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ABSTRACT: The human FCN2 gene codes for ficolin-2 (L-ficolin), a major pattern recognition molecule and activator of the lectin pathway of complement. Seven single nucleotide polymorphisms of this gene were investigated in a large series of cord blood DNA samples. Mutations from the majority to the minority alleles at -602, -4 and +6359 were associated with an increase, while mutations at -986, -557, -64 and +6424 were associated with a decrease, in protein concentration. Full (7 loci) genotypes were obtained for 1229 unrelated neonates, 12 sets of twin siblings and one set of triplets. Forty-four separate genotypes were detected. Four genotypes accounted for more than half the unrelated neonates, and >90% had one of the 12 commonest genotypes. Genotypes were associated with significant differences in mean serum ficolin-2, but the intra-genotype concentration ranges were large and greater than the inter-genotype differences. Consequently, there were no associations between genotypes and low birthweight babies or perinatal infections, and only a weak relationship with preterm deliveries, despite all three adverse pregnancy features being significantly associated with serum ficolin-2 protein. FCN2 genotyping may be of value in clinical studies, but not as a substitute for total serum ficolin-2 protein measurement.
Human immunology 04/2013; · 2.55 Impact Factor
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ABSTRACT: The complement system is an effector mechanism in immunity. It is activated in three ways, the classical, alternative and lectin pathways. The lectin pathway is initiated by the binding of mannose-binding lectin (MBL) or ficolins to carbohydrates on the surfaces of pathogens. In humans, MBL and three types of ficolins (L-ficolin, H-ficolin, and M-ficolin) are present in plasma. Of these lectins, at least, MBL, L-ficolin, and H-ficolin are complexed with three types of MBL-associated serine proteases (MASPs), MASP-1, MASP-2, and MASP-3 and their truncated proteins (MAp44 and sMAP). In the lectin pathway, the lectin-MASP complex (i.e., a complex of lectin, MASPs and their truncated proteins) binds to pathogens, resulting in the activation of C4 and C2 to generate a C3 convertase capable of activating C3. MASP-2 is involved in the activation of C4 and C2. MASP-1 activates C2 and MASP-2. The functions of MASP-3, sMAP, and MAp44 in the lectin pathway remain unknown. MASP-1 and MASP-3 also have a role in the alternative pathway. MBL and ficolins are able to bind to a variety of pathogens depending on their carbohydrate binding specificity, resulting in the activation of the lectin pathway. Deficiencies of the components of the lectin pathway are associated to susceptibility to infection, indicating an important role of the lectin pathway in innate immunity. The lectin-MASP complex is also involved in innate immunity by activating the coagulation system. Recent findings suggest a crucial role of MASP-3 in development.
Archivum Immunologiae et Therapiae Experimentalis 04/2013; · 2.54 Impact Factor
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Yuichi Endo,
Minoru Takahashi,
Daisuke Iwaki,
Yumi Ishida,
Naomi Nakazawa,
Toshihisa Kodama,
Tomohiro Matsuzaka,
Kazuko Kanno,
Yu Liu,
Kohsuke Tsuchiya,
Ikuo Kawamura,
Masahito Ikawa,
Satoshi Waguri,
Ikuo Wada, Misao Matsushita,
Wilhelm J Shwaeble,
Teizo Fujita
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ABSTRACT: Mannose-binding lectin (MBL) and ficolin are complexed with MBL-associated serine proteases, key enzymes of complement activation via the lectin pathway, and act as soluble pattern recognition molecules in the innate immune system. Although numerous reports have revealed the importance of MBL in infectious diseases and autoimmune disorders, the role of ficolin is still unclear. To define the specific role of ficolin in vivo, we generated model mice deficient in ficolins. The ficolin A (FcnA)-deficient (Fcna(-/-)) and FcnA/ficolin B double-deficient (Fcna(-/-)b(-/-)) mice lacked FcnA-mediated complement activation in the sera, because of the absence of complexes comprising FcnA and MBL-associated serine proteases. When the host defense was evaluated by transnasal infection with a Streptococcus pneumoniae strain, which was recognized by ficolins, but not by MBLs, the survival rate was significantly reduced in all three ficolin-deficient (Fcna(-/-), Fcnb(-/-), and Fcna(-/-)b(-/-)) mice compared with wild-type mice. Reconstitution of the FcnA-mediated lectin pathway in vivo improved survival rate in Fcna(-/-) but not in Fcna(-/-)b(-/-) mice, suggesting that both FcnA and ficolin B are essential in defense against S. pneumoniae. These results suggest that ficolins play a crucial role in innate immunity against pneumococcal infection through the lectin complement pathway.
The Journal of Immunology 11/2012; · 5.79 Impact Factor
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Takahiko Horiuchi,
Hiroyuki Ohi,
Isao Ohsawa,
Teizo Fujita, Misao Matsushita,
Noriko Okada,
Tsukasa Seya,
Tetsuro Yamamoto,
Yuichi Endo,
Michiyo Hatanaka,
Nobutaka Wakamiya,
Masashi Mizuno,
Miki Nakao,
Hidechika Okada,
Hiroshi Tsukamoto,
Misako Matsumoto,
Norimitsu Inoue,
Masaru Nonaka,
Taroh Kinoshita
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ABSTRACT: This guideline was provided by the Japanese Association for Complement Research targeting clinicians for making an accurate diagnosis of hereditary angioedema (HAE), and for prompt treatment of the HAE patient in Japan. This is a 2010 year version and will be updated according to any pertinent medical advancements.
Allergology International 10/2012;
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Dong-Jun Jung,
Jang-Hyun An,
Kenji Kurokawa,
Yoon-Chuel Jung,
Min-Jung Kim,
Youko Aoyagi, Misao Matsushita,
Shinji Takahashi,
Hee-Seung Lee,
Kazue Takahashi,
Bok Luel Lee
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ABSTRACT: Wall teichoic acid (WTA) of Staphylococcus aureus is a major cell envelope-associated glycopolymer that is a key molecule in promoting colonization during S. aureus infection. The complement system plays a key role in the opsonization and clearance of pathogens. We recently reported that S. aureus WTA functions as a ligand of human serum mannose-binding lectin (MBL), a recognition molecule of the lectin complement pathway. Intriguingly, serum MBL in adults does not bind to WTA because of an inhibitory effect of serum anti-WTA-IgG. In this study, serum anti-WTA-IgG was purified to homogeneity using a purified S. aureus WTA-coupled affinity column to examine the biological function of human anti-WTA-IgG. The purified anti-WTA-IgG contained the IgG2 subclass as a major component and specifically induced C4 and C3 deposition on the S. aureus surface in the anti-WTA-IgG-depleted serum, but not in C1q-deficient serum. Furthermore, the anti-WTA-IgG-dependent C3 deposition induced phagocytosis of S. aureus cells by human polymorphonuclear leukocytes. These results demonstrate that serum anti-WTA-IgG is a real trigger for the induction of classical complement-dependent opsonophagocytosis against S. aureus. Our results also support the fact that a lack of the lectin complement pathway in MBL-deficient adults is compensated by Ag-specific, Ab-mediated adaptive immunity.
The Journal of Immunology 10/2012; · 5.79 Impact Factor
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Misao Matsushita
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ABSTRACT: Ficolins are a group of multimeric lectins made up of single subunits each of which is composed of a collagen-like domain and a fibrinogen-like domain. Most of the ficolins identified to date bind to acetylated compounds such as N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc). Ficolins in serum are complexed with MBL-associated serine proteases (MASPs) and their truncated proteins. These lectins play an important role in innate immunity. Binding of the ficolin-MASP complex to carbohydrates present on the surface of microbes initiates complement activation via the lectin pathway.
Molecular Immunology 09/2012; · 2.90 Impact Factor
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ABSTRACT: Group B streptococci (GBS; Streptococcus agalactiae) are the most common cause of neonatal sepsis and meningitis. Serotype-specific IgG antibody is known to protect neonates against GBS infections by promoting opsonophagocytosis. The L-ficolin-mediated lectin pathway of the complement is also a potential mechanism for opsonization of GBS, because L-ficolin activates the complement after binding to serotype Ib, III, V, VI, and VIII GBS. In the present study, we investigated how L-ficolin and serotype-specific IgG in cord sera contribute to opsonophagocytic killing of GBS. Neither L-ficolin nor serotype-specific IgG concentrations correlated with C3b deposition on serotype Ib and VI GBS, suggesting L-ficolin- and serotype-specific IgG-independent mechanisms of complement activation. The percentage of serotype VIII GBS killed was high regardless of the concentration of L-ficolin and IgG. In contrast, L-ficolin and serotype-specific IgG can each initiate C3b deposition on serotype III and V GBS and promote phagocytosis by polymorphonuclear leukocytes, but L-ficolin and serotype-specific IgG together promote opsonophagocytic killing to a greater extent than does either alone in vitro. This synergy was observed when serotype III-specific IgG concentrations were between 1 and 6 μg/ml and when serotype V-specific IgG concentrations were between 2 and 5 μg/ml. Concentrations of serotype III-specific IgG in cord blood above 7 μg/ml are considered protective for neonates colonized with GBS, but most neonates with IgG levels of less than 7 μg/ml do not develop GBS infections. The data presented here suggest that L-ficolin enhances opsonophagocytosis of serotype III and V GBS when serotype-specific IgG alone is suboptimal for protection.
Infection and immunity 03/2012; 80(6):2053-60. · 4.21 Impact Factor
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ABSTRACT: Ficolins are thought to be pathogen-associated-molecular-pattern-(PAMP-) recognition molecules that function to support innate immunity. Like mannose-binding lectins (MBLs), most mammalian ficolins form complexes with MBL-associated serine proteases (MASPs), leading to complement activation via the lectin pathway. However, the ability of murine ficolin B, a homologue of human M-ficolin, to perform this function is still controversial. The results of the present study show that ficolin B in mouse bone marrow is an oligomeric protein. Ficolin B, pulled down using GlcNAc-agarose, contained very low, but detectable, amounts of MASP-2 and small MBL-associated protein (sMAP) and showed detectable C4-deposition activity on immobilized N-acetylglucosamine. These biochemical features of ficolin B were confirmed using recombinant mouse ficolin B produced in CHO cells. Taken together, these results suggest that like other mammalian homologues, murine ficolin B has an ability to exert its function via the lectin pathway.
Journal of Biomedicine and Biotechnology 01/2012; 2012:105891. · 2.44 Impact Factor
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Journal of Biomedicine and Biotechnology 01/2012; 2012:275970. · 2.44 Impact Factor
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Mateusz Michalski,
Agnieszka Szala,
Anna St Swierzko,
Jolanta Lukasiewicz,
Anna Maciejewska,
David C Kilpatrick, Misao Matsushita,
Iwona Domzalska-Popadiuk,
Monika Borkowska-Klos,
Anna Sokolowska,
Jerzy Szczapa,
Czeslaw Lugowski,
Maciej Cedzynski
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ABSTRACT: Serum H-ficolin (ficolin-3) concentrations (n=613) and FCN3 genotypes (n=529) from a large group of neonates are presented. Both pre-term deliveries and low birthweight (independently of gestational age) were significantly associated with low H-ficolin concentrations but not with heterozygosity for the FCN3 1637delC frameshift mutation. The presence of the variant allele, however, apparently influenced the protein level. No association of FCN3 gene heterozygosity or relative functional H-ficolin insufficiency (determined as serum level ≤8.6 μg/ml) with perinatal infections was found. One premature newborn, with confirmed infection caused by Streptococcus agalactiae, was H-ficolin-deficient (FCN3 variant homozygote, no detectable protein). We present what is only the fourth case report of total H-ficolin deficiency in the world literature. This neonate was however previously found to be mannan-binding lectin (MBL) as well as MBL-associated serine protease-2 (MASP-2) deficient and also had low serum L-ficolin.
Immunobiology 12/2011; 217(7):730-7. · 3.20 Impact Factor
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ABSTRACT: Mannose-binding lectin (MBL), L-ficolin and MBL associated serine protease-2 (MASP-2) are molecules involved in initiation of the lectin pathway (LP) in the complement system. Although MBL deficiency is observed in almost 10% of healthy people, studies of associations between MBL deficiency and end-stage renal disease (ESRD) remain rare. The objective of the present study is to clarify the significance of the LP in maintenance hemodialysis (HD) patients, especially in terms of MBL levels. Two hundred and forty-four HD patients who had been followed up for 74±84months and 199 healthy controls were included in this study. Measurements of serum concentrations of MBL, L-ficolin, and MASP-2 were performed. Low serum MBL levels (<0.1µg/mL) in the patients were confirmed by examination of a point mutation in the Mbl-2 gene. Seventeen HD patients (7%) and 20 healthy controls (10%) had MBL deficiency. During the follow-up period, 99 patients died. There was no significant difference in the frequency of deaths by infectious diseases between MBL deficient and non-deficient patients. In both patients and healthy controls with MBL deficiency, the serum concentration of L-ficolin tended to be high, and that of MASP-2 was significantly high (P<0.05). MBL deficiency is not a risk factor for HD induction or life-threatening infections. It is postulated that the elevation of concentration of the two components of the LP, L-ficolin and MASP-2, may compensate for the insufficient activity of the LP in MBL deficiency.
Therapeutic apheresis and dialysis: official peer-reviewed journal of the International Society for Apheresis, the Japanese Society for Apheresis, the Japanese Society for Dialysis Therapy 10/2011; 15(5):441-7. · 1.39 Impact Factor
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ABSTRACT: Ficolin-1 (M), ficolin-2 (L), ficolin-3 (H) and mannan-binding lectin (MBL) activate the complement system and have opsonic activity. The specificity of ficolin-3 is poorly characterized and currently limited to a few ligands only. We present new specific targets for human ficolin-3, identified among lipopolysaccharides (LPSs, endotoxin) of Hafnia alvei. The interaction was restricted to LPSs of four strains: 23, Polish Collection of Microorganisms (PCM) 1200, PCM 1203 and PCM 1205 and limited to their O-specific polysaccharides (O-specific PSs) composed of different numbers of oligosaccharide (OS) repeating units (RUs). Moreover, these LPS/ficolin-3 complexes activated the lectin pathway of complement in a C4b-deposition assay in a calcium- and magnesium-dependent way. A neoglycoconjugate of the O-specific PS fraction of H. alvei 1200 LPS with bovine serum albumin (BSA) was prepared and used as a tool for the determination of ficolin-3 concentration and activity in serum. To confirm a structure of the O-specific PS 1200 selected for the conjugate preparation, structural analysis was performed on a series of O-specific PSs released by the mild acid hydrolysis of the LPS. The isolated O-specific PSs, showing the different length distributions, were devoid of a major part of the core OS region and had Hep-Kdo disaccharide at a reducing end. The neoglycoconjugate was a highly selective tool for the determination of ficolin-3 concentration and activity in serum (lectin pathway activation in the C4b deposition assay) and was not affected by MBL, ficolin-1 and ficolin-2 or natural antibodies.
Glycobiology 09/2011; 22(2):267-80. · 3.58 Impact Factor
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ABSTRACT: Mannose-binding lectin (MBL)-associated serine proteases (MASPs) are responsible for activation of the lectin complement pathway. Three types of MASPs (MASP-1, MASP-2, and MASP-3) are complexed with MBL and ficolins in serum. Although MASP-1 and MASP-2 are known to contribute to complement activation, the function of MASP-3 remains unclear. In this study, we investigated the mechanism of MASP-3 activation and its substrate using the recombinant mouse MASP-3 (rMASP-3) and several different types of MASP-deficient mice. A proenzyme rMASP-3 was obtained that was not autoactivated during preparation. The recombinant enzyme was activated by incubation with Staphylococcus aureus in the presence of MBL-A, but not MBL-C. In vivo studies revealed the phagocytic activities of MASP-1/3-deficient mice and all MASPs (MASP-1/2/3)-deficient mice against S. aureus and bacterial clearance in these mice were lower than those in wild-type and MASP-2-deficient mice. Sera from all MASPs-deficient mice showed significantly lower C3 deposition activity on the bacteria compared with that of wild-type serum, and addition of rMASP-3 to the deficient serum restored C3 deposition. The low C3 deposition in sera from all MASPs-deficient mice was probably caused by the low level factor B activation that was ameliorated by the addition of rMASP-3. Furthermore, rMASP-3 directly activated factors B and D in vitro. These results suggested that MASP-3 complexed with MBL is converted to an active form by incubation with bacterial targets, and that activated MASP-3 triggered the initial activation step of the alternative complement pathway.
The Journal of Immunology 08/2011; 187(7):3751-8. · 5.79 Impact Factor
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ABSTRACT: MBL is a serum lectin that activates the lectin pathway of the complement system. MBL forms complexes with three types of MASPs. Upon binding to Salmonella serogroup C-specific oligosaccharide, MBL activates the alternative pathway via a C2-bypass pathway without involving MASP-2, C2 or C4. We demonstrate that mannan-bound MBL activates the alternative pathway via a C2-bypass pathway that requires MASP-2 and C4. Thus, depending on the ligands to which MBL binds, there may be two distinct MBL-mediated C2-bypass pathways.
Microbiology and Immunology 08/2011; 55(11):817-21. · 1.30 Impact Factor
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Seiji Nagamachi,
Isao Ohsawa,
Nobuyuki Sato,
Masaya Ishii,
Gaku Kusaba,
Takashi Kobayashi,
Yukihiko Takeda,
Satoshi Horikoshi,
Hiroyuki Ohi, Misao Matsushita,
Yasuhiko Tomino
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ABSTRACT: A 59-year-old man was diagnosed with IgG4-related tubulointerstitial nephritis. His symptoms as well as laboratory and imaging findings were improved after initiation of steroid therapy. Serologically, he showed hypocomplementemia (C3 23 mg/dl, C4 <2 mg/dl, CH50 <7 U/ml) with high levels of IgG (IgG4 1,970 mg/dl) and immune complexes (C1q assay 8.1 μg/ml) and a low level of C1q (<2.0 mg/dl). Histologically, he also showed linear depositions of IgG, IgM, C3, C4d, C1q, membrane attack complex and all IgG subclasses (IgG1, IgG2, IgG3 and IgG4) along the tubular basement membrane, as well as granular depositions of these components in the renal interstitium. However, mannose-binding lectin and L-ficolin were not detected in these tissues. Homogeneous electron-dense deposits were observed by electron microscopy in the tubular basement membrane. It appears that the immune complexes might activate the classical pathway of the complement in both blood and local tissues in a patient with IgG4-related tubulointerstitial nephritis.
Case reports in nephrology and urology. 07/2011; 1(1):7-14.
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ABSTRACT: Mannose-binding lectin (MBL) is an oligomeric serum lectin involved in innate immunity. Human MBL is complexed with three types of serine proteases (MASP-1, MASP-2 and MASP-3) and two types of their truncated forms (sMAP and MAp44). When an MBL complex binds to carbohydrates of pathogens, the complement system is activated via the lectin pathway. Human MBL is a mixture of different sized oligomers that range mainly from trimers to hexamers. It has been suggested that different MBL oligomers may have distinct MASP compositions. In the present study, an MBL trimer (MBL-I) exclusive of other oligomers was isolated from human serum by chromatography. Immunoblot analysis of MBL-I revealed that it had been co-purified with MASP-1 and sMAP. This suggests that MASP-1 and sMAP are bound to each other in MBL-I. The MBL-I complex was found to activate C2, but to lack the ability to activate C4 due to the absence of MASP-2.
Microbiology and Immunology 03/2011; 55(6):427-33. · 1.30 Impact Factor
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ABSTRACT: Ficolins are a family of oligomeric proteins consisting of an N-terminal collagen-like domain and a C-terminal globular fibrinogen-like domain. They are novel lectins that employ the fibrinogen-like domain as a functional domain. Ficolins specifically recognize N-acetyl compounds such as N-acetylglucosamine, components of bacterial and fungal cell walls, and certain bacteria. Like mannose-binding lectin (MBL), ficolins circulate in complexes with MBL-associated serine proteases (MASPs). MASP complexes form with ficolins and MBL, thereby activating the complement through the lectin pathway. Upon binding of ficolins and MBL to carbohydrates on pathogens, MASPs convert to active forms, and subsequently activate the complement. The activated complements lead to pathogen phagocytosis, aggregation and lysis. In humans, three ficolins (L-, M- and H-ficolins) have been identified, which exhibit differences in tissue expression, protein location site, ligand-binding and bacteria-recognition, suggesting a specific role of each ficolin. In addition, these ficolins form complexes with three MASPs (MASP-1, MASP-2 and MASP-3) and two nonenzymatic proteins (sMAP and MAP-1), suggesting a highly sophisticated organization and regulated activation of the ficolin-dependent lectin pathway. This review provides an overview of our current knowledge of ficolins, especially human ficolins and their mouse homologues. We also discuss their possible physiological roles in innate immunity, especially their defensive role against bacterial infection.
The international journal of biochemistry & cell biology 02/2011; 43(5):705-12. · 4.89 Impact Factor
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Keun-Hwa Park,
Kenji Kurokawa,
Lili Zheng,
Dong-Jun Jung,
Koichiro Tateishi,
Jun-O Jin,
Nam-Chul Ha,
Hee Jung Kang, Misao Matsushita,
Jong-Young Kwak,
Kazue Takahashi,
Bok Luel Lee
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ABSTRACT: Innate immunity is the first line of host defense against invading pathogens, and it is recognized by a variety of pattern recognition molecules, including mannose-binding lectin (MBL). MBL binds to mannose and N-acetylglucosamine residues present on the glycopolymers of microorganisms. Human serum MBL functions as an opsonin and activates the lectin complement pathway. However, which glycopolymer of microorganism is recognized by MBL is still uncertain. Here, we show that wall teichoic acid of Staphylococcus aureus, a bacterial cell surface glycopolymer containing N-acetylglucosamine residue, is a functional ligand of MBL. Whereas serum MBL in adults did not bind to wall teichoic acid because of an inhibitory effect of anti-wall teichoic acid antibodies, MBL in infants who had not yet fully developed their adaptive immunity could bind to S. aureus wall teichoic acid and then induced complement C4 deposition. Our data explain the molecular reasons of why MBL-deficient infants are susceptible to S. aureus infection.
Journal of Biological Chemistry 08/2010; 285(35):27167-75. · 4.77 Impact Factor
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ABSTRACT: The aim of our study was to clarify the association between immunoglobulin G(IgG) subclasses and the complement pathway in patients with idiopathic membranous nephropathy (MN). Immunofluorescence (IF) was performed in 16 MN patients and 20 controls using antibodies against IgG, IgA, IgM, C1q, C3c, C4d, IgG1, IgG2, IgG3, IgG4, mannose binding lectin (MBL), C4-binding protein (C4-bp), factor B, C5b-9, and CD59. MN was classified into two types, segmental MN (S-MN; six patients) and global MN (G-MN; ten patients), according to the distribution of IgG deposits along the glomerular capillary wall. No deposition of any antibody was found in the controls. IF revealed IgG1, IgG3, C1q, C3c, C4d, C4-bp, C5b-9, and CD59 deposits in patients with S-MN, whereas IgG1, IgG2, IgG3, IgG4, C3c, C4d, MBL, factor B, C4-bp, C5b-9, and CD59 deposits were detected in those with G-MN. There was a higher deposition of IG1, IgG2, and IgG4 in patients with G-MN than in those with S-MN, whereas the intensity of C1q deposits was higher in S-MN than in G-MN patients. In contrast, the intensity of factor B and MBL was higher in G-MN than in S-MN patients. This is the first report of S-MN patients showing complement activation of the classical pathway associated with IgG1 and IgG3 and G-MN patients showing complement activation of both the alternative and lectin pathways associated with IgG2 and IgG4.
Pediatric Nephrology 02/2010; 25(6):1091-9. · 2.52 Impact Factor
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Misao Matsushita
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ABSTRACT: Ficolins are a group of oligomeric lectins with subunits consisting of both collagen-like and fibrinogen-like domains. The majority of ficolins identified in vertebrates and invertebrates to date recognize N-acetylglucosamine (GlcNAc). X-ray crystallographic analysis of human ficolins has shown that the fibrinogen-like domain binds to the N-acetylated moiety. Ficolins in serum are associated with MBL-associated serine protease (MASP). The ficolin-MASP complex binds directly to carbohydrates present on the surface of a variety of Gram-positive and Gram-negative bacteria through ficolin. Binding of the complex initiates complement activation via the lectin pathway, leading to generation of opsonic fragments of complement components, such as C3b, and to lysis of the bacteria by the membrane attack complex. Thus, serum ficolins play an important role in innate immunity.
Journal of Innate Immunity 01/2010; 2(1):24-32. · 4.21 Impact Factor
