1
|
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
|
2
|
Mills TC, Chapman S, Hutton P, Gordon AC, Bion J, Chiche JD, Holloway PAH, Stüber F, Garrard CS, Hinds CJ, Hill AVS, Rautanen A. Variants in the Mannose-binding Lectin Gene MBL2 do not Associate With Sepsis Susceptibility or Survival in a Large European Cohort. Clin Infect Dis 2015; 61:695-703. [PMID: 25969530 PMCID: PMC4530723 DOI: 10.1093/cid/civ378] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 04/05/2015] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Sepsis is an increasingly common condition, which continues to be associated with unacceptably high mortality. A large number of association studies have investigated susceptibility to, or mortality from, sepsis for variants in the functionally important immune-related gene MBL2. These studies have largely been underpowered and contradictory. METHODS We genotyped and analyzed 4 important MBL2 single nucleotide polymorphisms (SNPs; rs5030737, rs1800450, rs1800451, and rs7096206) in 1839 European community-acquired pneumonia (CAP) and peritonitis sepsis cases, and 477 controls from the United Kingdom. We analyzed the following predefined subgroups and outcomes: 28-day and 6 month mortality from sepsis due to CAP or peritonitis combined, 28-day mortality from CAP sepsis, peritonitis sepsis, pneumococcal sepsis or sepsis in younger patients, and susceptibility to CAP sepsis or pneumococcal sepsis in the United Kingdom. RESULTS There were no significant associations (all P-values were greater than .05 after correction for multiple testing) between MBL2 genotypes and any of our predefined analyses. CONCLUSIONS In this large, well-defined cohort of immune competent adult patients, no associations between MBL2 genotype and sepsis susceptibility or outcome were identified.
Collapse
Affiliation(s)
- Tara C Mills
- Wellcome Trust Centre for Human Genetics, University of Oxford
| | - Stephen Chapman
- Wellcome Trust Centre for Human Genetics, University of Oxford
| | | | - Anthony C Gordon
- Section of Anaesthetics, Pain Medicine and Intensive Care, Imperial College London
| | - Julian Bion
- School of Clinical and Experimental Medicine, University of Birmingham, United Kingdom
| | | | - Paul A H Holloway
- Section of Anaesthetics, Pain Medicine and Intensive Care, Imperial College London
| | - Frank Stüber
- Department of Anaesthesiology and Pain Medicine, Bern University Hospital and University of Bern, Switzerland
| | | | - Charles J Hinds
- Barts and The London School of Medicine Queen Mary University of London, United Kingdom
| | - Adrian V S Hill
- Wellcome Trust Centre for Human Genetics, University of Oxford
| | - Anna Rautanen
- Wellcome Trust Centre for Human Genetics, University of Oxford
| | | |
Collapse
|
3
|
Keizer MP, Wouters D, Schlapbach LJ, Kuijpers TW. Restoration of MBL-deficiency: redefining the safety, efficacy and viability of MBL-substitution therapy. Mol Immunol 2014; 61:174-84. [PMID: 25044097 DOI: 10.1016/j.molimm.2014.06.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 05/30/2014] [Accepted: 06/03/2014] [Indexed: 12/28/2022]
Abstract
MBL-deficiency is a commonly occurring deficiency of the innate immune system, affecting a substantial part of the population and has been extensively studied. MBL appears to function as a disease modifier. The role of MBL in different conditions is context-dependent. Many clinical studies show conflicting results, which can be partially explained by different definitions of MBL-deficiency, including phenotype- and genotype-based approaches. In this review we give an overview of literature of MBL, its role in different pathologies, diseases and patient populations. We review MBL replacement studies, and discuss the potential of MBL substitution therapy. We finally suggest that new MBL substitution trials should be conducted within a predefined patient population. MBL-deficiency should be based on serum levels and confirmed by genotyping.
Collapse
Affiliation(s)
- M P Keizer
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner Laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children's Hospital, AMC, University of Amsterdam, Amsterdam, The Netherlands.
| | - D Wouters
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner Laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - L J Schlapbach
- Paediatric Critical Care Research Group, Mater Research, University of Queensland, Brisbane, Australia
| | - T W Kuijpers
- Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children's Hospital, AMC, University of Amsterdam, Amsterdam, The Netherlands; Department of Blood Cell Research, Sanquin Blood Supply, Division Research and Landsteiner Laboratory of the AMC, University of Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
4
|
Fletcher GJ, Gnanamony M, Samuel P, Ismail AM, Kannangai R, Daniel D, Eapen CE, Abraham P. Association of mannose-binding lectin polymorphisms and HBV outcome in a South Indian population. Int J Immunogenet 2010; 37:177-84. [PMID: 20193030 DOI: 10.1111/j.1744-313x.2010.00908.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Mannose binding lectin (MBL) is an important innate immune system pattern recognition molecule. The MBL gene polymorphisms are reported to play a crucial role in outcome of hepatitis B virus (HBV) infection. In this study, we ascertained the association of MBL genotypes with HBV outcome in a South Indian population. The MBL gene polymorphisms at codons 52, 54 and 57 of exon I, and promoter polymorphisms at -221 were typed by polymerase chain reaction-sequence specific primer in spontaneously recovered and in chronic HBV group. The allele frequency of codon 52 'C' was significantly higher in chronic HBV group than in the recovered group (98.5% vs. 93.6%; P = 0.003) and codon 52 'T' was significantly higher in recovered group than in the chronic group (6.4% vs. 1.5%; P = 0.003). In multivariate analysis, after adjusting for age, sex and state of origin, codon 52 'CC' and 'CT' genotypes were significantly associated with chronicity and recovery respectively [odds ratio (OR), 0.25; 95% confidence interval (CI), 0.08-0.80, P = 0.02] in co-dominant analyzing models. This was re-affirmed in analysis performed exclusively on Tamil Nadu subjects (OR, 0.23; 95% CI, 0.06-0.93, P = 0.039). The frequency of low/none haplotype (XY/O) was significantly higher in recovered group than in chronic group (15.6% vs 7.5%) and associated with spontaneous recovery (OR, 2.28; 95% CI, 1.04-4.99, P = 0.035). Our results provide preliminary evidence that inheritance of codon 52 genotypes and XY/O haplotype associated with low MBL level substantially determine the outcome of HBV infection in a sympatrically isolated South Indian population.
Collapse
Affiliation(s)
- G J Fletcher
- Department of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Garred P, Honoré C, Ma YJ, Munthe-Fog L, Hummelshøj T. MBL2, FCN1, FCN2 and FCN3-The genes behind the initiation of the lectin pathway of complement. Mol Immunol 2009; 46:2737-44. [PMID: 19501910 DOI: 10.1016/j.molimm.2009.05.005] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 05/01/2009] [Accepted: 05/03/2009] [Indexed: 10/20/2022]
Abstract
Mannose-binding lectin (MBL) and the ficolins (Ficolin-1, Ficolin-2 and Ficolin-3) are soluble collagen-like proteins that are involved in innate immune defence. They bind sugar structures or acetylated compounds present on microorganisms and on dying host cells and they initiate activation of the lectin complement pathway in varying degrees. Common variant alleles situated both in promoter and structural regions of the human MBL gene (MBL2) influence the stability and the serum concentration of the protein. Although not as thoroughly investigated as the MBL2 gene polymorphisms the ficolin genes (FCNs) also exhibit genetic variations affecting both the serum concentration, stability and binding capacity of the corresponding proteins. Epidemiological studies have suggested that the genetically determined variations in MBL serum concentrations influence the susceptibility to and the course of different types of diseases, while the importance of the ficolins in general and the genetic variation in the FCNs genes in particular is still largely unresolved. This overview will summarize the current molecular knowledge of the human MBL2, FCN1, FCN2 and FCN3 genes.
Collapse
Affiliation(s)
- Peter Garred
- Department of Clinical Immunology, Rigshospitalet, University of Copenhagen, Denmark.
| | | | | | | | | |
Collapse
|
6
|
Than NG, Romero R, Erez O, Kusanovic JP, Tarca AL, Edwin SS, Kim JS, Hassan SS, Espinoza J, Mittal P, Mazaki-Tovi S, Friel L, Gotsch F, Vaisbuch E, Camacho N, Papp Z. A role for mannose-binding lectin, a component of the innate immune system in pre-eclampsia. Am J Reprod Immunol 2009; 60:333-45. [PMID: 18727690 DOI: 10.1111/j.1600-0897.2008.00631.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PROBLEM Mannose-binding lectin (MBL) is a pattern-recognition receptor that activates complement and modulates inflammation. Homozygosity for the most common allele of the MBL2 gene that is associated with high MBL serum concentrations is more prevalent among patients with pre-eclampsia. The objective of this study was to determine maternal plasma MBL concentrations in normal pregnant women and patients with pre-eclampsia. METHOD OF STUDY This cross-sectional study included normal pregnant women (n = 187) and patients with pre-eclampsia (n = 99). Maternal plasma MBL concentrations were determined by ELISA. RESULTS Women with pre-eclampsia had a higher median maternal plasma MBL concentration than normal pregnant women. MBL concentration distribution curves were three-modal, the subintervals in normal pregnancy were low (< 143.7), intermediate (143.7-1898.9) and high (> 1898.9 ng/mL). The proportion of normal pregnant women was larger in the low subinterval, while the proportion of patients with preeclampsia was larger in the high subinterval (P = 0.02). Normal pregnant women in the high subinterval had a larger rate of placental underperfusion than those in the low and intermediate subintervals (P = 0.02). CONCLUSIONS The median maternal plasma MBL concentration is elevated in patients with pre-eclampsia and a larger proportion of these patients are in the high subinterval than normal pregnant women, suggesting that this component of the innate immune system is involved in the mechanisms of disease in pre-eclampsia.
Collapse
Affiliation(s)
- Nandor Gabor Than
- Perinatology Research Branch, NICHD/NIH/DHHS, Wayne State University/Hutzel Women's Hospital, 3990 John R, Box 4, Detroit, MI 48201, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Abstract
MBL (mannose-binding lectin) is primarily a liver-derived collagen-like serum protein. It binds sugar structures on micro-organisms and on dying host cells and is one of the four known mediators that initiate activation of the complement system via the lectin pathway. Common variant alleles situated both in promoter and structural regions of the human MBL gene (MBL2) influence the stability and the serum concentration of the protein. Epidemiological studies have suggested that genetically determined variations in MBL serum concentrations influence the susceptibility to and the course of different types of infectious, autoimmune, neoplastic, metabolic and cardiovascular diseases, but this is still a subject under discussion. The fact that these genetic variations are very frequent, indicates a dual role of MBL. This overview summarizes the current molecular understanding of human MBL2 genetics.
Collapse
|
8
|
Bernig T, Breunis W, Brouwer N, Hutchinson A, Welch R, Roos D, Kuijpers T, Chanock S. An analysis of genetic variation across the MBL2 locus in Dutch Caucasians indicates that 3′ haplotypes could modify circulating levels of mannose-binding lectin. Hum Genet 2005; 118:404-15. [PMID: 16208516 DOI: 10.1007/s00439-005-0053-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Accepted: 08/03/2005] [Indexed: 11/29/2022]
Abstract
Mannose-binding protein (MBL) is a critical component of innate immunity and provides first-line protection against pathogens. Both circulating MBL serum levels and functional activity have been correlated with common genetic variants in the MBL2 gene. Associations between MBL deficiency and severe infections have been reported in immuno-incompetent patients and for autoimmune disorders; however, measured MBL serum levels do not fully correlate with the 'secretor haplotypes'. Previously, the MBL2 locus was resequenced and determined that a recombination hotspot divides MBL2 into two haplotype blocks. It was sought to investigate whether additional variants, in either block structure could associate with MBL serum levels. Therefore, 31 common variants were analysed across the locus in 212 DNA samples of healthy Caucasian individuals with known MBL serum concentrations. The additional 5' variants were in strong linkage to the elements of the 'secretor haplotypes'; functional alleles B, C and D also lie on restricted haplotypes. Four variants in the 3' block (Ex4-1483T>C, Ex4-1067G>A, Ex4-901G>A and Ex4-710G>A) are components of a distinct haplotype block. The results of this study suggest that additional 5' variants as well as markers of distinct 3' haplotype blocks in MBL2 may contribute to circulating protein levels, but further studies are required to confirm these observations. Last, there could be a selective advantage for diversification of the 3' region of the gene.
Collapse
Affiliation(s)
- Toralf Bernig
- Section on Genomic Variation, Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892-4605, USA
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Abstract
Lectins are primordial molecules with multiple known functions. They have been known to exist in fish and other animals for decades and were initially identified as (hem)agglutinins. Demonstration of the importance of vertebrate lectins in innate immunity is a recent effort and is still largely unrealised for fish. This mini-review will tabulate those fish lectins identified since the last major review. In addition, particular lectins for which either functional relevance or functional or structural heterogeneity has been demonstrated are discussed in greater detail.
Collapse
Affiliation(s)
- Spencer Russell
- Fish Pathology Laboratory, Ontario Veterinary College, University of Guelph, Guelph, Ont., Canada N1G 2W1
| | | |
Collapse
|
10
|
Larsen F, Madsen HO, Sim RB, Koch C, Garred P. Disease-associated mutations in human mannose-binding lectin compromise oligomerization and activity of the final protein. J Biol Chem 2004; 279:21302-11. [PMID: 14764589 DOI: 10.1074/jbc.m400520200] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Deficiency of human mannose-binding lectin (MBL) caused by mutations in the coding part of the MBL2 gene is associated with increased risk and severity of infections and autoimmunity. To study the biological consequences of MBL mutations, we expressed wild type MBL and mutated MBL in Chinese hamster ovary cells. The normal MBL cDNA (WT MBL-A) was cloned, and the three known natural and two artificial variants were expressed in Chinese hamster ovary cells. When analyzed, WT MBL-A formed covalently linked higher oligomers with a molecular mass of about 300-450 kDa, corresponding to 12-18 single chains or 4-6 structural units. By contrast, all MBL variants formed a dominant band of about 50 kDa, with increasingly weaker bands at 75, 100, and 125 kDa corresponding to two, three, four, and five chains, respectively. In contrast to WT MBL-A, variant MBL formed noncovalent oligomers containing up to six chains (two structural units). MBL variants bound ligands with a markedly reduced capacity compared with WT MBL-A. Mutations in the collagenous region of human MBL compromise assembly of higher order oligomers, resulting in reduced ligand binding capacity and thus reduced capability to activate complement.
Collapse
Affiliation(s)
- Flemming Larsen
- Department of Clinical Immunology, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen Ø, Denmark.
| | | | | | | | | |
Collapse
|
11
|
Martin P, Lerner A, Johnson L, Lerner DL, Haraguchi S, Good RA, Day NK. Inherited mannose-binding lectin deficiency as evidenced by genetic and immunologic analyses: association with severe recurrent infections. Ann Allergy Asthma Immunol 2003; 91:386-92. [PMID: 14582818 DOI: 10.1016/s1081-1206(10)61686-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Mannose-binding lectin (MBL), an acute-phase serum protein of hepatic origin, plays an essential protective role in host innate immunity in targeting microbial pathogens for destruction via opsonization, enhancement of phagocytosis and complement activation. MBL deficiency, characterized by low serum MBL, has been attributed to genetic mutations in both structural and promoter regions of the gene coding for the protein. Concomitant MBL deficiency in patients with chronic immunologic disease has been associated with increased susceptibility to complicating infections that may hasten disease progression. OBJECTIVE Few cases of inherited MBL deficiency in adults and possible associations with recurrent infection have been reported. To address this issue, we investigated the MBL profile of four generations within a single adult family whose members have experienced a variety of persistent infections. METHODS MBL serum levels and MBL genotypes of each participating family member were ascertained by enzyme-linked immunoadsorbent assay and reverse transcriptase-polymerase chain reaction, respectively. MBL complement activation, as measured by C4b deposition against mannan-coated wells, was assayed using an enzyme-linked immunoadsorbent assay. Routine immunologic and cellular tests were carried out to evaluate the immunologic status of each family member. RESULTS Six of the 7 family members screened carried one or more of the variant MBL alleles in their genotype and had correspondingly low serum MBL and reduced ability to affect C4b opsonization. Medical histories of the participating family members revealed an array of mild to severe recurrent infections despite no apparent immunodeficiency. CONCLUSIONS Our studies show that MBL deficiency is an inherited characteristic and may be a crucial factor in maintaining immunologic health.
Collapse
Affiliation(s)
- Patricia Martin
- All Childrens Hospital/University of South Florida College of Medicine, Department of Pediatrics, Division of Allergy and Immunology, St. Petersburg, Florida 33701, USA
| | | | | | | | | | | | | |
Collapse
|
12
|
Abstract
There is an emerging interest for mannose-binding lectin (MBL) due to its role in innate immunity. In this survey we present a mixture of old and new data describing the effect MBL polymorphisms may have on the level and function of the molecule. Three single nucleotide substitutions in exon 1 of the mbl2 gene cause a dominant decrease of functional MBL in the circulation. Additionally, promoter variants influence expression of MBL. It has been assumed that the structural variant alleles may disrupt the assembly of MBL trimers or accelerate the degradation of the protein, thereby causing the decrease in MBL serum concentrations. We have analysed 1183 different sera in a double sandwich antibody ELISA using the same antibody to capture and detect MBL and find the same results as have been presented previously showing that different MBL promoter alleles have profound effect of on the MBL serum concentration. The use of a new anti-MBL monoclonal antibody, however, has shown that the amount of MBL in the circulation is less dependent on the presence of structural variant alleles than previously anticipated. Molecular characterisation of MBL revealed that sera from donors homozygous for the normal MBL genotype predominantly contained high molecular weight MBL, while sera from individuals heterozygous for the variant alleles contained both high and low molecular weight MBL. The ratio between high and low molecular weight MBL was dependent on the MBL promoter type on the normal haplotype. Sera deriving from individuals homozygous for MBL variant alleles contained mainly low molecular weight MBL. Of the different oligomers of MBL only the high molecular weight forms bound mannan efficiently and activated complement. In contrast to a previous notion, we demonstrate that variant alleles give rise to relatively high levels of MBL in the circulation. However, the variant MBL has lower molecular weight and is dysfunctional compared to normal MBL. The physiological relevance of variant MBL remains to be established.
Collapse
Affiliation(s)
- Peter Garred
- Department of Clinical Immunology, Tissue Typing Laboratory-7631, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark.
| | | | | | | |
Collapse
|
13
|
Vorup-Jensen T, Jensen UB, Liu H, Kawasaki T, Uemura K, Thiel S, Dagnaes-Hansen F, Jensen TG. Tail-vein injection of mannan-binding lectin DNA leads to high expression levels of multimeric protein in liver. Mol Ther 2001; 3:867-74. [PMID: 11407900 DOI: 10.1006/mthe.2001.0335] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The human plasma protein mannan-binding lectin (MBL) is an essential part of the innate immune defense system. Low levels of MBL are associated with recurrent infections and other clinically significant signs of a compromised immune defense. Previous studies have addressed the possibility of reconstitution therapy by the use of recombinant or plasma-derived protein. Natural MBL is a multimeric protein, which consists of up to 18 identical polypeptide chains. Synthesis by in vitro methods of MBL with the proper multimeric structure is difficult. We here report that mice obtain MBL levels comparable to those found in normal human plasma when injected with an MBL expression construct as naked plasmid DNA contained in a large volume of physiologic salt solution. The expression was confined to the liver and high MBL expression levels were obtained with less than 5% of the liver cells transfected. The multimeric structure of the MBL found in plasma of injected mice was similar to that of natural MBL. Thus, liver expression following injection of naked DNA is an alternative to reconstitution therapy with a protein having a complex quaternary structure.
Collapse
Affiliation(s)
- T Vorup-Jensen
- Department of Medical Microbiology and Immunology, University of Aarhus, Aarhus C, 8000, Denmark
| | | | | | | | | | | | | | | |
Collapse
|