecular mass forms of MBL. Nonreducing SDS-PAGE showed high molecular mass bands in all AA individuals while bands of 270 and 205 kDa were observed in sera for a number of patients with AO and OO genotypes, respectively. Immunoblotting confirmed the MBL samples obtained from the dot-N-man. These results provide new insights to understand the MBL molecular forms profile in patients infected with HCV- which could be useful in future investigations on the influence of the MBL structure/genotype on both the progression of infection and the response to hepatitis C therapy.
Collapse
Affiliation(s)
- Diego A P Albuquerque
- Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco, Recife, PE, Brazil
| | - Igor T Cavalcanti
- Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco, Recife, PE, Brazil
| | - Luydson R S Vasconcelos
- Instituto do Fígado e Transplantes de Pernambuco - IFP, Recife, PE, Brazil; Faculdade de Ciências Médicas, Universidade de Pernambuco (UPE), Recife, PE, Brazil; Instituto de Pesquisas Aggeu Magalhães - FIOCRUZ, Recife, PE, Brazil
| | - Francisco Montenegro
- Laboratório de Biologia Molecular de Vírus, Instituto de Ciências Biológicas, Universidade de Pernambuco, Recife, PE, Brazil
| | - Leila M M B Pereira
- Instituto do Fígado e Transplantes de Pernambuco - IFP, Recife, PE, Brazil; Faculdade de Ciências Médicas, Universidade de Pernambuco (UPE), Recife, PE, Brazil
| | - Maria S M Cavalcanti
- Laboratório de Biologia Molecular de Vírus, Instituto de Ciências Biológicas, Universidade de Pernambuco, Recife, PE, Brazil; Faculdade de Ciências Médicas, Universidade de Pernambuco (UPE), Recife, PE, Brazil
| | - Patrícia Moura
- Laboratório de Biologia Molecular de Vírus, Instituto de Ciências Biológicas, Universidade de Pernambuco, Recife, PE, Brazil; Faculdade de Ciências Médicas, Universidade de Pernambuco (UPE), Recife, PE, Brazil
| | - Luiz B C Júnior
- Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco, Recife, PE, Brazil; Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Pernambuco, Recife, PE, Brazil
| | - Sinara Mônica Vitalino de Almeida
- Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco, Recife, PE, Brazil; Universidade de Pernambuco (UPE), Faculdade de Ciências, Educação e Tecnologia de Garanhuns (FACETEG), Garanhuns, PE, Brazil.
| | - Eduardo I C Beltrão
- Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco, Recife, PE, Brazil; Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Pernambuco, Recife, PE, Brazil
| |
Collapse
|
6
|
Fraser RS, Lumsden JS, Lillie BN. Identification of polymorphisms in the bovine collagenous lectins and their association with infectious diseases in cattle. Immunogenetics 2018; 70:533-546. [PMID: 29744529 PMCID: PMC6061482 DOI: 10.1007/s00251-018-1061-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 05/01/2018] [Indexed: 12/30/2022]
Abstract
Infectious diseases are a significant issue in animal production systems, including both the dairy and beef cattle industries. Understanding and defining the genetics of infectious disease susceptibility in cattle is an important step in the mitigation of their impact. Collagenous lectins are soluble pattern recognition receptors that form an important part of the innate immune system, which serves as the first line of host defense against pathogens. Polymorphisms in the collagenous lectin genes have been shown in previous studies to contribute to infectious disease susceptibility, and in cattle, mutations in two collagenous lectin genes (MBL1 and MBL2) are associated with mastitis. To further characterize the contribution of variation in the bovine collagenous lectins to infectious disease susceptibility, we used a pooled NGS approach to identify short nucleotide variants (SNVs) in the collagenous lectins (and regulatory DNA) of cattle with (n = 80) and without (n = 40) infectious disease. Allele frequency analysis identified 74 variants that were significantly (p < 5 × 10−6) associated with infectious disease, the majority of which were clustered in a 29-kb segment upstream of the collectin locus on chromosome 28. In silico analysis of the functional effects of all the variants predicted 11 SNVs with a deleterious effect on protein structure and/or function, 148 SNVs that occurred within potential transcription factor binding sites, and 31 SNVs occurring within potential miRNA binding elements. This study provides a detailed look at the genetic variation of the bovine collagenous lectins and identifies potential genetic markers for infectious disease susceptibility.
Collapse
Affiliation(s)
- R S Fraser
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - J S Lumsden
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.,St. George's University, True Blue, Grenada
| | - B N Lillie
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
| |
Collapse
|
7
|
Mwesigwa S, Moulds JM, Chen A, Flanagan J, Sheehan VA, George A, Hanchard NA. Whole-exome sequencing of sickle cell disease patients with hyperhemolysis syndrome suggests a role for rare variation in disease predisposition. Transfusion 2018; 58:726-735. [PMID: 29210071 PMCID: PMC5847445 DOI: 10.1111/trf.14431] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 10/27/2017] [Accepted: 10/30/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND Hyperhemolysis syndrome (HHS) is an uncommon, but life-threatening, transfusion-related complication of red blood cell transfusion. HHS has predominantly been described in patients with sickle cell disease (SCD) and is difficult to diagnose and treat. The pathogenesis of HHS, including its occurrence in only a subset of apparently susceptible individuals, is poorly understood. We undertook whole-exome sequencing (WES) of 12 SCD-HHS patients to identify shared genetic variants that might be relevant to the development of HHS. STUDY DESIGN AND METHODS DNA from adults with SCD having at least one previous episode of HHS were subject to WES. High-quality variants were passed through a series of bioinformatics filters to identify variants that were uncommon among African populations represented in public databases. Recurrent, putative loss-of-function variants occurring in biologically plausible genes were prioritized and then genotyped in a larger, ancestry-matched cohort of non-HHS controls. RESULTS A rare, heterozygous stop-gain variant (p.Glu210Ter) in MBL2 was significantly enriched among HHS cases (p = 0.002). This variant is predicted to result in a premature termination codon that escapes nonsense-mediated mRNA decay, potentially leading to a novel phenotype. We also observed a complex insertion-deletion variant in the final exon of KLRC3 that was enriched among cases (p = 0.0019), although neither variant was found among seven pediatric SCD-HHS patients. CONCLUSION Our results suggest a potential role for rare genetic defects in the development of HHS among adult SCD patients. Such enriched variants may ultimately be useful for identifying high-risk individuals and informing therapeutic approaches in HHS.
Collapse
Affiliation(s)
- Savannah Mwesigwa
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Collaborative African Genomics Network (CAfGEN), Gaborone, Botswana
- Makerere University, Kampala, Uganda
| | - Joann M Moulds
- Scientific Support Services, LifeShare Blood Centers, Shreveport, Louisiana
| | | | - Jonathan Flanagan
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
- Texas Children's Hospital, Houston, Texas
| | - Vivien A Sheehan
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
- Texas Children's Hospital, Houston, Texas
| | | | - Neil A Hanchard
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
- Collaborative African Genomics Network (CAfGEN), Gaborone, Botswana
| |
Collapse
|
8
|
Kalia N, Singh J, Sharma S, Arora H, Kaur M. Genetic and Phenotypic Screening of Mannose-Binding Lectin in Relation to Risk of Recurrent Vulvovaginal Infections in Women of North India: A Prospective Cohort Study. Front Microbiol 2017; 8:75. [PMID: 28197138 PMCID: PMC5281598 DOI: 10.3389/fmicb.2017.00075] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/11/2017] [Indexed: 12/25/2022] Open
Abstract
Recurrent Vulvovaginal Infections (RVVI) is common problem associated with women of reproductive age. The function and deleterious effect of Mannose Binding Lectin 2 (MBL2) common polymorphisms are reported to be associated with various diseases. However, the role of MBL2 promoter gene polymorphisms and their combined effect with structural variant along with Serum Mannose Binding Lectin (sMBL) levels in RVVI has not been investigated. The study included 258 RVVI cases and 203 age matched healthy controls. These were investigated for the distribution of MBL2 codon 54 and promoter polymorphisms by Amplification Refractory Mutation System-Polymerase Chain Reaction (ARMS-PCR). sMBL levels were quantified by Enzyme Linked Immnosorbent Assay (ELISA). The frequency of X allele and its genotypes was significantly high in cases than controls conferring risk toward RVVI and its types (p < 0.05). The HXPA (OR; 2.0), LXQB (OR; 1.43) haplotypes were associated with susceptibility to RVVI cases while haplotype LYQB significantly protected against RVVI (OR; 0.58), Bacterial Vaginosis (BV) (OR; 0.27) and Mixed Infections (MI) cases (OR; 0.62) with high frequency observed in controls (p < 0.05). Mean sMBL levels were significantly low in RVVI, BV, Vulvovaginal Candidiasis (VVC), and MI cases compared to controls (p < 0.05). VVC patient showed significantly low sMBL levels than RVVI and MI cases (p < 0.05). The mean sMBL levels segregated based on MBL2 genotypes and haplotypes showed significant difference in different cases groups with controls. The findings of the present study suggested that MBL2 Y/X polymorphism and low sMBL levels were associated with susceptibility to RVVI either it is BV, VVC, or MI. Thus MBL deficiency in women with RVVI may contribute to decreased efficiency in clearing of pathogens. Hence, specific measures like administration of purified or recombinant MBL might decrease the incidence of vaginal infections recurrences and more-effective treatment.
Collapse
Affiliation(s)
- Namarta Kalia
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University Amritsar, India
| | - Jatinder Singh
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University Amritsar, India
| | - Sujata Sharma
- Department of Gynaecology and Obstetrics, Bebe Nanki Mother and Child Care Centre, Government Medical College Amritsar, India
| | - Hardesh Arora
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University Amritsar, India
| | - Manpreet Kaur
- Department of Human Genetics, Guru Nanak Dev University Amritsar, India
| |
Collapse
|
9
|
Kjaer TR, Jensen L, Hansen A, Dani R, Jensenius JC, Dobó J, Gál P, Thiel S. Oligomerization of Mannan-binding Lectin Dictates Binding Properties and Complement Activation. Scand J Immunol 2017; 84:12-9. [PMID: 27104295 DOI: 10.1111/sji.12441] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/13/2016] [Indexed: 01/13/2023]
Abstract
The complement system is a part of the innate immune system and is involved in recognition and clearance of pathogens and altered-self structures. The lectin pathway of the complement system is initiated when soluble pattern recognition molecules (PRMs) with collagen-like regions bind to foreign or altered self-surfaces. Associated with the collagen-like stems of these PRMs are three mannan-binding lectin (MBL)-associated serine proteases (MASPs) and two MBL-associated proteins (MAps). The most studied of the PRMs, MBL, is present in serum mainly as trimeric and tetrameric oligomers of the structural subunit. We hypothesized that oligomerization of MBL may influence both the potential to bind to micro organisms and the interaction with the MASPs and MAps, thus influencing the ability to initiate complement activation. When testing binding at 37 °C, we found higher binding of tetrameric MBL to Staphylococcus aureus (S. aureus) than trimeric and dimeric MBL. In serum, we found that tetrameric MBL was the main oligomeric form present in complexes with the MASPs and MAp44. Such preference was confirmed using purified forms of recombinant MBL (rMBL) oligomers, where tetrameric rMBL interacted stronger with all of the MASPs and MAp44, compared to trimeric MBL. As a direct consequence of the weaker interaction with the MASPs, we found that trimeric rMBL was inferior to tetrameric rMBL in activating the complement system. Our data suggest that the oligomeric state of MBL is crucial both for the binding properties and the effector function of MBL.
Collapse
Affiliation(s)
- T R Kjaer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - L Jensen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - A Hansen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - R Dani
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - J C Jensenius
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - J Dobó
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - P Gál
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - S Thiel
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| |
Collapse
|
10
|
Nan R, Furze CM, Wright DW, Gor J, Wallis R, Perkins SJ. Flexibility in Mannan-Binding Lectin-Associated Serine Proteases-1 and -2 Provides Insight on Lectin Pathway Activation. Structure 2017; 25:364-375. [PMID: 28111019 PMCID: PMC5300068 DOI: 10.1016/j.str.2016.12.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 12/08/2016] [Accepted: 12/21/2016] [Indexed: 01/19/2023]
Abstract
The lectin pathway of complement is activated by complexes comprising a recognition component (mannose-binding lectin, serum ficolins, collectin-LK or collectin-K1) and a serine protease (MASP-1 or MASP-2). MASP-1 activates MASP-2, and MASP-2 cleaves C4 and C4b-bound C2. To clarify activation, new crystal structures of Ca2+-bound MASP dimers were determined, together with their solution structures from X-ray scattering, analytical ultracentrifugation, and atomistic modeling. Solution structures of the CUB1-EGF-CUB2 dimer of each MASP indicate that the two CUB2 domains were tilted by as much as 90° compared with the crystal structures, indicating considerable flexibility at the EGF-CUB2 junction. Solution structures of the full-length MASP dimers in their zymogen and activated forms revealed similar structures that were much more bent than anticipated from crystal structures. We conclude that MASP-1 and MASP-2 are flexible at multiple sites and that this flexibility may permit both intra- and inter-complex activation.
Collapse
Affiliation(s)
- Ruodan Nan
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Christopher M Furze
- Departments of Infection, Immunity and Inflammation and Molecular Cell Biology, University of Leicester, University Road, Leicester, LE1 9HN, UK
| | - David W Wright
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Jayesh Gor
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Russell Wallis
- Departments of Infection, Immunity and Inflammation and Molecular Cell Biology, University of Leicester, University Road, Leicester, LE1 9HN, UK
| | - Stephen J Perkins
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK.
| |
Collapse
|
11
|
Kalia N, Sharma A, Kaur M, Kamboj SS, Singh J. A comprehensive in silico analysis of non-synonymous and regulatory SNPs of human MBL2 gene. SPRINGERPLUS 2016; 5:811. [PMID: 27390651 PMCID: PMC4916122 DOI: 10.1186/s40064-016-2543-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 06/08/2016] [Indexed: 12/13/2022]
Abstract
Mannose binding lectin (MBL) is a liver derived protein which plays an important role in innate immunity. Mannose binding lectin gene 2 (MBL2) polymorphisms are reported to be associated with various diseases. In spite of being exhaustively studied molecule, no attempt has been made till date to comprehensively and systematically analyze the SNPs of MBL2 gene. The present study was carried out to identify and prioritize the SNPs of MBL2 gene for further genotyping and functional studies. To predict the possible impact of SNPs on MBL structure and function SNP data obtained from dbSNP database were analyzed using various bioinformatics tools. Out of total 661 SNPs, only 37 validated SNPs having minor allele frequency ≥0.10 were considered for the present study. These 37 SNPs includes one in 3' near gene, nine in 3' UTR, one non-synonymous SNP (nsSNP), thirteen intronic SNPs and thirteen in 5' near gene. From these 37 SNPs, 11 non-coding SNPs were identified to be of functional significance and evolutionary conserved. Out of these, 4 SNPs from 3' UTR were found to play role in miRNA binding, 7 SNPs from 5' near and intronic region were predicted to involve in transcription factor binding and expression of MBL2 gene. One nsSNP Gly54Asp (rs1800450) was found to be deleterious and damaging by both SIFT and Polyphen-2 servers and thus affecting MBL2 protein stability and expression. Protein structural analysis with this amino acid variant was performed by using I-TASSER, RAMPAGE, Swiss-PdbViewer, Chimera and I-mutant. Information regarding solvent accessibility, molecular dynamics and energy minimization calculations showed that this variant causes clashes with neighboring amino acids residues that must interfere in the normal triple helix formation of trimeric subunit and further with the normal assembly of MBL oligomeric form, hence decrease in stability. Thus, findings of the present study indicated 12 SNPs of MBL2 gene to be functionally important. Exploration of these variants may provide novel remedial markers for various diseases.
Collapse
Affiliation(s)
- Namarta Kalia
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, 143005 India
| | - Aarti Sharma
- Department of Human Genetics, Guru Nanak Dev University, Amritsar, India
| | - Manpreet Kaur
- Department of Human Genetics, Guru Nanak Dev University, Amritsar, India
| | - Sukhdev Singh Kamboj
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, 143005 India
| | - Jatinder Singh
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, 143005 India
| |
Collapse
|
12
|
Venkatraman Girija U, Furze CM, Gingras AR, Yoshizaki T, Ohtani K, Marshall JE, Wallis AK, Schwaeble WJ, El-Mezgueldi M, Mitchell DA, Moody PCE, Wakamiya N, Wallis R. Molecular basis of sugar recognition by collectin-K1 and the effects of mutations associated with 3MC syndrome. BMC Biol 2015; 13:27. [PMID: 25912189 PMCID: PMC4431178 DOI: 10.1186/s12915-015-0136-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/01/2015] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Collectin-K1 (CL-K1, or CL-11) is a multifunctional Ca(2+)-dependent lectin with roles in innate immunity, apoptosis and embryogenesis. It binds to carbohydrates on pathogens to activate the lectin pathway of complement and together with its associated serine protease MASP-3 serves as a guidance cue for neural crest development. High serum levels are associated with disseminated intravascular coagulation, where spontaneous clotting can lead to multiple organ failure. Autosomal mutations in the CL-K1 or MASP-3 genes cause a developmental disorder called 3MC (Carnevale, Mingarelli, Malpuech and Michels) syndrome, characterised by facial, genital, renal and limb abnormalities. One of these mutations (Gly(204)Ser in the CL-K1 gene) is associated with undetectable levels of protein in the serum of affected individuals. RESULTS In this study, we show that CL-K1 primarily targets a subset of high-mannose oligosaccharides present on both self- and non-self structures, and provide the structural basis for its ligand specificity. We also demonstrate that three disease-associated mutations prevent secretion of CL-K1 from mammalian cells, accounting for the protein deficiency observed in patients. Interestingly, none of the mutations prevent folding or oligomerization of recombinant fragments containing the mutations in vitro. Instead, they prevent Ca(2+) binding by the carbohydrate-recognition domains of CL-K1. We propose that failure to bind Ca(2+) during biosynthesis leads to structural defects that prevent secretion of CL-K1, thus providing a molecular explanation of the genetic disorder. CONCLUSIONS We have established the sugar specificity of CL-K1 and demonstrated that it targets high-mannose oligosaccharides on self- and non-self structures via an extended binding site which recognises the terminal two mannose residues of the carbohydrate ligand. We have also shown that mutations associated with a rare developmental disorder called 3MC syndrome prevent the secretion of CL-K1, probably as a result of structural defects caused by disruption of Ca(2+) binding during biosynthesis.
Collapse
Affiliation(s)
- Umakhanth Venkatraman Girija
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HN, UK. .,Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK.
| | - Christopher M Furze
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HN, UK.
| | - Alexandre R Gingras
- Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK. .,Department of Medicine, University of California San Diego, La Jolla, CA, 92093-0726, USA.
| | - Takayuki Yoshizaki
- Department of Microbiology and Immunochemistry, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, 078-8510, Japan.
| | - Katsuki Ohtani
- Department of Microbiology and Immunochemistry, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, 078-8510, Japan.
| | - Jamie E Marshall
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HN, UK.
| | - A Katrine Wallis
- Department of Applied Science and Health, Coventry University, Coventry, CV1 5FB, UK.
| | - Wilhelm J Schwaeble
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HN, UK.
| | | | - Daniel A Mitchell
- Clinical Sciences Research Laboratories, Warwick Medical School, University Hospital Coventry & Warwickshire Coventry, Coventry, CV2 2DX, UK.
| | - Peter C E Moody
- Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK.
| | - Nobutaka Wakamiya
- Department of Microbiology and Immunochemistry, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, 078-8510, Japan.
| | - Russell Wallis
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HN, UK. .,Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK.
| |
Collapse
|
13
|
Risteli M, Ruotsalainen H, Bergmann U, Venkatraman Girija U, Wallis R, Myllylä R. Lysyl hydroxylase 3 modifies lysine residues to facilitate oligomerization of mannan-binding lectin. PLoS One 2014; 9:e113498. [PMID: 25419660 PMCID: PMC4242627 DOI: 10.1371/journal.pone.0113498] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 10/24/2014] [Indexed: 01/17/2023] Open
Abstract
Lysyl hydroxylase 3 (LH3) is a multifunctional protein with lysyl hydroxylase, galactosyltransferase and glucosyltransferase activities. The LH3 has been shown to modify the lysine residues both in collagens and also in some collagenous proteins. In this study we show for the first time that LH3 is essential for catalyzing formation of the glucosylgalactosylhydroxylysines of mannan-binding lectin (MBL), the first component of the lectin pathway of complement activation. Furthermore, loss of the terminal glucose units on the derivatized lysine residues in mouse embryonic fibroblasts lacking the LH3 protein leads to defective disulphide bonding and oligomerization of rat MBL-A, with a decrease in the proportion of the larger functional MBL oligomers. The oligomerization could be completely restored with the full length LH3 or the amino-terminal fragment of LH3 that possesses the glycosyltransferase activities. Our results confirm that LH3 is the only enzyme capable of glucosylating the galactosylhydroxylysine residues in proteins with a collagenous domain. In mice lacking the lysyl hydroxylase activity of LH3, but with untouched galactosyltransferase and glucosyltransferase activities, reduced circulating MBL-A levels were observed. Oligomerization was normal, however and residual lysyl hydroxylation was compensated in part by other lysyl hydroxylase isoenzymes. Our data suggest that LH3 is commonly involved in biosynthesis of collagenous proteins and the glucosylation of galactosylhydroxylysines residues by LH3 is crucial for the formation of the functional high-molecular weight MBL oligomers.
Collapse
Affiliation(s)
- Maija Risteli
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Department of Diagnostics and Oral Medicine, Institute of Dentistry, University of Oulu, Oulu, Finland
- Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
- * E-mail:
| | - Heli Ruotsalainen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Ulrich Bergmann
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, Mass Spectrometry Core Facility, University of Oulu, Oulu, Finland
| | | | - Russell Wallis
- Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - Raili Myllylä
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| |
Collapse
|
14
|
Teodorof C, Divakar S, Soontornniyomkij B, Achim CL, Kaul M, Singh KK. Intracellular mannose binding lectin mediates subcellular trafficking of HIV-1 gp120 in neurons. Neurobiol Dis 2014; 69:54-64. [PMID: 24825317 DOI: 10.1016/j.nbd.2014.05.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 04/26/2014] [Accepted: 05/02/2014] [Indexed: 01/19/2023] Open
Abstract
Human immunodeficiency virus-1 (HIV-1) enters the brain early during infection and leads to severe neuronal damage and central nervous system impairment. HIV-1 envelope glycoprotein 120 (gp120), a neurotoxin, undergoes intracellular trafficking and transport across neurons; however mechanisms of gp120 trafficking in neurons are unclear. Our results show that mannose binding lectin (MBL) that binds to the N-linked mannose residues on gp120, participates in intravesicular packaging of gp120 in neuronal subcellular organelles and also in subcellular trafficking of these vesicles in neuronal cells. Perinuclear MBL:gp120 vesicular complexes were observed and MBL facilitated the subcellular trafficking of gp120 via the endoplasmic reticulum (ER) and Golgi vesicles. The functional carbohydrate recognition domain of MBL was required for perinuclear organization, distribution and subcellular trafficking of MBL:gp120 vesicular complexes. Nocodazole, an agent that depolymerizes the microtubule network, abolished the trafficking of MBL:gp120 vesicles, suggesting that these vesicular complexes were transported along the microtubule network. Live cell imaging confirmed the association of the MBL:gp120 complexes with dynamic subcellular vesicles that underwent trafficking in neuronal soma and along the neurites. Thus, our findings suggest that intracellular MBL mediates subcellular trafficking and transport of viral glycoproteins in a microtubule-dependent mechanism in the neurons.
Collapse
Affiliation(s)
- C Teodorof
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - S Divakar
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - B Soontornniyomkij
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - C L Achim
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - M Kaul
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA; Sanford-Burnham Medical Research Institute, 10901 N Torrey Pines Rd, La Jolla, CA, USA
| | - K K Singh
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA.
| |
Collapse
|
15
|
Beltrame MH, Catarino SJ, Goeldner I, Boldt ABW, de Messias-Reason IJ. The lectin pathway of complement and rheumatic heart disease. Front Pediatr 2014; 2:148. [PMID: 25654073 PMCID: PMC4300866 DOI: 10.3389/fped.2014.00148] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 12/29/2014] [Indexed: 12/19/2022] Open
Abstract
The innate immune system is the first line of host defense against infection and is comprised of humoral and cellular mechanisms that recognize potential pathogens within minutes or hours of entry. The effector components of innate immunity include epithelial barriers, phagocytes, and natural killer cells, as well as cytokines and the complement system. Complement plays an important role in the immediate response against microorganisms, including Streptococcus sp. The lectin pathway is one of three pathways by which the complement system can be activated. This pathway is initiated by the binding of mannose-binding lectin (MBL), collectin 11 (CL-K1), and ficolins (Ficolin-1, Ficolin-2, and Ficolin-3) to microbial surface oligosaccharides and acetylated residues, respectively. Upon binding to target molecules, MBL, CL-K1, and ficolins form complexes with MBL-associated serine proteases 1 and 2 (MASP-1 and MASP-2), which cleave C4 and C2 forming the C3 convertase (C4b2a). Subsequent activation of complement cascade leads to opsonization, phagocytosis, and lysis of target microorganisms through the formation of the membrane-attack complex. In addition, activation of complement may induce several inflammatory effects, such as expression of adhesion molecules, chemotaxis and activation of leukocytes, release of reactive oxygen species, and secretion of cytokines and chemokines. In this chapter, we review the general aspects of the structure, function, and genetic polymorphism of lectin-pathway components and discuss most recent understanding on the role of the lectin pathway in the predisposition and clinical progression of Rheumatic Fever.
Collapse
Affiliation(s)
- Marcia Holsbach Beltrame
- Department of Clinical Pathology, Hospital de Clínicas, Universidade Federal do Paraná , Curitiba , Brazil
| | - Sandra Jeremias Catarino
- Department of Clinical Pathology, Hospital de Clínicas, Universidade Federal do Paraná , Curitiba , Brazil
| | - Isabela Goeldner
- Department of Clinical Pathology, Hospital de Clínicas, Universidade Federal do Paraná , Curitiba , Brazil
| | | | | |
Collapse
|
16
|
Degn SE, Thiel S. Humoral Pattern Recognition and the Complement System. Scand J Immunol 2013; 78:181-93. [DOI: 10.1111/sji.12070] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 05/13/2013] [Indexed: 12/16/2022]
Affiliation(s)
- S. E. Degn
- Department of Biomedicine; Aarhus University; Aarhus; Denmark
| | - S. Thiel
- Department of Biomedicine; Aarhus University; Aarhus; Denmark
| |
Collapse
|
17
|
Wang X, Ju Z, Huang J, Hou M, Zhou L, Qi C, Zhang Y, Gao Q, Pan Q, Li G, Zhong J, Wang C. The relationship between the variants of the bovine MBL2 gene and milk production traits, mastitis, serum MBL-C levels and complement activity. Vet Immunol Immunopathol 2012; 148:311-9. [PMID: 22771198 DOI: 10.1016/j.vetimm.2012.06.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 06/12/2012] [Accepted: 06/13/2012] [Indexed: 11/26/2022]
Abstract
Mannose-binding lectin (MBL), a calcium-dependent collagenous lectin, plays an important role in the host immune defence against a wide range of pathogens. There are MBL1 and MBL2 genes which encode the MBL-A and MBL-C proteins, respectively. This study was carried out to investigate the relationship between the variants of the bovine MBL2 gene and milk production traits, mastitis, serum MBL-C levels and hemolytic complement activity in both classical pathway (CH50) and alternative pathway (ACH50) in Chinese Holstein cattle. Four single-nucleotide polymorphisms (SNPs) in the exon 1 of the MBL2 gene in Chinese Holstein cattle and Luxi yellow cattle were identified by the direct sequencing method. The SNP g.201 G>A was identified as a non-synonymous mutation (codon 31, Arg>Gln) at the N-terminus cysteine-rich domain and the SNPs g.234 C>A and g.235 G>A (codon 42) made Pro to Gln at the 1st Gly-X-Y repeat of the collagen-like domain, while the SNP g.244 T>C (codon 45) was identified as a synonymous mutation (Asn>Asn) at the 2 th Gly-X-Y repeat of the collagen-like domain. The SNP markers (g.201 G>A, and g.234 C>A) were significantly correlated with somatic cell score (SCS) (P<0.05). The concentration of MBL-C protein in serum ranges from 0.8 to 7.4 μg/mL by enzyme-linked immunosorbent assay. Six combinations of different haplotypes from the four SNPs were identified in Chinese Holstein cattle. Statistical analysis revealed that cows with the haplotype combination H4H5 exhibited the lowest SCS. The CH50 value of H4H5 and H5H5 cow are significantly higher than H2H5 haplotype combination (P<0.05). The association analysis results showed that the haplotype combination H4H5 may be used as a tolerance haplotype combination for the bovine mastitis.
Collapse
Affiliation(s)
- Xinju Wang
- Dairy Cattle Research Center, Shandong Academy of Agricultural Science, Jinan 250131, PR China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Boldt ABW, Goeldner I, de Messias-Reason IJT. Relevance of the lectin pathway of complement in rheumatic diseases. Adv Clin Chem 2012; 56:105-53. [PMID: 22397030 DOI: 10.1016/b978-0-12-394317-0.00012-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Due to its importance both in the clearance of pathogens that contribute as rheumatic etiological agents and in the disposal of apoptotic bodies and potential autoimmune initiators, deficiencies of the components of the lectin pathway of complement have been found to increase susceptibility and modulate the severity of most rheumatic disorders. This chapter introduces the general aspects of the structure, function, and genetics of lectin pathway components and summarizes current knowledge of the field regarding rheumatic diseases predisposition and modulation.
Collapse
Affiliation(s)
- Angelica B W Boldt
- Molecular Immunopathology Laboratory, Department of Medical Pathology, Federal University of Paraná, Curitiba, Brazil
| | | | | |
Collapse
|
19
|
Gingras AR, Girija UV, Keeble AH, Panchal R, Mitchell DA, Moody PCE, Wallis R. Structural basis of mannan-binding lectin recognition by its associated serine protease MASP-1: implications for complement activation. Structure 2012; 19:1635-43. [PMID: 22078562 DOI: 10.1016/j.str.2011.08.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 08/04/2011] [Accepted: 08/17/2011] [Indexed: 01/19/2023]
Abstract
Complement activation contributes directly to health and disease. It neutralizes pathogens and stimulates immune processes. Defects lead to immunodeficiency and autoimmune diseases, whereas inappropriate activation causes self-damage. In the lectin and classical pathways, complement is triggered upon recognition of a pathogen by an activating complex. Here we present the first structure of such a complex in the form of the collagen-like domain of mannan-binding lectin (MBL) and the binding domain of its associated protease (MASP-1/-3). The collagen binds within a groove using a pivotal lysine side chain that interacts with Ca(2+)-coordinating residues, revealing the essential role of Ca(2+). This mode of binding is prototypic for all activating complexes of the lectin and classical pathways, and suggests a general mechanism for the global changes that drive activation. The structural insights reveal a new focus for inhibitors and we have validated this concept by targeting the binding pocket of the MASP.
Collapse
|
20
|
Miller A, Phillips A, Gor J, Wallis R, Perkins SJ. Near-planar solution structures of mannose-binding lectin oligomers provide insight on activation of lectin pathway of complement. J Biol Chem 2012; 287:3930-45. [PMID: 22167201 PMCID: PMC3281675 DOI: 10.1074/jbc.m111.320341] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 12/01/2011] [Indexed: 12/03/2022] Open
Abstract
The complement system is a fundamental component of innate immunity that orchestrates complex immunological and inflammatory processes. Complement comprises over 30 proteins that eliminate invading microorganisms while maintaining host cell integrity. Protein-carbohydrate interactions play critical roles in both the activation and regulation of complement. Mannose-binding lectin (MBL) activates the lectin pathway of complement via the recognition of sugar arrays on pathogenic surfaces. To determine the solution structure of MBL, synchrotron x-ray scattering and analytical ultracentrifugation experiments showed that the carbohydrate-recognition domains in the MBL dimer, trimer, and tetramer are positioned close to each other in near-planar fan-like structures. These data were subjected to constrained modeling fits. A bent structure for the MBL monomer was identified starting from two crystal structures for its carbohydrate-recognition domain and its triple helical region. The MBL monomer structure was used to identify 10-12 near-planar solution structures for each of the MBL dimers, trimers, and tetramers starting from 900 to 6,859 randomized structures for each. These near-planar fan-like solution structures joined at an N-terminal hub clarified how the carbohydrate-recognition domain of MBL binds to pathogenic surfaces. They also provided insight on how MBL presents a structural template for the binding and auto-activation of the MBL-associated serine proteases to initiate the lectin pathway of complement activation.
Collapse
Affiliation(s)
- Ami Miller
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London, WC1E 6BT and
| | - Anna Phillips
- the Department of Infection, Immunity, and Inflammation, Medical Science Building, University of Leicester, University Road, Leicester, LE1 9HN, United Kingdom
| | - Jayesh Gor
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London, WC1E 6BT and
| | - Russell Wallis
- the Department of Infection, Immunity, and Inflammation, Medical Science Building, University of Leicester, University Road, Leicester, LE1 9HN, United Kingdom
| | - Stephen J. Perkins
- From the Department of Structural and Molecular Biology, Darwin Building, University College London, Gower Street, London, WC1E 6BT and
| |
Collapse
|
21
|
Abstract
The ageing process is very complex. Human longevity is a multifactorial trait which is determined by genetic and environmental factors. Twin and family studies imply that up to 25% of human lifespan is heritable. The longevity gene candidates have generally fallen into the following categories: inflammatory and immune-related factors, stress response elements, mediators of glucose and lipid metabolism, components of DNA repair and cellular proliferation and mitochondrial DNA haplogroups. Because of the central role of HLA molecules in the development of protective immunity and the extraordinary degree of polymorphism of HLA genes, many studies have addressed the possible impact of these genes on human longevity. Most of the data available so far demonstrated a possible role of HLA class II specificities in human longevity but definitive evidence has remained elusive. Although the data are limited and controversial, it has been hypothesized that longevity could be associated with cytokine gene polymorphisms correlating with different levels of cytokine production, thereby modulating immune responses in health and disease. Because of the essential role of cytokines in immune responses, the regulation of cytokine gene expression and their polymorphic nature, the genetic variations of these loci with functional significance could be appropriate immunogenetic candidate markers implicated in the mechanism of successful ageing and longevity. In addition, several other genes such as Toll-like receptor genes, Cycloxygenases (COX)/Lipoxygenases (LOX), CCR5, NK receptor genes and MBL2 have been assessed as a possible biomarkers associated with ageing. This review will summarize the data on the role of these immune genes in human longevity.
Collapse
Affiliation(s)
- E Naumova
- Department of Clinical Immunology, University Hospital Alexandovska, Sofia, Bulgaria.
| | | | | |
Collapse
|
22
|
Wang C, Liu M, Li Q, Ju Z, Huang J, Li J, Wang H, Zhong J. Three novel single-nucleotide polymorphisms of MBL1 gene in Chinese native cattle and their associations with milk performance traits. Vet Immunol Immunopathol 2011; 139:229-36. [DOI: 10.1016/j.vetimm.2010.10.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 10/20/2010] [Accepted: 10/26/2010] [Indexed: 10/18/2022]
|
23
|
Satomura A, Fujita T, Fuke Y, Yanai M, Kumasaka K, Takayama E, Hamada H, Maruyama T, Nakayama T. Relationship between oligomer and functional serum mannose-binding lectin in chronic renal failure. Eur J Clin Invest 2010; 40:865-73. [PMID: 20624168 DOI: 10.1111/j.1365-2362.2010.02325.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Mannose-binding lectin (MBL) plays an important role in first-line host defence against pathogens via the lectin pathway. The binding affinity for ligands is greatly increased by oligomerization, although the basic triplet does not bind solid phase mannan and cannot activate complement. Besides, MBL is a positive acute-phase protein. In this study, we examined the relationship between oligomer and functional serum MBL in chronic renal failure patients who were either uraemic [Pre-haemodialysis (pre-HD) patients], or who were receiving maintenance haemodialysis treatment (HD patients). MATERIALS AND METHODS This study included a total of 20 Pre-HD patients, 130 HD patients and 28 healthy subjects. The oligomer and functional serum MBL levels were measured using enzyme-linked immunosorbent assays established previously. RESULTS The median serum functional MBL levels were significantly reduced in both Pre-HD and HD patients compared with healthy subjects (P<0·05 for both). Furthermore, the median functional MBL level in Pre-HD patients was significantly lower than that in HD patients (P<0·05). The median serum oligomer MBL levels in both Pre-HD and HD patients were significantly higher compared with healthy subjects (P<0·05 for both). Furthermore, the median oligomer MBL level in HD patients was significantly (P<0·05) higher than that in Pre-HD patients. The ratios of median serum functional MBL levels to oligomer MBL levels were significantly reduced in both Pre-HD and HD patients compared with healthy subjects (P<0·05 for both). CONCLUSIONS We found significant reductions in the ratios of serum functional MBL levels to oligomer MBL levels in HD and Pre-HD patients compared with healthy subjects.
Collapse
Affiliation(s)
- Atsushi Satomura
- Division of Laboratory Medicine, Department of Pathology and Microbiology, Nihon University School of Medicine, Itabashi, Tokyo, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Recombinant form of human wild type mannan-binding lectin (MBL/A) but not its structural variant (MBL/C) promotes phagocytosis of zymosan by activating complement. Mol Immunol 2010; 47:2505-14. [PMID: 20579738 DOI: 10.1016/j.molimm.2010.05.292] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2010] [Accepted: 05/27/2010] [Indexed: 01/22/2023]
Abstract
Mannan-binding lectin (MBL) mediates innate immune responses, such as activation of the complement lectin pathway and phagocytosis, to help fight infections. In the present study, employing recombinant forms of human MBL (rMBL), the role of wild type MBL (rMBL/A) and its structural variant rMBL/C in mediating THP-1 phagocytosis of fluorescent-labeled zymosan was examined and compared to MBL purified from human plasma (pMBL/A). Flow cytometric analyses revealed that opsonization of zymosan with rMBL/A and pMBL/A (0.5-30microg/ml) resulted in a 1.9- and 2.7-fold enhancement in its uptake by THP-1 cells in the presence of serum that was depleted of both MBL and the classical pathway component, C1q (MBL/C1q Dpl serum). In contrast, no enhancement in phagocytosis was observed when zymosan was opsonized with rMBL/C. Addition of MBL monoclonal antibody, EDTA, or mannan to the opsonization reaction mixture inhibited THP-1 phagocytosis of pMBL/A opsonized zymosan. Heat inactivation of MBL/C1q Dpl serum abolished the 2-fold increase in phagocytosis and in the absence of serum the direct opsonic activity of MBL did not contribute significantly to the uptake of zymosan into THP-1 cells. Activation products of complement components C3 and C4 were deposited on zymosan opsonized with pMBL/A and rMBL/A but not rMBL/C indicating that MBL-mediated phagocytosis of zymosan requires activation of the complement lectin pathway. The findings imply that impaired MBL-mediated phagocytosis may put individuals homozygous for the mutant allele MBL/C but not wild type MBL/A at increased risk to infections such as yeast.
Collapse
|
25
|
Kavan D, Kubíčková M, Bílý J, Vaněk O, Hofbauerová K, Mrázek H, Rozbeský D, Bojarová P, Křen V, Žídek L, Sklenář V, Bezouška K. Cooperation between Subunits Is Essential for High-Affinity Binding of N-Acetyl-d-hexosamines to Dimeric Soluble and Dimeric Cellular Forms of Human CD69. Biochemistry 2010; 49:4060-7. [DOI: 10.1021/bi100181a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel Kavan
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague, Czech Republic
- Institute of Microbiology v.v.i., Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
| | - Monika Kubíčková
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 61137 Brno, Czech Republic
| | - Jan Bílý
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague, Czech Republic
| | - Ondřej Vaněk
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague, Czech Republic
- Institute of Microbiology v.v.i., Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
| | - Kateřina Hofbauerová
- Institute of Microbiology v.v.i., Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
| | - Hynek Mrázek
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague, Czech Republic
- Institute of Microbiology v.v.i., Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
| | - Daniel Rozbeský
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague, Czech Republic
- Institute of Microbiology v.v.i., Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
| | - Pavla Bojarová
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague, Czech Republic
- Institute of Microbiology v.v.i., Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
| | - Vladimír Křen
- Institute of Microbiology v.v.i., Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
| | - Lukáš Žídek
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 61137 Brno, Czech Republic
| | - Vladimír Sklenář
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 61137 Brno, Czech Republic
| | - Karel Bezouška
- Department of Biochemistry, Faculty of Science, Charles University, 12840 Prague, Czech Republic
- Institute of Microbiology v.v.i., Academy of Sciences of Czech Republic, 14220 Prague, Czech Republic
| |
Collapse
|
26
|
Venkatraman Girija U, Furze C, Toth J, Schwaeble WJ, Mitchell DA, Keeble AH, Wallis R. Engineering novel complement activity into a pulmonary surfactant protein. J Biol Chem 2010; 285:10546-52. [PMID: 20118239 PMCID: PMC2856262 DOI: 10.1074/jbc.m109.097493] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Complement neutralizes invading pathogens, stimulates inflammatory and adaptive immune responses, and targets non- or altered-self structures for clearance. In the classical and lectin activation pathways, it is initiated when complexes composed of separate recognition and activation subcomponents bind to a pathogen surface. Despite its apparent complexity, recognition-mediated activation has evolved independently in three separate protein families, C1q, mannose-binding lectins (MBLs), and serum ficolins. Although unrelated, all have bouquet-like architectures and associate with complement-specific serine proteases: MBLs and ficolins with MBL-associated serine protease-2 (MASP-2) and C1q with C1r and C1s. To examine the structural requirements for complement activation, we have created a number of novel recombinant rat MBLs in which the position and orientation of the MASP-binding sites have been changed. We have also engineered MASP binding into a pulmonary surfactant protein (SP-A), which has the same domain structure and architecture as MBL but lacks any intrinsic complement activity. The data reveal that complement activity is remarkably tolerant to changes in the size and orientation of the collagenous stalks of MBL, implying considerable rotational and conformational flexibility in unbound MBL. Furthermore, novel complement activity is introduced concurrently with MASP binding in SP-A but is uncontrolled and occurs even in the absence of a carbohydrate target. Thus, the active rather than the zymogen state is default in lectin·MASP complexes and must be inhibited through additional regions in circulating MBLs until triggered by pathogen recognition.
Collapse
|
27
|
Complement activation and disease: protective effects of hyperbilirubinaemia. Clin Sci (Lond) 2009; 118:99-113. [DOI: 10.1042/cs20080540] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Complement, an important effector mechanism of the immune system, is an enzymatic cascade of approx. 30 serum proteins leading to the amplification of a specific humoral response. It can be activated through the classical or alternative pathways, or through the mannose-binding lectin pathway. The activation of the classical pathway is initiated by the binding of the C1 component to antigen-bound antibodies, known as immunocomplexes. C1 is a complex of one molecule of C1q, two molecules of C1r and two molecules of C1s. C1q contains three copies of a Y-shaped fundamental unit with globular heads included in its structure, which play a major role in the interaction with the Fc portion of immunoglobulins. Deficient or exacerbated activation of the complement system leads to diseases of variable severity, and pharmacological inhibition of the complement system is considered as a therapeutic strategy to ameliorate the inflammatory effects of exacerbated complement activation. Bilirubin is a product of haem degradation by the concerted action of haem oxygenase, which converts haem into biliverdin, and biliverdin reductase, which reduces biliverdin to UCB (unconjugated bilirubin). UCB exerts both cytoprotective and cytotoxic effects in a variety of tissues and cells, acting either as an antioxidant at low concentrations or as an oxidant at high concentrations. In the present review, we describe in detail the anti-complement properties of bilirubin, occurring at levels above the UCB concentrations found in normal human serum, as a beneficial effect of potential clinical relevance. We provide evidence that UCB interferes with the interaction between C1q and immunoglobulins, thus inhibiting the initial step in the activation of complement through the classical pathway. A molecular model is proposed for the interaction between UCB and C1q.
Collapse
|
28
|
Wallis R, Mitchell DA, Schmid R, Schwaeble WJ, Keeble AH. Paths reunited: Initiation of the classical and lectin pathways of complement activation. Immunobiology 2009; 215:1-11. [PMID: 19783065 PMCID: PMC2824237 DOI: 10.1016/j.imbio.2009.08.006] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 08/22/2009] [Indexed: 12/16/2022]
Abstract
Understanding the structural organisation and mode of action of the initiating complex of the classical pathway of complement activation (C1) has been a central goal in complement biology since its isolation almost 50 years ago. Nevertheless, knowledge is still incomplete, especially with regard to the interactions between its subcomponents C1q, C1r and C1s that trigger activation upon binding to a microbial target. Recent studies have provided new insights into these interactions, and have revealed unexpected parallels with initiating complexes of the lectin pathway of complement: MBL-MASP and ficolin-MASP. Here, we develop and expand these concepts and delineate their implications towards the key aspects of complement activation via the classical and lectin pathways.
Collapse
Affiliation(s)
- Russell Wallis
- Department of Infection, Immunity and Inflammation, University of Leicester, UK.
| | | | | | | | | |
Collapse
|
29
|
Phillips AE, Toth J, Dodds AW, Girija UV, Furze CM, Pala E, Sim RB, Reid KBM, Schwaeble WJ, Schmid R, Keeble AH, Wallis R. Analogous interactions in initiating complexes of the classical and lectin pathways of complement. THE JOURNAL OF IMMUNOLOGY 2009; 182:7708-17. [PMID: 19494295 DOI: 10.4049/jimmunol.0900666] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The classical and lectin pathways of complement activation neutralize pathogens and stimulate key immunological processes. Both pathways are initiated by collagen-containing, soluble pattern recognition molecules associated with specific serine proteases. In the classical pathway, C1q binds to Ab-Ag complexes or bacterial surfaces to activate C1r and C1s. In the lectin pathway, mannan-binding lectin and ficolins bind to carbohydrates on pathogens to activate mannan-binding lectin-associated serine protease 2. To characterize the interactions leading to classical pathway activation, we have analyzed binding between human C1q, C1r, and C1s, which associate to form C1, using full-length and truncated protease components. We show that C1r and C1s bind to C1q independently. The CUB1-epidermal growth factor fragments contribute most toward binding, but CUB2 of C1r, but not of C1s, is also important. Each C1rs tetramer presents a total of six binding sites, one for each of the collagenous domains of C1q. We also demonstrate that subcomponents of the lectin and classical pathways cross-interact. Thus, although the stoichiometries of complexes differ, interactions are analogous, with equivalent contacts between recognition and protease subcomponents. Importantly, these new data are contrary to existing models of C1 and enable us to propose a new model using mannan-binding lectin-mannan-binding lectin-associated serine protease interactions as a template.
Collapse
Affiliation(s)
- Anna E Phillips
- Department of Infection, University of Leicester, Leicester, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Powlesland AS, Hitchen PG, Parry S, Graham SA, Barrio MM, Elola MT, Mordoh J, Dell A, Drickamer K, Taylor ME. Targeted glycoproteomic identification of cancer cell glycosylation. Glycobiology 2009; 19:899-909. [PMID: 19433864 PMCID: PMC2704901 DOI: 10.1093/glycob/cwp065] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
GalMBP is a fragment of serum mannose-binding protein that has been modified to create a probe for galactose-containing ligands. Glycan array screening demonstrated that the carbohydrate-recognition domain of GalMBP selectively binds common groups of tumor-associated glycans, including Lewis-type structures and T antigen, suggesting that engineered glycan-binding proteins such as GalMBP represent novel tools for the characterization of glycoproteins bearing tumor-associated glycans. Blotting of cell extracts and membranes from MCF7 breast cancer cells with radiolabeled GalMBP was used to demonstrate that it binds to a selected set of high molecular weight glycoproteins that could be purified from MCF7 cells on an affinity column constructed with GalMBP. Proteomic and glycomic analysis of these glycoproteins by mass spectrometry showed that they are forms of CD98hc that bear glycans displaying heavily fucosylated termini, including Lewis(x) and Lewis(y) structures. The pool of ligands was found to include the target ligands for anti-CD15 antibodies, which are commonly used to detect Lewis(x) antigen on tumors, and for the endothelial scavenger receptor C-type lectin, which may be involved in tumor metastasis through interactions with this antigen. A survey of additional breast cancer cell lines reveals that there is wide variation in the types of glycosylation that lead to binding of GalMBP. Higher levels of binding are associated either with the presence of outer-arm fucosylated structures carried on a variety of different cell surface glycoproteins or with the presence of high levels of the mucin MUC1 bearing T antigen.
Collapse
Affiliation(s)
- Alex S Powlesland
- Division of Molecular Biosciences, Department of Life Sciences, Imperial College, London, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Färber K, Cheung G, Mitchell D, Wallis R, Weihe E, Schwaeble W, Kettenmann H. C1q, the recognition subcomponent of the classical pathway of complement, drives microglial activation. J Neurosci Res 2009; 87:644-52. [PMID: 18831010 DOI: 10.1002/jnr.21875] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Microglia, central nervous system (CNS) resident phagocytic cells, persistently police the integrity of CNS tissue and respond to any kind of damage or pathophysiological changes. These cells sense and rapidly respond to danger and inflammatory signals by changing their cell morphology; by release of cytokines, chemokines, or nitric oxide; and by changing their MHC expression profile. We have shown previously that microglial biosynthesis of the complement subcomponent C1q may serve as a reliable marker of microglial activation ranging from undetectable levels of C1q biosynthesis in resting microglia to abundant C1q expression in activated, nonramified microglia. In this study, we demonstrate that cultured microglial cells respond to extrinsic C1q with a marked intracellular Ca(2+) increase. A shift toward proinflammatory microglial activation is indicated by the release of interleukin-6, tumor necrosis factor-alpha, and nitric oxide and the oxidative burst in rat primary microglial cells, an activation and differentiation process similar to the proinflammatory response of microglia to exposure to lipopolysaccharide. Our findings indicate 1) that extrinsic plasma C1q is involved in the initiation of microglial activation in the course of CNS diseases with blood-brain barrier impairment and 2) that C1q synthesized and released by activated microglia is likely to contribute in an autocrine/paracrine way to maintain and balance microglial activation in the diseased CNS tissue.
Collapse
Affiliation(s)
- Katrin Färber
- Cellular Neuroscience, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | | | | | | | | | | | | |
Collapse
|
32
|
Rajagopalan R, Salvi VP, Jensenius JC, Rawal N. New insights on the structural/functional properties of recombinant human mannan-binding lectin and its variants. Immunol Lett 2009; 123:114-24. [PMID: 19428558 DOI: 10.1016/j.imlet.2009.02.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Revised: 02/13/2009] [Accepted: 02/24/2009] [Indexed: 10/21/2022]
Abstract
Inefficient activation of complement lectin pathway in individuals with variant mannan-binding lectin (MBL) genotypes has been attributed to poor formation of higher order oligomers by MBL. But recent studies have shown the presence of large oligomers of MBL (approximately 450 kDa) in serum of individuals with variant MBL alleles. The recombinant forms of MBL (rMBL) variants except MBL/B that assemble into higher order oligomers have not yet been reported. In the present study, structural/functional properties of recombinant forms of wild type MBL (rMBL/A) and its three structural variants, rMBL/B, C, and D generated in insect cells were examined. Western blot analysis indicated covalently linked monomers to hexamers while gel filtration chromatography exhibited non-covalently linked higher order oligomers in addition to prevalent low oligomeric forms. Mannan binding determined by ELISA showed rMBL/A but not the structural variants bind to mannan. Apparent avidity of monoclonal antibody used was found to be about 18- to 52-fold weaker for rMBL structural variants than rMBL/A. Complement activation varied with maximum impairment apparent in rMBL/C followed by rMBL/B, but rMBL/D was functional to the same extent as rMBL/A. Comparison of rMBL/A to MBL purified from plasma (pMBL/A) indicated 8- and 24-fold weaker binding to mannan by BIAcore analysis and ELISA and about 5-fold lesser efficiency in activating complement. The findings provide new insights on the structural/functional properties of rMBL variants and imply that lectin pathway activation may be impaired in individuals, homozygous for the mutant alleles, MBL/C and to a lesser extent MBL/B but not MBL/D.
Collapse
Affiliation(s)
- Rema Rajagopalan
- Department of Biochemistry, University of Texas Health Science Center, 11937, US Highway 271, Tyler, TX 75708-3154, USA
| | | | | | | |
Collapse
|
33
|
Ivanova M, Ruiqing J, Matsushita M, Ogawa T, Kawai S, Ochiai N, Shivarov V, Maruya E, Saji H. MBL2 single nucleotide polymorphism diversity among four ethnic groups as revealed by a bead-based liquid array profiling. Hum Immunol 2008; 69:877-84. [PMID: 18952132 DOI: 10.1016/j.humimm.2008.09.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 08/31/2008] [Accepted: 09/18/2008] [Indexed: 11/30/2022]
Abstract
In the present work we established a rapid, cost-effective and high-throughput method for genotyping using a multiplexed microsphere-based suspension array platform - Luminex xMAP which enabled us to analyze 3 SNPs in the MBL2 gene promoter and 5' UTR, and 3 coding SNPs exon 1 haplotypes, associated with different levels of MBL2 expression. Using this system MBL2 diversity in four different ethnic groups, namely, Asian (Japanese), Caucasian, Hispanic and African-American-assessed. Results showed significant variability in terms of allele, genotype, and haplotype distribution. Characteristic MBL haplotype patterns were defined for each ethnic group. A prevalence of haplotypes coding functional proteins capable of complement activation and pathogen opsonization was observed. Regardless of the significant diversity of individual haplotypes, a high, almost similar (25-28%) proportion of haplotypes associated with MBL deficiency was found in the four ethic groups. The proportion of individuals homozygous for the haplotypes resulting in complete MBL2 deficiency was also significant (2-10%). Considering the role of MBL2 in innate immunity and as a clinically relevant marker, the genotyping approach developed and the knowledge of the genetic variation in different ethnic groups will be relevant to future medical genetic studies.
Collapse
Affiliation(s)
- Milena Ivanova
- Central Laboratory of Clinical Immunology, University Hospital Alexandrovska, Sofia, Bulgaria
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Immunology. PEDIATRIC ALLERGY, ASTHMA AND IMMUNOLOGY 2008. [PMCID: PMC7122665 DOI: 10.1007/978-3-540-33395-1_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The concept of forbidden foods that should not be eaten goes back to the Garden of Eden and apart from its religious meanings it may also have foreshadowed the concept of foods that can provoke adverse reactions. Thus we could say that allergic diseases have plagued mankind since the beginning of life on earth. The prophet Job was affected by a condition that following the rare symptoms described by the Holy Bible might be identified as a severe form of atopic dermatitis (AD). The earliest record of an apparently allergic reaction is 2621 B.C., when death from stinging insects was first described by hieroglyphics carved into the walls of the tomb of Pharaoh Menes depicting his death following the sting of a wasp. In 79 A.D., the death of the Roman admiral Pliny the Elder was ascribed to the SO2-rich gases emanating from the eruption of Mount Vesuvius. Hippocrates (460–377 B.C.) was probably the first to describe how cow’s milk (CM) could cause gastric upset and hives, proposing dietetic measures including both treatment and prevention for CM allergy.
Collapse
|
35
|
Sánchez-Barbero F, Rivas G, Steinhilber W, Casals C. Structural and functional differences among human surfactant proteins SP-A1, SP-A2 and co-expressed SP-A1/SP-A2: role of supratrimeric oligomerization. Biochem J 2007; 406:479-89. [PMID: 17542781 PMCID: PMC2049033 DOI: 10.1042/bj20070275] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
SP-A (surfactant protein A) is a membrane-associated SP that helps to maintain the lung in a sterile and non-inflamed state. Unlike SP-As from other mammalian species, human SP-A consists of two functional gene products: SP-A1 and SP-A2. In all the functions examined, recombinant human SP-A1 invariably exhibits lower biological activity than SP-A2. The objective of the present study was to investigate why SP-A2 possesses greater biological activity than SP-A1 and what advantage accrues to having two polypeptide chains instead of one. We analysed structural and functional characteristics of recombinant baculovirus-derived SP-A1, SP-A2 and co-expressed SP-A1/SP-A2 using a wide array of experimental approaches such as analytical ultracentrifugation, DSC (differential scanning calorimetry) and fluorescence. We found that the extent of supratrimeric assembly is much lower in SP-A1 than SP-A2. However, the resistance to proteolysis is greater for SP-A1 than for SP-A2. Co-expressed SP-A1/SP-A2 had greater thermal stability than SP-A1 and SP-A2 and exhibited properties of each protein. On the one hand, SP-A1/SP-A2, like SP-A2, had a higher degree of oligomerization than SP-A1, and consequently had lower K(d) for binding to bacterial Re-LPS (rough lipopolysaccharide), higher self-association in the presence of calcium and greater capability to aggregate Re-LPS and phospholipids than SP-A1. On the other hand, SP-A1/SP-A2, like SP-A1, was more resistant to trypsin degradation than SP-A2. Finally, the importance of the supratrimeric assembly for SP-A immunomodulatory function is discussed.
Collapse
Affiliation(s)
- Fernando Sánchez-Barbero
- *Departamento de Bioquímica y Biología Molecular I and CIBER (Centro Investigación Biomédica en Red) Enfermedades Respiratorias, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Germán Rivas
- †Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Calle Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Wolfram Steinhilber
- ‡Department of Biotechnology, ALTANA Pharma AG, Byk-Gulden-Strasse 2, 78467 Konstanz, Federal Republic of Germany
| | - Cristina Casals
- *Departamento de Bioquímica y Biología Molecular I and CIBER (Centro Investigación Biomédica en Red) Enfermedades Respiratorias, Universidad Complutense de Madrid, 28040 Madrid, Spain
- To whom correspondence should be addressed (email )
| |
Collapse
|
36
|
Hilgendorff A, Heidinger K, Pfeiffer A, Bohnert A, König IR, Ziegler A, Merz C, Frey G, Chakraborty T, Gortner L, Bein G. Association of polymorphisms in the mannose-binding lectin gene and pulmonary morbidity in preterm infants. Genes Immun 2007; 8:671-7. [PMID: 17898783 DOI: 10.1038/sj.gene.6364432] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Deficiency in the collectin mannose-binding lectin (MBL) increases the risk for pulmonary and systemic infections and its complications in children and adults. The aim of this prospective cohort study was to determine the genetic association of sequence variations within the MBL gene with systemic infections and pulmonary short- and long-term complications in preterm infants below 32 weeks gestational age (GA). Three single-nucleotide polymorphisms (SNPs) in the coding region and one SNP in the promotor region of MBL2 were genotyped by direct sequencing and with sequence-specific probes in 284 newborn infants <32 weeks GA. Clinical variables were comprehensively monitored. An association was found between two SNPs and the development of bronchopulmonary dysplasia (BPD), defined as persistent oxygen requirement at 36 weeks postmenstrual age, adjusting for covariates GA, grade of respiratory distress syndrome and days on mechanical ventilation (rs1800450 (exon 1 at codon 54, B variant): odds ratio dominant model (OR)=3.59, 95% confidence interval (CI)=1.62-7.98; rs7096206 (-221, X variant): OR=2.40, 95% CI=1.16-4.96). Haplotype analyses confirmed the association to BPD, and a single haplotype (frequency 56%) including all SNPs in their wild-type form showed a negative association with the development of BPD. We detected no association between the MBL gene variations and the development of early-onset infections or further pulmonary complications. Frequent variants of the MBL gene, leading to low MBL concentrations, are associated with the diagnosis of BPD in preterm infants. This provides a basis for potential therapeutic options and further genetic and proteomic analysis of the function of MBL in the resistance against pulmonary long-term complications in preterm infants.
Collapse
Affiliation(s)
- A Hilgendorff
- Department of Paediatrics, University of Giessen and Marburg, Giessen, Germany.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Girija UV, Dodds AW, Roscher S, Reid KBM, Wallis R. Localization and characterization of the mannose-binding lectin (MBL)-associated-serine protease-2 binding site in rat ficolin-A: equivalent binding sites within the collagenous domains of MBLs and ficolins. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2007; 179:455-62. [PMID: 17579066 PMCID: PMC2592534 DOI: 10.4049/jimmunol.179.1.455] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ficolins and mannose-binding lectins (MBLs) are the first components of the lectin branch of the complement system. They comprise N-terminal collagen-like domains and C-terminal pathogen-recognition domains (fibrinogen-like domains in ficolins and C-type carbohydrate-recognition domains in MBLs), which target surface-exposed N-acetyl groups or mannose-like sugars on microbial cell walls. Binding leads to activation of MBL-associated serine protease-2 (MASP-2) to initiate complement activation and pathogen neutralization. Recent studies have shown that MASP-2 binds to a short segment of the collagen-like domain of MBL. However, the interaction between ficolins and MASP-2 is relatively poorly understood. In this study, we show that the MASP-2 binding site on rat ficolin-A is also located within the collagen-like domain and encompasses a conserved motif that is present in both MBLs and ficolins. Characterization of this motif using site-directed mutagenesis reveals that a lysine residue in the X position of the Gly-X-Y collagen repeat, Lys(56) in ficolin-A, which is present in all ficolins and MBLs known to activate complement, is essential for MASP-2 binding. Adjacent residues also make important contributions to binding as well as to MASP activation probably by stabilizing the local collagen helix. Equivalent binding sites and comparable activation kinetics of MASP-2 suggest that complement activation by ficolins and MBLs proceeds by analogous mechanisms.
Collapse
Affiliation(s)
| | - Alister W. Dodds
- MRC Immunochemistry Unit, Department of Biochemistry, University of Oxford, Oxford, UK
| | - Silke Roscher
- Departments of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
| | - Kenneth B. M. Reid
- MRC Immunochemistry Unit, Department of Biochemistry, University of Oxford, Oxford, UK
| | - Russell Wallis
- MRC Immunochemistry Unit, Department of Biochemistry, University of Oxford, Oxford, UK
- Departments of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
- Departments of Biochemistry, University of Leicester, Leicester, UK
| |
Collapse
|
38
|
Wang G, Myers C, Mikerov A, Floros J. Effect of cysteine 85 on biochemical properties and biological function of human surfactant protein A variants. Biochemistry 2007; 46:8425-35. [PMID: 17580966 PMCID: PMC2531219 DOI: 10.1021/bi7004569] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Four "core" amino acid differences within the collagen-like domain distinguish the human surfactant protein A1 (SP-A1) variants from the SP-A2 variants. One of these, cysteine 85 that could form intermolecular disulfide bonds, is present in SP-A1 (Cys85) and absent in SP-A2 (Arg85). We hypothesized that residue 85 affects both the structure and function of SP-A1 and SP-A2 variants. To test this, wild-type (WT) variants, 6A2 of SP-A1 and 1A0 of SP-A2, and their mutants (6A2(C85R) and 1A0(R85C)) were generated and studied. We found the following: (1) Residue 85 affected the binding ability to mannose and the oligomerization pattern of SP-As. The 1A0(R85C) and 6A2(C85R) patterns were similar and/or resembled those of WT 6A2 and 1A0, respectively. (2) Both SP-A WT and mutants differentially induced rough LPS and Pseudomonas aeruginosa aggregation in the following order: 1A0 > 6A2 > 6A2(C85R) > 1A0(R85C) for Re-LPS aggregation and 1A0 > 6A2 = 6A2(C85R) = 1A0(R85C) for bacterial aggregation. (3) SP-A WT and mutants enhanced phagocytosis of P. aeruginosa by rat alveolar macrophages. Their phagocytic index order was 6A2(C85R) > 1A0 > 6A2 = 1A0(R85C). The activity of mutant 1A0(C85R) was significantly lower than WT 1A0 but similar to 6A2. Compared to WT 6A2, the 6A2(C85R) mutant exhibited a significantly higher activity. These results indicate that the SP-A variant/mutant with Arg85 exhibits a higher ability to enhance bacterial phagocytosis than that with Cys85. Residue 85 plays an important role in the structure and function of SP-A and is a major factor for the differences between SP-A1 and SP-A2 variants.
Collapse
Affiliation(s)
- Guirong Wang
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Catherine Myers
- Department of Pediatrics, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Anatoly Mikerov
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Joanna Floros
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
- Department of Pediatrics, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
- Department of Obstetrics and Gynecology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
- * Corresponding author: Joanna Floros, Ph. D. Department of Cellular and Molecular Physiology, H166, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA, Telephone: (717) 531-6972, FAX: (717) 531-7667, E-mail:
| |
Collapse
|
39
|
Hogenkamp A, Herías MV, Tooten PCJ, Veldhuizen EJA, Haagsman HP. Effects of surfactant protein D on growth, adhesion and epithelial invasion of intestinal Gram-negative bacteria. Mol Immunol 2007; 44:3517-27. [PMID: 17477970 DOI: 10.1016/j.molimm.2007.03.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 03/09/2007] [Accepted: 03/14/2007] [Indexed: 11/21/2022]
Abstract
Surfactant protein D (SP-D) interacts with various different microorganisms and plays an important role in pulmonary innate immunity. SP-D expression has also been detected in extrapulmonary tissues, including the gastro-intestinal tract. However, its function in the intestine is unknown and may differ considerably from SP-D functions in the lung. Therefore, the effects of porcine SP-D (pSP-D) on several strains of intestinal bacteria were studied by means of bacterial growth assays, colony-count assays, radial diffusion assays and differential fluorescent staining. Furthermore, the effect of pSP-D on the adhesion- and invasion-characteristics was investigated. All bacterial strains tested in this study were aggregated by pSP-D, but only Escherichia coli K12 was susceptible to pSP-D-mediated growth inhibition. Bacterial membrane integrity of E. coli K12 was affected by pSP-D, but this did not lead to a reduced bacterial viability. Therefore, it is unlikely that pSP-D has a direct antimicrobial effect, and the observed effects are most likely due to pSP-D-mediated bacterial aggregation. The effects of pSP-D on bacterial adhesion and invasion were studied with the porcine intestinal epithelial cell line IPI-2I. Preincubation with pSP-D results in a several-fold increase in adhesion (E. coli and Salmonella) and invasion (Salmonella), but did not affect the IL-8 production induced by the bacteria. Results obtained in this study suggest that pSP-D promotes uptake of pathogenic bacteria by epithelial cells. This may reflect a scavenger function for pSP-D in the intestine, which enables the host to generate a more rapid response to infectious bacteria.
Collapse
Affiliation(s)
- Astrid Hogenkamp
- Department of Infectious Diseases and Immunology, Division Molecular Host Defence, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
40
|
Wallis R, Dodds AW, Mitchell DA, Sim RB, Reid KBM, Schwaeble WJ. Molecular Interactions between MASP-2, C4, and C2 and Their Activation Fragments Leading to Complement Activation via the Lectin Pathway. J Biol Chem 2007; 282:7844-51. [PMID: 17204478 DOI: 10.1074/jbc.m606326200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Activation of component C3 is central to the pathways of complement and leads directly to neutralization of pathogens and stimulation of adaptive immune responses. The convertases that catalyze this reaction assemble from fragments of complement components via multistep reactions. In the lectin pathway, mannose-binding lectin (MBL) and ficolins bind to pathogens and activate MBL-associated serine protease-2 (MASP-2). MASP-2 cleaves C4 releasing C4a and generating C4b, which attaches covalently to the pathogen surface upon exposure of its reactive thioester. C2 binds to C4b and is also cleaved by MASP-2 to form the C3 convertase (C4b2a). To understand how this complex process is coordinated, we have analyzed the interactions between MASP-2, C4, C2, and their activation fragments and have compared MASP-2-catalyzed cleavage of C4b2 and C2. The data show that C2 binds tightly to C4b but not to C4, implying that C4 and C2 do not circulate as preformed complexes but that C2 is recruited only after prior activation of C4. Following cleavage of C4, C4b still binds to MASP-2 (KD approximately 0.6 microM) and dissociates relatively slowly (koff approximately 0.06 s-1) compared with the half-life of the thioester (<or=0.7 s) (Sepp, A., Dodds, A. W., Anderson, M. J., Campbell, R. D., Willis, A. C., and Law, S. K. (1993) Protein Sci. 2, 706-716). We propose that the C4b.MASP-2 interaction favors attachment of C4b near to the activating MBL.MASP complex on the bacterial surface so that, following recruitment of C2, the proximity of enzyme and substrate (C4b2) combined with more favorable reaction kinetics drive the formation of the C3 convertase, promoting complement activation.
Collapse
Affiliation(s)
- Russell Wallis
- Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester LE1 9HN, United Kingdom.
| | | | | | | | | | | |
Collapse
|
41
|
Iwaki D, Kanno K, Takahashi M, Endo Y, Lynch NJ, Schwaeble WJ, Matsushita M, Okabe M, Fujita T. Small mannose-binding lectin-associated protein plays a regulatory role in the lectin complement pathway. THE JOURNAL OF IMMUNOLOGY 2007; 177:8626-32. [PMID: 17142762 DOI: 10.4049/jimmunol.177.12.8626] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mannose-binding lectin (MBL) and ficolins are pattern recognition proteins acting in innate immunity, and they trigger the activation of the lectin complement pathway through MBL-associated serine proteases (MASPs). Upon activation of the lectin pathway, MASP-2 cleaves C4 and C2. A truncated form of MASP-2, named small MBL-associated protein (sMAP), is also associated with MBL/ficolin-MASP complexes. To clarify the role of sMAP, we have generated sMAP-deficient (sMAP(-/-)) mice by targeted disruption of the sMAP-specific exon. Because of the gene disruption, the expression level of MASP-2 was also decreased in sMAP(-/-) mice. When recombinant sMAP (rsMAP) and recombinant MASP-2 (rMASP-2) reconstituted the MBL-MASP-sMAP complex in deficient serum, the binding of these recombinant proteins to MBL was competitive, and the C4 cleavage activity of the MBL-MASP-sMAP complex was restored by the addition of rMASP-2, whereas the addition of rsMAP attenuated the activity. Therefore, MASP-2 is essential for the activation of C4 and sMAP plays a regulatory role in the activation of the lectin pathway.
Collapse
Affiliation(s)
- Daisuke Iwaki
- Department of Immunology, Fukushima Medical University, 1-Hikariga-oka, Fukushima City 960-1295, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Wallis R. Interactions between mannose-binding lectin and MASPs during complement activation by the lectin pathway. Immunobiology 2006; 212:289-99. [PMID: 17544814 PMCID: PMC2592599 DOI: 10.1016/j.imbio.2006.11.004] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2006] [Revised: 11/02/2006] [Accepted: 11/07/2006] [Indexed: 11/30/2022]
Abstract
The lectin pathway of complement performs a key role within the immune system by recognising pathogens through patterns of sugar moieties displayed on their cell surfaces and neutralising them via an antibody-independent reaction cascade. While particularly important during early childhood before the adaptive immune system is established, or when adaptive immunity is compromised, it has a protective function throughout life, neutralising invading pathogens directly and helping to stimulate and direct an effective immune response. Complement activation is initiated when complexes comprising mannose-binding lectin (MBL) or serum ficolins and MBL-associated serine protease-2 (MASP-2) bind to pathogens. Binding induces conformational changes in these complexes, leading to autoactivation of the MASPs, which in turn activate the downstream reaction cascade. A major goal in complement research is to understand the molecular events that trigger complement activation. Over the last few years, structure–function studies have improved our knowledge of the way in which MBL binds to MASPs by defining the portions of these proteins that interact and by solving the structures of key protein fragments. In this review, I will summarise the main findings of these studies and describe current theories to explain how the components combine to initiate the reaction cascade.
Collapse
Affiliation(s)
- Russell Wallis
- Departments of Infection, Immunity and Inflammation and Biochemistry, University of Leicester, Leicester, UK.
| |
Collapse
|
43
|
Mayilyan KR, Presanis JS, Arnold JN, Sim RB. Discrete MBL-MASP complexes show wide inter-individual variability in concentration: data from UK vs Armenian populations. Int J Immunopathol Pharmacol 2006; 19:567-80. [PMID: 17026842 DOI: 10.1177/039463200601900313] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Mannan-binding lectin (MBL) circulates in plasma in complex with MBL-associated serine proteases (MASP) -1, -2 and -3 and a smaller component, MAp19. When MBL binds to the surface of foreign material (microorganisms), MASP-1, -2, -3 are activated. MASP-2 then activates the complement system. MASP-1 and -3 may activate other (unidentified) systems. MBL levels, MBL-bound MASP-1 and MBL-bound MASP-2 activities have been evaluated in healthy individuals from UK and Armenian populations. MBL-bound MASP-2 activity declines in aging (P<0.04). MBL correlates with smoking (P<0.02). There were significant differences between the two populations in MBL-bound MASP-1 activity and in MBL, but no difference in MBL-bound MASP-2 activity. When MASP activities were normalised to MBL (i.e. MASP-1 activity/MBL, MASP-2 activity/MBL), normalised MASP-2 activity in UK individuals was more than 2 fold higher than in Armenians. The difference in normalised MASP-2 activity level between these two Caucasoid populations, suggests that concentration of the MBL-(MASP-2) complex, and therefore the function of activating complement, depends not only on the quantity of MBL in serum and its oligomeric state, but also on the quantity of MASP-2 in serum. It is likely that in individuals with high MBL concentration there is excess free MBL not occupied by MASPs, particularly not by MASP-2.
Collapse
Affiliation(s)
- K R Mayilyan
- MRC Immunochemistry Unit, Department of Biochemistry, Oxford University, Oxford, UK
| | | | | | | |
Collapse
|
44
|
Abstract
The human collectin, mannose‐binding lectin (MBL), is an important protein of the humoral innate immune system. With multiple carbohydrate‐recognition domains, it is able to bind to sugar groups displayed on the surfaces of a wide range of microorganisms and thereby provide first‐line defence. Importantly, it also activates the complement system through a distinctive third pathway, independent of both antibody and the C1 complex. Three single point mutations in exon 1 of the expressed human MBL‐2 gene appear to impair the generation of functional oligomers. Such deficiencies of functional protein are common in certain populations, e.g. in sub‐Saharan Africa, but virtually absent in others, e.g. indigenous Australians. MBL disease association studies have been a fruitful area of research and implicate a role for MBL in infective, inflammatory and autoimmune disease processes. Overall, there appears to be a genetic balance in which individuals generally benefit from high levels of the protein. However, in certain situations, reduced levels of circulating MBL may be beneficial to the host and this may explain the persistence of the deleterious gene polymorphisms in many population groups.
Collapse
Affiliation(s)
- R M Dommett
- Infectious Diseases and Microbiology Unit, Institute of Child Health, UCL, 30 Guilford Street, London WC1N 1EH, UK
| | | | | |
Collapse
|
45
|
Lillie BN, Keirstead ND, Squires EJ, Hayes MA. Single-nucleotide polymorphisms in porcine mannan-binding lectin A. Immunogenetics 2006; 58:983-93. [PMID: 17089118 DOI: 10.1007/s00251-006-0160-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2006] [Accepted: 09/06/2006] [Indexed: 10/24/2022]
Abstract
The MBL1 and MBL2 genes encode mannan-binding lectins (MBL) A and C, respectively, that are collagenous lectins (collectins) produced mainly by the liver. Several single-nucleotide polymorphisms (SNPs) in the human MBL2 gene are responsible for various innate immune dysfunctions due to abnormal structure or expression of human MBL-C. The MBL1 gene encodes MBL-A, which has bacteria-binding properties in pigs and rodents but is mutated to a pseudogene in humans and chimpanzees. In these studies, we surveyed both porcine MBL genes for SNPs that might impair disease resistance. Single-strand conformational polymorphism (SSCP) analysis of MBL cDNAs from porcine liver revealed three SNPs within the coding region of MBL1 in various breeds of pigs. One nonsynonymous SNP that substituted cysteine for glycine in the collagen-like domain of pig MBL-A was found by a multiplex PCR test in all European pig breeds examined, with allele frequencies ranging from 1.4 to 46.4%. No SNPs were identified in the coding region of porcine MBL2 but the expression of MBL-C in the liver was widely variable in comparison to the expression of MBL-A, GAPDH, PigMAP, and haptoglobin. These results indicate that some pigs have a miscoding defect in MBL-A and a possible expression defect in MBL-C, which are analogous to coding and promoter polymorphisms that affect human MBL-C.
Collapse
Affiliation(s)
- Brandon N Lillie
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | | | | | | |
Collapse
|
46
|
Podolsky MJ, Lasker A, Flaminio MJBF, Gowda LD, Ezekowitz RAB, Takahashi K. Characterization of an equine mannose-binding lectin and its roles in disease. Biochem Biophys Res Commun 2006; 343:928-36. [PMID: 16574074 DOI: 10.1016/j.bbrc.2006.03.055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Accepted: 03/06/2006] [Indexed: 10/24/2022]
Abstract
The mannose-binding lectin (MBL), a pattern recognition serum protein, participates in the innate immune system of mammals as an opsonin. In humans, MBL plays a key role in first-line host defense against infection during the lag period prior to the development of a specific immune response. MBL also activates complement via the lectin pathway that requires a MBL-associated serine protease-2 (MASP-2). Homologues of human MBL (hMBL) have been identified in a variety of mammals, fish, and primitive animals such as ascidians. In this study, we report that equine MBL (eMBL) has properties that are similar to hMBL. In addition, we found low levels of MBL:MASP activity in sick horses compared to healthy horses. These results suggest that eMBL is involved in the immune response of the horse and that low MBL:MASP activity could be used to monitor immune function and clinical outcome.
Collapse
Affiliation(s)
- Michael J Podolsky
- Laboratory of Developmental Immunology, Department of Pediatrics, Harvard Medical School, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | | | | | | | | | | |
Collapse
|
47
|
Ozaki KI, Miyazaki S, Tanimura S, Kohno M. Efficient suppression of FGF-2-induced ERK activation by the cooperative interaction among mammalian Sprouty isoforms. J Cell Sci 2005; 118:5861-71. [PMID: 16339969 DOI: 10.1242/jcs.02711] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Strict regulation of the receptor tyrosine kinase (RTK)/extracellular signal-regulated kinase (ERK) pathway is essential for maintaining balanced growth in multi-cellular organisms. Several negative regulators of the pathway have been identified which include Sprouty proteins. Mammalian cells express four Sprouty isoforms (Sprouty1-4) in an ERK-dependent manner. In this study, we have examined the molecular mechanisms by which Sprouty proteins elicit their inhibitory effects on the RTK/ERK pathway, with special focus on the co-operation among Sprouty isoforms. The four mammalian Sprouty isoforms interact with each other, most probably to form hetero- as well as homo-oligomers through their C-terminal domains. Sprouty1 specifically interacts with Grb2, whereas Sprouty4 interacts with Sos1. Although any of the Sprouty isoforms by itself inhibits the fibroblast growth factor-2 (FGF-2)-induced activation of the ERK pathway significantly, hetero-oligomers show a more pronounced inhibitory activity. The hetero-oligomer formed between Sprouty1 and Sprouty4 exhibits the most potent inhibitory effect on ERK activation through its highly effective ability to suppress the association of Grb2-Sos1 complex with FRS2. The cooperative interactions observed among Sprouty isoforms could represent an advanced system that functions to regulate strictly the activation state of the RTK/ERK pathway in mammalian cells.
Collapse
Affiliation(s)
- Kei-ichi Ozaki
- Laboratory of Cell Regulation, Department of Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan
| | | | | | | |
Collapse
|
48
|
Hogenkamp A, van Eijk M, van Dijk A, van Asten AJAM, Veldhuizen EJA, Haagsman HP. Characterization and expression sites of newly identified chicken collectins. Mol Immunol 2005; 43:1604-16. [PMID: 16289291 DOI: 10.1016/j.molimm.2005.09.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Accepted: 09/24/2005] [Indexed: 11/17/2022]
Abstract
Collectins are members of the family of vertebrate C-type lectins. They have been found almost exclusively in mammals, with the exception of chicken MBL. Because of their important role in innate immunity, we sought to identify other collectins in chicken. Using the amino acid sequences of known collectins, the EST database was searched and related to the chicken genome. Three chicken collectins were found and designated chicken Collectin 1 (cCL-1), chicken Collectin 2 (cCL-2), and chicken Collectin 3 (cCL-3), which resemble the mammalian proteins Collectin Liver 1, Collectin 11 and Collectin Placenta 1, respectively. Additionally, a lectin was found which resembled Surfactant Protein A, but lacked the collagen domain. Therefore, it was named chicken Lung Lectin (cLL). Tissue distribution analysis showed cCL-1, cCL-2 and cCL-3 are expressed in a wide range of tissues throughout the digestive, the reproductive and the lymphatic system. Similar to SP-A, cLL is mainly localized in lung tissue. Phylogenetic analysis indicates that cCL-1, cCL-2 and cCL-3 represent new subgroups within the collectin family. The newly found collectins may have an important function in avian host defence. Elucidation of the role of these pattern-recognition molecules could lead to strategies that thwart infectious diseases in poultry, which could also be beneficial for public health.
Collapse
Affiliation(s)
- Astrid Hogenkamp
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Graduate School of Animal Health, Utrecht University, P.O. Box 80.165, 3508 TD Utrecht, The Netherlands
| | | | | | | | | | | |
Collapse
|
49
|
Wallis R, Lynch NJ, Roscher S, Reid KB, Schwaeble WJ. Decoupling of Carbohydrate Binding and MASP-2 Autoactivation in Variant Mannose-Binding Lectins Associated with Immunodeficiency. THE JOURNAL OF IMMUNOLOGY 2005; 175:6846-51. [PMID: 16272342 DOI: 10.4049/jimmunol.175.10.6846] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mannan-binding lectin (MBL) initiates complement activation by binding to arrays of carbohydrates on the surfaces of pathogenic microorganisms and activating MBL-associated serine proteases (MASPs). Separate point mutations to the collagenous domain of human MBL are associated with immunodeficiency, caused by reduced complement activation by the variant MBLs as well as by lower serum MBL concentrations. In the work reported here, we have used the well characterized rat lectin pathway to analyze the molecular and functional defects associated with two of the variant proteins. Mutations Gly25 --> Asp and Gly28 --> Glu create comparable structural changes in rat MBL but the G28E variant activates complement >10-fold less efficiently than the G25D variant, which in turn has approximately 7-fold lower activity than wild-type MBL. Analysis of mutant MBL . MASP-2 complexes assembled from recombinant components shows that reduced complement activation by both mutant MBLs is caused by failure to activate MASP-2 efficiently on binding to a mannan-coated surface. Disruption of MBL-MASP-2 interactions as well as to changes in oligomeric structure and reduced binding to carbohydrate ligands compared with wild-type MBL probably account for the intermediate phenotype of the G25D variant. However, carbohydrate binding and MASP-2 activation are ostensibly completely decoupled in complexes assembled from the G28E mutant, such that the rate of MASP-2 activation is no greater than the basal rate of zymogen MASP-2 autoactivation. Analogous molecular defects in human MBL probably combine to create the mutant phenotypes of immunodeficient individuals.
Collapse
Affiliation(s)
- Russell Wallis
- Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom
| | | | | | | | | |
Collapse
|
50
|
Abstract
Mannose-binding lectin (MBL) acts as a serum opsonin in innate immune defense and induces complement activation by the lectin pathway. In humans, low levels of functional serum MBL are caused by the dominant action of three single nucleotide substitutions in exon 1 that disrupt the glycine-rich backbone structure of the protein. The presence of common MBL variant alleles is associated with both infectious and autoimmune diseases. Conversely, it has also been suggested that MBL variants are maintained because of selective advantages for the host. In man, the MBL genetic system comprises one functional gene (MBL2) and one expressed pseudogene (MBL1P1), whereas the lower primate, the rhesus monkey resembles rodents with two functional MBL genes. We have investigated the molecular mechanisms behind the evolutionary loss of MBL expression from lower primates to man, including silencing of the MBL1P1 gene and the generation of MBL2 variant structural alleles and promoter polymorphisms leading to the present human MBL2 haplotypes. We present data showing that the MBL1P1 gene has been repeatedly hit throughout evolution and silenced eventually by mutations in the glycine residues of the collagen-like region. Our results indicate that the MBL1P1 gene has been selectively turned off during evolution through the same molecular mechanisms causing the MBL2 variant alleles in man, suggesting an evolutionary selection for low-producing MBL genes.
Collapse
Affiliation(s)
- Jeanette Seyfarth
- Tissue Typing Laboratory-7631, Department of Clinical Immunology, Rigshospitalet, DK-2100 Copenhagen, Denmark
| | | | | |
Collapse
|