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Sample records for alternative complement activation

  1. Maternal and fetal alternative complement pathway activation in early severe preeclampsia.

    Science.gov (United States)

    Hoffman, M Camille; Rumer, Kristen K; Kramer, Anita; Lynch, Anne M; Winn, Virginia D

    2014-01-01

    We sought to determine whether alternative complement activation fragment Bb (Bb) levels are elevated in the maternal, fetal, and placental blood in cases of severe preeclampsia (PE) compared with normotensive controls. This was a cross-sectional study of women admitted at ≥24 weeks gestation with or without severe PE. Maternal plasma was collected at the time of enrollment. Umbilical venous cord and intervillous space blood were collected at delivery. Plasma Bb levels were assessed using ELISA. Bb levels were compared between cases and controls. Median Bb levels were higher in the maternal plasma of severe PE subjects (n = 24) than in controls (n = 20), 1.45 ± 1.03 versus 0.65 ± 0.23 μg/mL, P < 0.001. In umbilical venous plasma, Bb levels were higher in severe PE subjects (n = 15) compared with controls (n = 15), 2.48 ± 1.40 versus 1.01 ± 0.57 μg/mL, P = 0.01. Activation fragment Bb is increased in the maternal and umbilical venous blood of cases of severe PE when compared with normotensive controls. These data provide support for alternative complement pathway involvement in the pathogenesis of severe PE and demonstrate that alternative complement activation occurs not only in the maternal but also in the fetal compartment. © 2013 John Wiley & Sons Ltd.

  2. Activation capacity of the alternative and classic complement pathways in patients operated on for colorectal cancer

    DEFF Research Database (Denmark)

    Zimmermann-Nielsen, Erik; Iversen, Lene H; Svehag, Sven-Erik

    2002-01-01

    surgery. The samples were analyzed with an enzyme-linked immunosorbent assay that measured C3 activation capacity by the alternative and classic complement pathways. Cancer patients were compared according to Dukes stage, type of surgery performed, transfusion of blood, development of infection, venous....... Significant differences in C3 activation capacities were observed between cancer patients that were related to Dukes stage and in patients with and without buffy coat-depleted red cells suspended in saline, adenine, glucose, and mannitol transfusion, infectious events, and deep venous thromboembolism...

  3. Perioperative functional activity of the alternative pathway of complement in patients with colonic cancer

    DEFF Research Database (Denmark)

    Baatrup, G; Zimmermann-Nielsen, E; Qvist, N

    1999-01-01

    OBJECTIVE: To investigate the functional capacity of the alternative pathway of complement in patients with cancer of the colon before, during, and after operation. DESIGN: Prospective study. SETTING: One university and two district hospitals, Denmark. SUBJECTS: 28 patients having elective...... or emergency operations for colonic cancer. INTERVENTIONS: Measurements of C3b fixing capacity of the alternative complement pathway in serum before, during, and after operation. MAIN OUTCOME MEASUREMENTS: The functional capacity of the alternative pathway of complement, and changes during operation. RESULTS......: The functional capacity of the alternative pathway in patients with cancer of the colon was above normal (p

  4. Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone

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    Bitencourt, C.S. [Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Duarte, C.G.; Azzolini, A.E.C.S.; Assis-Pandochi, A.I. [Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2012-03-02

    Evaluating the activity of the complement system under conditions of altered thyroid hormone levels might help elucidate the role of complement in triggering autoimmune processes. Here, we investigated alternative pathway (AP) activity in male Wistar rats (180 ± 10 g) after altering their thyroid hormone levels by treatment with triiodothyronine (T3), propylthiouracil (PTU) or thyroidectomy. T3 and thyroxine (T4) levels were determined by chemiluminescence assays. Hemolytic assays were performed to evaluate the lytic activity of the AP. Factor B activity was evaluated using factor B-deficient serum. An anti-human factor B antibody was used to measure factor B levels in serum by radial immunodiffusion. T3 measurements in thyroidectomized animals or animals treated with PTU demonstrated a significant reduction in hormone levels compared to control. The results showed a reduction in AP lytic activity in rats treated with increasing amounts of T3 (1, 10, or 50 µg). Factor B activity was also decreased in the sera of hyperthyroid rats treated with 1 to 50 µg T3. Additionally, treating rats with 25 µg T3 significantly increased factor B levels in their sera (P < 0.01). In contrast, increased factor B concentration and activity (32%) were observed in hypothyroid rats. We conclude that alterations in thyroid hormone levels affect the activity of the AP and factor B, which may in turn affect the roles of AP and factor B in antibody production.

  5. Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone

    International Nuclear Information System (INIS)

    Bitencourt, C.S.; Duarte, C.G.; Azzolini, A.E.C.S.; Assis-Pandochi, A.I.

    2012-01-01

    Evaluating the activity of the complement system under conditions of altered thyroid hormone levels might help elucidate the role of complement in triggering autoimmune processes. Here, we investigated alternative pathway (AP) activity in male Wistar rats (180 ± 10 g) after altering their thyroid hormone levels by treatment with triiodothyronine (T3), propylthiouracil (PTU) or thyroidectomy. T3 and thyroxine (T4) levels were determined by chemiluminescence assays. Hemolytic assays were performed to evaluate the lytic activity of the AP. Factor B activity was evaluated using factor B-deficient serum. An anti-human factor B antibody was used to measure factor B levels in serum by radial immunodiffusion. T3 measurements in thyroidectomized animals or animals treated with PTU demonstrated a significant reduction in hormone levels compared to control. The results showed a reduction in AP lytic activity in rats treated with increasing amounts of T3 (1, 10, or 50 µg). Factor B activity was also decreased in the sera of hyperthyroid rats treated with 1 to 50 µg T3. Additionally, treating rats with 25 µg T3 significantly increased factor B levels in their sera (P < 0.01). In contrast, increased factor B concentration and activity (32%) were observed in hypothyroid rats. We conclude that alterations in thyroid hormone levels affect the activity of the AP and factor B, which may in turn affect the roles of AP and factor B in antibody production

  6. Assembly and activation of alternative complement components on endothelial cell-anchored ultra-large von Willebrand factor links complement and hemostasis-thrombosis.

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    Nancy A Turner

    Full Text Available Vascular endothelial cells (ECs express and release protein components of the complement pathways, as well as secreting and anchoring ultra-large von Willebrand factor (ULVWF multimers in long string-like structures that initiate platelet adhesion during hemostasis and thrombosis. The alternative complement pathway (AP is an important non-antibody-requiring host defense system. Thrombotic microangiopathies can be associated with defective regulation of the AP (atypical hemolytic-uremic syndrome or with inadequate cleavage by ADAMTS-13 of ULVWF multimeric strings secreted by/anchored to ECs (thrombotic thrombocytopenic purpura. Our goal was to determine if EC-anchored ULVWF strings caused the assembly and activation of AP components, thereby linking two essential defense mechanisms.We quantified gene expression of these complement components in cultured human umbilical vein endothelial cells (HUVECs by real-time PCR: C3 and C5; complement factor (CF B, CFD, CFP, CFH and CFI of the AP; and C4 of the classical and lectin (but not alternative complement pathways. We used fluorescent microscopy, monospecific antibodies against complement components, fluorescent secondary antibodies, and the analysis of >150 images to quantify the attachment of HUVEC-released complement proteins to ULVWF strings secreted by, and anchored to, the HUVECs (under conditions of ADAMTS-13 inhibition. We found that HUVEC-released C4 did not attach to ULVWF strings, ruling out activation of the classical and lectin pathways by the strings. In contrast, C3, FB, FD, FP and C5, FH and FI attached to ULVWF strings in quantitative patterns consistent with assembly of the AP components into active complexes. This was verified when non-functional FB blocked the formation of AP C3 convertase complexes (C3bBb on ULVWF strings.AP components are assembled and activated on EC-secreted/anchored ULVWF multimeric strings. Our findings provide one possible molecular mechanism for clinical

  7. CR2-mediated activation of the complement alternative pathway results in formation of membrane attack complexes on human B lymphocytes

    DEFF Research Database (Denmark)

    Nielsen, C H; Marquart, H V; Prodinger, W M

    2001-01-01

    the alternative pathway. Blockade of the CR2 ligand-binding site with the monoclonal antibody FE8 resulted in 56 +/- 13% and 71 +/- 9% inhibition of the C3-fragment and MAC deposition, respectively, whereas the monoclonal antibody HB135, directed against an irrelevant CR2 epitope, had no effect. Blockade......Normal human B lymphocytes activate the alternative pathway of complement via complement receptor type 2 (CR2, CD21), that binds hydrolysed C3 (iC3) and thereby promotes the formation of a membrane-bound C3 convertase. We have investigated whether this might lead to the generation of a C5...... processes on CR2, indicate that MAC formation is a consequence of alternative pathway activation....

  8. Multiple activities of LigB potentiate virulence of Leptospira interrogans: inhibition of alternative and classical pathways of complement.

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    Henry A Choy

    Full Text Available Microbial pathogens acquire the immediate imperative to avoid or counteract the formidable defense of innate immunity as soon as they overcome the initial physical barriers of the host. Many have adopted the strategy of directly disrupting the complement system through the capture of its components, using proteins on the pathogen's surface. In leptospirosis, pathogenic Leptospira spp. are resistant to complement-mediated killing, in contrast to the highly vulnerable non-pathogenic strains. Pathogenic L. interrogans uses LenA/LfhA and LcpA to respectively sequester and commandeer the function of two regulators, factor H and C4BP, which in turn bind C3b or C4b to interrupt the alternative or classical pathways of complement activation. LigB, another surface-proximal protein originally characterized as an adhesin binding multiple host proteins, has other activities suggesting its importance early in infection, including binding extracellular matrix, plasma, and cutaneous repair proteins and inhibiting hemostasis. In this study, we used a recent model of ectopic expression of LigB in the saprophyte, L. biflexa, to test the hypothesis that LigB also interacts with complement proteins C3b and C4b to promote the virulence of L. interrogans. The surface expression of LigB partially rescued the non-pathogen from killing by 5% normal human serum, showing 1.3- to 48-fold greater survival 4 to 6 d following exposure to complement than cultures of the non-expressing parental strain. Recombinant LigB7'-12 comprising the LigB-specific immunoglobulin repeats binds directly to human complement proteins, C3b and C4b, with respective K(ds of 43±26 nM and 69±18 nM. Repeats 9 to 11, previously shown to contain the binding domain for fibronectin and fibrinogen, are also important in LigB-complement interactions, which interfere with the alternative and classical pathways measured by complement-mediated hemolysis of erythrocytes. Thus, LigB is an adaptable interface

  9. The down-stream effects of mannan-induced lectin complement pathway activation depend quantitatively on alternative pathway amplification

    DEFF Research Database (Denmark)

    Harboe, Morten; Garred, Peter; Karlstrøm, Ellen

    2009-01-01

    Complement activation plays an important role in human pathophysiology. The effect of classical pathway activation is largely dependent on alternative pathway (AP) amplification, whereas the role of AP for the down-stream effect of mannan-induced lectin pathway (LP) activation is poorly understood...... that AP amplification is quantitatively responsible for the final effect of initial specific LP activation. TCC generation on the solid phase was distinctly but less inhibited by anti-fD. C2 bypass of the LP pathway could be demonstrated, and AP amplification was also essential during C2 bypass in LP...... as shown by complete inhibition of TCC generation in C2-deficient serum by anti-fD and anti-properdin antibodies. In conclusion, the down-stream effect of LP activation depends strongly on AP amplification in normal human serum and in the C2 bypass pathway....

  10. CR2-mediated activation of the complement alternative pathway results in formation of membrane attack complexes on human B lymphocytes

    DEFF Research Database (Denmark)

    Nielsen, C H; Marquart, H V; Prodinger, W M

    2001-01-01

    of the CR1 binding site with the monoclonal antibody 3D9 also resulted in a minor reduction in MAC deposition, while FE8 and 3D9, in combination, markedly reduced deposition of both C3 fragments (91 +/- 5%) and C9 (95 +/- 3%). The kinetics of C3-fragment and MAC deposition, as well as the dependence of both......Normal human B lymphocytes activate the alternative pathway of complement via complement receptor type 2 (CR2, CD21), that binds hydrolysed C3 (iC3) and thereby promotes the formation of a membrane-bound C3 convertase. We have investigated whether this might lead to the generation of a C5...... convertase and consequent formation of membrane attack complexes (MAC). Deposition of C3 fragments and MAC was assessed on human peripheral B lymphocytes in the presence of 30% autologous serum containing 4.4 mM MgCl2/20 mM EGTA, which abrogates the classical pathway of complement without affecting...

  11. Regulation of C3 Activation by the Alternative Complement Pathway in the Mouse Retina.

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    Jennifer A E Williams

    Full Text Available The purpose of this study was to examine the retinas of mice carrying hemizygous and null double deletions of Cfb-/- and Cfh-/-, and to compare these with the single knockouts of Cfb, Cfh and Cfd. Retinas were isolated from wild type (WT, Cfb-/-/Cfh-/-, Cfb-/-/Cfh+/-, Cfh-/-/Cfb+/-, Cfb-/-, Cfh-/- Cfd-/-, and Cfd+/- mice. Complement proteins were evaluated by western blotting, ELISA and immunocytochemistry, and retinal morphology was assessed using toluidine blue stained semi-thin sections. WT mice showed staining for C3 and its breakdown products in the retinal vasculature and the basal surface of the retinal pigment epithelium (RPE. Cfb-/- mice exhibited a similar C3 staining pattern to WT in the retinal vessels but a decrease in C3 and its breakdown products at the basal surface of the RPE. Deletion of both Cfb and Cfh restored C3 to levels similar to those observed in WT mice, however this reversal of phenotype was not observed in Cfh-/-/Cfb+/- or Cfb-/-/Cfh+/- mice. Loss of CFD caused an increase in C3 and a decrease in C3 breakdown products along the basal surface of the RPE. Overall the retinal morphology and retinal vasculature did not appear different across the various genotypes. We observed that C3 accumulates at the basal RPE in Cfb-/-, Cfb-/-/Cfh-/-, Cfb-/-/Cfh+/-, Cfd-/- and WT mice, but is absent in Cfh-/- and Cfh-/-/Cfb+/- mice, consistent with its consumption in the serum of mice lacking CFH when CFB is present. C3 breakdown products along the surface of the RPE were either decreased or absent when CFB, CFH or CFD was deleted or partially deleted.

  12. Material properties in complement activation

    DEFF Research Database (Denmark)

    Moghimi, S. Moein; Andersen, Alina Joukainen; Ahmadvand, Davoud

    2011-01-01

    activation differently and through different sensing molecules and initiation pathways. The importance of material properties in triggering complement is considered and mechanistic aspects discussed. Mechanistic understanding of complement events could provide rational approaches for improved material design...

  13. Combined roles of human IgG subclass, alternative complement pathway activation, and epitope density in the bactericidal activity of antibodies to meningococcal factor h binding protein.

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    Giuntini, Serena; Reason, Donald C; Granoff, Dan M

    2012-01-01

    Meningococcal vaccines containing factor H binding protein (fHbp) are in clinical development. fHbp binds human fH, which enables the meningococcus to resist complement-mediated bacteriolysis. Previously, we found that chimeric human IgG1 mouse anti-fHbp monoclonal antibodies (MAbs) had human complement-mediated bactericidal activity only if the MAb inhibited fH binding. Since IgG subclasses differ in their ability to activate complement, we investigated the role of human IgG subclasses on antibody functional activity. We constructed chimeric MAbs in which three different murine fHbp-specific binding domains were each paired with human IgG1, IgG2, or IgG3. Against a wild-type group B isolate, all three IgG3 MAbs, irrespective of their ability to inhibit fH binding, had bactericidal activity that was >5-fold higher than the respective IgG1 MAbs, while the IgG2 MAbs had the least activity. Against a mutant with increased fHbp expression, the anti-fHbp MAbs elicited greater C4b deposition (classical pathway) and greater bactericidal activity than against the wild-type strain, and the IgG1 MAbs had similar or greater activity than the respective IgG3 MAbs. The bactericidal activity against both wild-type and mutant strains also was dependent, in part, on activation of the alternative complement pathway. Thus, at lower epitope density in the wild-type strain, the IgG3 anti-fHbp MAbs had the greatest bactericidal activity. At a higher epitope density in the mutant, the IgG1 MAbs had similar or greater bactericidal activity than the IgG3 MAbs, and the activity was less dependent on the inhibition of fH binding than at a lower epitope density.

  14. Soluble Collectin-12 (CL-12) Is a Pattern Recognition Molecule Initiating Complement Activation via the Alternative Pathway

    DEFF Research Database (Denmark)

    Ma, Ying Jie; Hein, Estrid; Munthe-Fog, Lea

    2015-01-01

    and may recognize certain bacteria and fungi, leading to opsonophagocytosis. However, based on its structural and functional similarities with soluble collectins, we hypothesized the existence of a fluid-phase analog of CL-12 released from cells, which may function as a soluble pattern-recognition...... of the terminal complement complex. These results demonstrate the existence of CL-12 in a soluble form and indicate a novel mechanism by which the alternative pathway of complement may be triggered directly by a soluble pattern-recognition molecule....... nonreducing conditions it presented multimeric assembly forms. Immunoprecipitation and Western blot analysis of human umbilical cord plasma enabled identification of a natural soluble form of CL-12 having an electrophoretic mobility pattern close to that of shed soluble recombinant CL-12. Soluble CL-12 could...

  15. Inhibition of the alternative complement activation pathway in traumatic brain injury by a monoclonal anti-factor B antibody: a randomized placebo-controlled study in mice

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    Holers V Michael

    2007-05-01

    Full Text Available Abstract Background The posttraumatic response to traumatic brain injury (TBI is characterized, in part, by activation of the innate immune response, including the complement system. We have recently shown that mice devoid of a functional alternative pathway of complement activation (factor B-/- mice are protected from complement-mediated neuroinflammation and neuropathology after TBI. In the present study, we extrapolated this knowledge from studies in genetically engineered mice to a pharmacological approach using a monoclonal anti-factor B antibody. This neutralizing antibody represents a specific and potent inhibitor of the alternative complement pathway in mice. Methods A focal trauma was applied to the left hemisphere of C57BL/6 mice (n = 89 using a standardized electric weight-drop model. Animals were randomly assigned to two treatment groups: (1 Systemic injection of 1 mg monoclonal anti-factor B antibody (mAb 1379 in 400 μl phosphate-buffered saline (PBS at 1 hour and 24 hours after trauma; (2 Systemic injection of vehicle only (400 μl PBS, as placebo control, at identical time-points after trauma. Sham-operated and untreated mice served as additional negative controls. Evaluation of neurological scores and analysis of brain tissue specimens and serum samples was performed at defined time-points for up to 1 week. Complement activation in serum was assessed by zymosan assay and by murine C5a ELISA. Brain samples were analyzed by immunohistochemistry, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL histochemistry, and real-time RT-PCR. Results The mAb 1379 leads to a significant inhibition of alternative pathway complement activity and to significantly attenuated C5a levels in serum, as compared to head-injured placebo-treated control mice. TBI induced histomorphological signs of neuroinflammation and neuronal apoptosis in the injured brain hemisphere of placebo-treated control mice for up to 7 days. In contrast, the

  16. Functional assay of the alternative complement pathway of rat serum

    International Nuclear Information System (INIS)

    Coonrod, J.D.; Jenkins, S.D.

    1979-01-01

    Two functional assays of the alternative pathway of complement activation in rat serum were developed. In the first assay, conditions were established for titration of alternative pathway activity by use of the 50% hemolytic end-point of rabbit red blood cells (RaRBC) in serum treated with ethyleneglycol-bis-(beta-aminoethyl ether)-N, N'-tetraacetic acid (EGTA). The second assay of alternative pathway activity was based on the opsonization of heat-killed radiolabeled pneumococci of serotype 25 (Pn25). Opsonization of Pn25 was shown to proceed entirely via the alternative pathway in rat serum. There was excellent correlation between the results obtained with the RaRBC lysis test and those obtained with the opsonization test. Because of its technical simplicity, the RaRBC lysis test appeared to be the single most useful test of alternative pathway activity in rat serum. (Auth.)

  17. Activation and binding of opsonic fragments of C3 on encapsulated Cryptococcus neoformans by using an alternative complement pathway reconstituted from six isolated proteins.

    Science.gov (United States)

    Kozel, T R; Wilson, M A; Pfrommer, G S; Schlageter, A M

    1989-07-01

    Encapsulated Cryptococcus neoformans yeast cells are potent activators of the complement system. We examined the interaction of the yeast cells with an alternative complement pathway reconstituted from isolated factor D, factor B, factor H, factor I, C3, and properdin. Incubation of encapsulated cryptococci with the reconstituted pathway led to activation and binding of C3 fragments to the yeast cells that was quantitatively and qualitatively identical to that observed with normal human serum. Incubation with either normal serum or a mixture of isolated proteins led to binding of 4 x 10(7) to 5 x 10(7) C3 molecules to the yeast cells. The kinetics for activation and binding of C3 were identical, with maximum binding observed after a 20-min incubation. Immunoglobulin G was not needed for optimal activation kinetics. C3 fragments eluted from the yeast cells by treatment with hydroxylamine and subsequent analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated the presence primarily of iC3b on yeast cells incubated with either normal serum or the reconstituted pathway. Ultrastructural examination of the opsonized yeast cells showed that the cryptococcal capsule was the site for binding of C3 activated from normal serum or the reconstituted pathway, with a dense accumulation of C3 at the periphery of the capsule. Thus, incubation of encapsulated cryptococci in the reconstituted pathway led to deposition of opsonic complement fragments at a site that was appropriate for interaction with phagocyte receptors. Cryptococci opsonized with the reconstituted pathway showed a markedly enhanced interaction with cultured human monocytes compared with unopsonized yeast cells, indicating that the alternative pathway alone is opsonic for yeast cells. However, the results indicate that additional serum factors are needed for optimal opsonization of yeast cells because a 35% reduction in the number of cryptococci bound to macrophages was observed with

  18. Complement activation and inhibition: a delicate balance

    DEFF Research Database (Denmark)

    Sjöberg, A P; Trouw, L A; Blom, A M

    2009-01-01

    proteins, pentraxins, amyloid deposits, prions and DNA, all bind the complement activator C1q, but also interact with complement inhibitors C4b-binding protein and factor H. This contrasts to the interaction between C1q and immune complexes, in which case no inhibitors bind, resulting in full complement...

  19. Complement Activation in Inflammatory Skin Diseases

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    Jenny Giang

    2018-04-01

    Full Text Available The complement system is a fundamental part of the innate immune system, playing a crucial role in host defense against various pathogens, such as bacteria, viruses, and fungi. Activation of complement results in production of several molecules mediating chemotaxis, opsonization, and mast cell degranulation, which can contribute to the elimination of pathogenic organisms and inflammation. Furthermore, the complement system also has regulating properties in inflammatory and immune responses. Complement activity in diseases is rather complex and may involve both aberrant expression of complement and genetic deficiencies of complement components or regulators. The skin represents an active immune organ with complex interactions between cellular components and various mediators. Complement involvement has been associated with several skin diseases, such as psoriasis, lupus erythematosus, cutaneous vasculitis, urticaria, and bullous dermatoses. Several triggers including auto-antibodies and micro-organisms can activate complement, while on the other hand complement deficiencies can contribute to impaired immune complex clearance, leading to disease. This review provides an overview of the role of complement in inflammatory skin diseases and discusses complement factors as potential new targets for therapeutic intervention.

  20. A potent complement factor C3 specific nanobody inhibiting multiple functions in the alternative pathway of human and murine complement.

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    Jensen, Rasmus K; Pihl, Rasmus; Gadeberg, Trine A F; Jensen, Jan K; Andersen, Kasper R; Thiel, Steffen; Laursen, Nick S; Andersen, Gregers Rom

    2018-03-01

    The complement system is a complex, carefully regulated proteolytic cascade for which suppression of aberrant activation is of increasing clinical relevance and inhibition of the complement alternative pathway is a subject of intense research. Here, we describe the nanobody hC3Nb1 that binds to multiple functional states of C3 with sub-nanomolar affinity. The nanobody causes a complete shutdown of alternative pathway activity in human and murine serum when present in concentrations comparable to C3, and hC3Nb1 is shown to prevent both proconvertase assembly as well as binding of the C3 substrate to C3 convertases. Our crystal structure of the C3b-hC3Nb1 complex and functional experiments demonstrate that proconvertase formation is blocked by steric hindrance between the nanobody and an Asn-linked glycan on complement factor B. In addition, hC3Nb1 is shown to prevent factor H binding to C3b rationalizing its inhibition of factor I activity. Our results identify hC3Nb1 as a versatile, inexpensive, and powerful inhibitor of the alternative pathway in both human and murine in vitro model systems of complement activation. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Systemic complement activation in age-related macular degeneration.

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    Hendrik P N Scholl

    Full Text Available Dysregulation of the alternative pathway (AP of complement cascade has been implicated in the pathogenesis of age-related macular degeneration (AMD, the leading cause of blindness in the elderly. To further test the hypothesis that defective control of complement activation underlies AMD, parameters of complement activation in blood plasma were determined together with disease-associated genetic markers in AMD patients. Plasma concentrations of activation products C3d, Ba, C3a, C5a, SC5b-9, substrate proteins C3, C4, factor B and regulators factor H and factor D were quantified in patients (n = 112 and controls (n = 67. Subjects were analyzed for single nucleotide polymorphisms in factor H (CFH, factor B-C2 (BF-C2 and complement C3 (C3 genes which were previously found to be associated with AMD. All activation products, especially markers of chronic complement activation Ba and C3d (p<0.001, were significantly elevated in AMD patients compared to controls. Similar alterations were observed in factor D, but not in C3, C4 or factor H. Logistic regression analysis revealed better discriminative accuracy of a model that is based only on complement activation markers Ba, C3d and factor D compared to a model based on genetic markers of the complement system within our study population. In both the controls' and AMD patients' group, the protein markers of complement activation were correlated with CFH haplotypes.This study is the first to show systemic complement activation in AMD patients. This suggests that AMD is a systemic disease with local disease manifestation at the ageing macula. Furthermore, the data provide evidence for an association of systemic activation of the alternative complement pathway with genetic variants of CFH that were previously linked to AMD susceptibility.

  2. Cyclosporine Induces Endothelial Cell Release of Complement-Activating Microparticles

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    Renner, Brandon; Klawitter, Jelena; Goldberg, Ryan; McCullough, James W.; Ferreira, Viviana P.; Cooper, James E.; Christians, Uwe

    2013-01-01

    Defective control of the alternative pathway of complement is an important risk factor for several renal diseases, including atypical hemolytic uremic syndrome. Infections, drugs, pregnancy, and hemodynamic insults can trigger episodes of atypical hemolytic uremic syndrome in susceptible patients. Although the mechanisms linking these clinical events with disease flares are unknown, recent work has revealed that each of these clinical conditions causes cells to release microparticles. We hypothesized that microparticles released from injured endothelial cells promote intrarenal complement activation. Calcineurin inhibitors cause vascular and renal injury and can trigger hemolytic uremic syndrome. Here, we show that endothelial cells exposed to cyclosporine in vitro and in vivo release microparticles that activate the alternative pathway of complement. Cyclosporine-induced microparticles caused injury to bystander endothelial cells and are associated with complement-mediated injury of the kidneys and vasculature in cyclosporine-treated mice. Cyclosporine-induced microparticles did not bind factor H, an alternative pathway regulatory protein present in plasma, explaining their complement-activating phenotype. Finally, we found that in renal transplant patients, the number of endothelial microparticles in plasma increases 2 weeks after starting tacrolimus, and treatment with tacrolimus associated with increased C3 deposition on endothelial microparticles in the plasma of some patients. These results suggest that injury-associated release of endothelial microparticles is an important mechanism by which systemic insults trigger intravascular complement activation and complement-dependent renal diseases. PMID:24092930

  3. Complement activation by Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jensen, E T; Kharazmi, A; Garred, P

    1993-01-01

    In chronic infections, such as the bronchopulmonary Pseudomonas aeruginosa infection in cystic fibrosis (CF) patients, bacteria persist despite an intact host immune defense and frequent antibiotic treatment. An important reason for the persistence of the bacteria is their capacity for the biofilm...... mode of growth. In this study we investigated the role of biofilms in activation of complement, a major contributor to the inflammatory process. Complement activation by P. aeruginosa was examined in a complement consumption assay, production of C3 and factor B conversion products assessed by crossed...... immuno-electrophoresis, C5a generation tested by a PMN chemotactic assay, and terminal complement complex formation measured by ELISA. Two of the four assays showed that P. aeruginosa grown in biofilm activated complement less than planktonic bacteria, and all assays showed that activation by intact...

  4. Genetic Association of the Porcine C9 Complement Component with Hemolytic Complement Activity

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    D. V. A. Khoa

    2015-09-01

    Full Text Available The complement system is a part of the natural immune regulation mechanism against invading pathogens. Complement activation from three different pathways (classical, lectin, and alternative leads to the formation of C5-convertase, an enzyme for cleavage of C5 into C5a and C5b, followed by C6, C7, C8, and C9 in membrane attack complex. The C9 is the last complement component of the terminal lytic pathway, which plays an important role in lysis of the target cells depending on its self-polymerization to form transmembrane channels. To address the association of C9 with traits related to disease resistance, the complete porcine C9 cDNA was comparatively sequenced to detect single nucleotide polymorphisms (SNPs in pigs of the breeds Hampshire (HS, Duroc (DU, Berlin miniature pig (BMP, German Landrace (LR, Pietrain (PIE, and Muong Khuong (Vietnamese potbelly pig. Genotyping was performed in 417 F2 animals of a resource population (DUMI: DU×BMP that were vaccinated with Mycoplasma hyopneumoniae, Aujeszky diseases virus and porcine respiratory and reproductive syndrome virus at 6, 14 and 16 weeks of age, respectively. Two SNPs were detected within the third exon. One of them has an amino acid substitution. The European porcine breeds (LR and PIE show higher allele frequency of these SNPs than Vietnamese porcine breed (MK. Association of the substitution SNP with hemolytic complement activity indicated statistically significant differences between genotypes in the classical pathway but not in the alternative pathway. The interactions between eight time points of measurement of complement activity before and after vaccinations and genotypes were significantly different. The difference in hemolytic complement activity in the both pathways depends on genotype, kind of vaccine, age and the interaction to the other complement components. These results promote the porcine C9 (pC9 as a candidate gene to improve general animal health in the future.

  5. Sodium polyanethole sulfonate as an inhibitor of activation of complement function in blood culture systems

    DEFF Research Database (Denmark)

    Palarasah, Yaseelan; Skjoedt, Mikkel-Ole; Vitved, Lars

    2010-01-01

    complement activation pathways: the classical, alternative, and lectin pathways, respectively. Inhibition of complement activity by SPS is caused by a blocking of complement activation and is not a result of complement consumption. The classical pathway is inhibited at SPS concentrations greater than 0.1 mg...... findings also open up the possibility of a new assay for the assessment of the functional capacity of the lectin complement pathway....

  6. A potent complement factor C3 specific nanobody inhibiting multiple functions in the alternative pathway of human and murine complement

    DEFF Research Database (Denmark)

    Jensen, Rasmus K; Pihl, Rasmus; Gadeberg, Trine A F

    2018-01-01

    The complement system is a complex, carefully regulated proteolytic cascade for which suppression of aberrant activation is of increasing clinical relevance and inhibition of the complement alternative pathway is a subject of intense research. Here, we describe the nanobody hC3Nb1 that binds...... to multiple functional states of C3 with sub-nanomolar affinity. The nanobody causes a complete shutdown of alternative pathway activity in human and murine serum when present in concentrations comparable to C3, and hC3Nb1 is shown to prevent both proconvertase assembly as well as binding of the C3 substrate...... to C3 convertases. Our crystal structure of the C3b-hC3Nb1 complex and functional experiments demonstrate that proconvertase formation is blocked by steric hindrance between the nanobody and an Asn-linked glycan on complement factor B. In addition, hC3Nb1 is shown to prevent factor H binding to C3b...

  7. Complement receptor expression and activation of the complement cascade on B lymphocytes from patients with systemic lupus erythematosus (SLE)

    DEFF Research Database (Denmark)

    Marquart, H V; Svendsen, A; Rasmussen, J M

    1995-01-01

    It has previously been reported that the expression of the complement receptors, CR1 on erythrocytes and blood leucocytes and CR2 on B cells, is reduced in patients with SLE, and that the reduced expression of CR1 on erythrocytes is related to disease activity. We have earlier demonstrated...... that normal B cells are capable of activating the alternative pathway (AP) of complement in a CR2-dependent fashion. In this study we have investigated whether disturbances in this activity may be related to the altered phenotype of SLE B cells. Flow cytometry was used to measure expression of complement...

  8. Study of the optimal reaction conditions for assay of the mouse alternative complement pathway

    NARCIS (Netherlands)

    Dijk, H. van; Rademaker, P.M.; Klerx, J.P.A.M.; Willers, J.M.M.

    1985-01-01

    The optimal reaction conditions for hemolytic assay of alternative complement pathway activity in mouse serum were investigated. A microtiter system was used, in which a number of 7.5×106 rabbit erythrocytes per test well appeared to be optimal. Rabbit erythrocytes were superior as target cells over

  9. Micrurus snake venoms activate human complement system and generate anaphylatoxins

    Directory of Open Access Journals (Sweden)

    Tanaka Gabriela D

    2012-01-01

    Full Text Available Abstract Background The genus Micrurus, coral snakes (Serpentes, Elapidae, comprises more than 120 species and subspecies distributed from the south United States to the south of South America. Micrurus snake bites can cause death by muscle paralysis and further respiratory arrest within a few hours after envenomation. Clinical observations show mainly neurotoxic symptoms, although other biological activities have also been experimentally observed, including cardiotoxicity, hemolysis, edema and myotoxicity. Results In the present study we have investigated the action of venoms from seven species of snakes from the genus Micrurus on the complement system in in vitro studies. Several of the Micrurus species could consume the classical and/or the lectin pathways, but not the alternative pathway, and C3a, C4a and C5a were generated in sera treated with the venoms as result of this complement activation. Micrurus venoms were also able to directly cleave the α chain of the component C3, but not of the C4, which was inhibited by 1,10 Phenanthroline, suggesting the presence of a C3α chain specific metalloprotease in Micrurus spp venoms. Furthermore, complement activation was in part associated with the cleavage of C1-Inhibitor by protease(s present in the venoms, which disrupts complement activation control. Conclusion Micrurus venoms can activate the complement system, generating a significant amount of anaphylatoxins, which may assist due to their vasodilatory effects, to enhance the spreading of other venom components during the envenomation process.

  10. The Epidermal Growth Factor Receptor Is a Regulator of Epidermal Complement Component Expression and Complement Activation

    DEFF Research Database (Denmark)

    Abu-Humaidan, Anas H A; Ananthoju, Nageshwar; Mohanty, Tirthankar

    2014-01-01

    The complement system is activated in response to tissue injury. During wound healing, complement activation seems beneficial in acute wounds but may be detrimental in chronic wounds. We found that the epidermal expression of many complement components was only increased to a minor extent in skin...

  11. AMD and the alternative complement pathway: genetics and functional implications.

    Science.gov (United States)

    Tan, Perciliz L; Bowes Rickman, Catherine; Katsanis, Nicholas

    2016-06-21

    Age-related macular degeneration (AMD) is an ocular neurodegenerative disorder and is the leading cause of legal blindness in Western societies, with a prevalence of up to 8 % over the age of 60, which continues to increase with age. AMD is characterized by the progressive breakdown of the macula (the central region of the retina), resulting in the loss of central vision including visual acuity. While its molecular etiology remains unclear, advances in genetics and genomics have illuminated the genetic architecture of the disease and have generated attractive pathomechanistic hypotheses. Here, we review the genetic architecture of AMD, considering the contribution of both common and rare alleles to susceptibility, and we explore the possible mechanistic links between photoreceptor degeneration and the alternative complement pathway, a cascade that has emerged as the most potent genetic driver of this disorder.

  12. Complement activation by ceramide transporter proteins.

    Science.gov (United States)

    Bode, Gerard H; Losen, Mario; Buurman, Wim A; Veerhuis, Robert; Molenaar, Peter C; Steinbusch, Harry W M; De Baets, Marc H; Daha, Mohamed R; Martinez-Martinez, Pilar

    2014-02-01

    C1q is the initiator of the classical complement pathway and, as such, is essential for efficient opsonization and clearance of pathogens, altered self-structures, and apoptotic cells. The ceramide transporter protein (CERT) and its longer splicing isoform CERTL are known to interact with extracellular matrix components, such as type IV collagen, and with the innate immune protein serum amyloid P. In this article, we report a novel function of CERT in the innate immune response. Both CERT isoforms, when immobilized, were found to bind the globular head region of C1q and to initiate the classical complement pathway, leading to activation of C4 and C3, as well as generation of the membrane attack complex C5b-9. In addition, C1q was shown to bind to endogenous CERTL on the surface of apoptotic cells. These results demonstrate the role of CERTs in innate immunity, especially in the clearance of apoptotic cells.

  13. Peptide Inhibitor of Complement C1 (PIC1 Rapidly Inhibits Complement Activation after Intravascular Injection in Rats.

    Directory of Open Access Journals (Sweden)

    Julia A Sharp

    Full Text Available The complement system has been increasingly recognized to play a pivotal role in a variety of inflammatory and autoimmune diseases. Consequently, therapeutic modulators of the classical, lectin and alternative pathways of the complement system are currently in pre-clinical and clinical development. Our laboratory has identified a peptide that specifically inhibits the classical and lectin pathways of complement and is referred to as Peptide Inhibitor of Complement C1 (PIC1. In this study, we determined that the lead PIC1 variant demonstrates a salt-dependent binding to C1q, the initiator molecule of the classical pathway. Additionally, this peptide bound to the lectin pathway initiator molecule MBL as well as the ficolins H, M and L, suggesting a common mechanism of PIC1 inhibitory activity occurs via binding to the collagen-like tails of these collectin molecules. We further analyzed the effect of arginine and glutamic acid residue substitution on the complement inhibitory activity of our lead derivative in a hemolytic assay and found that the original sequence demonstrated superior inhibitory activity. To improve upon the solubility of the lead derivative, a pegylated, water soluble variant was developed, structurally characterized and demonstrated to inhibit complement activation in mouse plasma, as well as rat, non-human primate and human serum in vitro. After intravenous injection in rats, the pegylated derivative inhibited complement activation in the blood by 90% after 30 seconds, demonstrating extremely rapid function. Additionally, no adverse toxicological effects were observed in limited testing. Together these results show that PIC1 rapidly inhibits classical complement activation in vitro and in vivo and is functional for a variety of animal species, suggesting its utility in animal models of classical complement-mediated diseases.

  14. Complement activation in emergency department patients with severe sepsis.

    Science.gov (United States)

    Younger, John G; Bracho, David O; Chung-Esaki, Hangyul M; Lee, Moonseok; Rana, Gurpreet K; Sen, Ananda; Jones, Alan E

    2010-04-01

    This study assessed the extent and mechanism of complement activation in community-acquired sepsis at presentation to the emergency department (ED) and following 24 hours of quantitative resuscitation. A prospective pilot study of patients with severe sepsis and healthy controls was conducted among individuals presenting to a tertiary care ED. Resuscitation, including antibiotics and therapies to normalize central venous and mean arterial pressure (MAP) and central venous oxygenation, was performed on all patients. Serum levels of Factor Bb (alternative pathway), C4d (classical and mannose-binding lectin [MBL] pathway), C3, C3a, and C5a were determined at presentation and 24 hours later among patients. Twenty patients and 10 healthy volunteer controls were enrolled. Compared to volunteers, all proteins measured were abnormally higher among septic patients (C4d 3.5-fold; Factor Bb 6.1-fold; C3 0.8-fold; C3a 11.6-fold; C5a 1.8-fold). Elevations in C5a were most strongly correlated with alternative pathway activation. Surprisingly, a slight but significant inverse relationship between illness severity (by sequential organ failure assessment [SOFA] score) and C5a levels at presentation was noted. Twenty-four hours of structured resuscitation did not, on average, affect any of the mediators studied. Patients with community-acquired sepsis have extensive complement activation, particularly of the alternative pathway, at the time of presentation that was not significantly reversed by 24 hours of aggressive resuscitation.

  15. The Anticomplementary Activity of ’Fusobacterium polymorphum’ in Normal and C-4 Deficient Sources of Guinea Pig Complement.

    Science.gov (United States)

    1977-01-12

    A complement consumption assay was used to show that the anticomplementary activity of a cell wall preparation from F. polymorphum in guinea pig complement...tests with C𔃾-deficient guinea pig sera confirmed that F. polymorphum cell walls were capable of generating alternate complement pathway activity in guinea pig sera.

  16. Complement Activation by Ceramide Transporter Proteins

    NARCIS (Netherlands)

    Bode, G.H.; Losen, M.; Buurman, W.A.; Veerhuis, R.; Molenaar, P.C.; Steinbusch, H.W.M.; De Baets, M.H.; Daha, MR; Martinez-Martinez, P.

    2014-01-01

    C1q is the initiator of the classical complement pathway and, as such, is essential for efficient opsonization and clearance of pathogens, altered self-structures, and apoptotic cells. The ceramide transporter protein (CERT) and its longer splicing isoform CERTL are known to interact with

  17. The implications of alternative splicing in the ENCODE protein complement

    DEFF Research Database (Denmark)

    Tress, Michael L.; Martelli, Pier Luigi; Frankish, Adam

    2007-01-01

    suggested as one explanation for the discrepancy between the number of human genes and functional complexity. Here, we carry out a detailed study of the alternatively spliced gene products annotated in the ENCODE pilot project. We find that alternative splicing in human genes is more frequent than has...

  18. Cristina et al., Afr J Tradit Complement Altern Med. (2014) 11(4):48 ...

    African Journals Online (AJOL)

    cadewumi

    Cristina et al., Afr J Tradit Complement Altern Med. (2014) .... New data about the multiple therapeutic valences of this plant will complement the gathered knowledge about the ..... days, on sheep initially treated with 10, 5 and 2%, respectively tincture concentrations, no fed ticks were found, demonstrating the repellent.

  19. Ainooson et al., Afr J Tradit Complement Altern Med. (2012) 9(1):8 ...

    African Journals Online (AJOL)

    AJTCAM

    Ainooson et al., Afr J Tradit Complement Altern Med. (2012) ..... The authors are grateful for the technical assistance offered by Messrs Thomas Ansah, Gordon Darku and George Ofei of ... Miller, J. R. (2003). ... R. Watson and V. R. Preedy.

  20. The Role of Properdin in Zymosan- and Escherichia coli-Induced Complement Activation

    DEFF Research Database (Denmark)

    Harboe, Morten; Garred, Peter; Lindstad, Julie K

    2012-01-01

    Properdin is well known as an enhancer of the alternative complement amplification loop when C3 is activated, whereas its role as a recognition molecule of exogenous pathogen-associated molecular patterns and initiator of complement activation is less understood. We therefore studied the role...... of properdin in activation of complement in normal human serum by zymosan and various Escherichia coli strains. In ELISA, microtiter plates coated with zymosan induced efficient complement activation with deposition of C4b and terminal complement complex on the solid phase. Virtually no deposition of C4b...... cytometry was used to further explore whether properdin acts as an initial recognition molecule reacting directly with zymosan and three E. coli strains. Experiments reported by other authors were made with EGTA Mg(2+) buffer, permitting autoactivation of C3. We found inhibition by compstatin...

  1. Functional analysis of Ficolin-3 mediated complement activation

    DEFF Research Database (Denmark)

    Hein, Estrid; Honoré, Christian; Skjoedt, Mikkel-Ole

    2010-01-01

    Ficolin-3 mediated complement activation that could be applicable for research and clinical use. Bovine serum albumin (BSA) was acetylated (acBSA) and chosen as a solid phase ligand for Ficolins in microtiter wells. Binding of Ficolins on acBSA was evaluated, as was functional complement activation...... was applied to the samples that inhibited interference from the classical pathway due to the presence of anti-BSA antibodies in some sera. We describe a novel functional method for measuring complement activation mediated by Ficolin-3 in human serum up to the formation of TCC. The assay provides...

  2. Najafidoulatabad et al., Afr J Tradit Complement Altern Med. (2014 ...

    African Journals Online (AJOL)

    cadewumi

    Background: Multiple Sclerosis (MS) is a chronic and disabling disease resulting in disabilities in young and middle-aged persons. In this study, researchers explored the effect of yoga techniques on physical activities and sexual function among some Iranian women with MS. Materials and Methods: In this study, 60 Iranian ...

  3. Najafidoulatabad et al., Afr J Tradit Complement Altern Med. (2014 ...

    African Journals Online (AJOL)

    cadewumi

    researchers explored the effect of yoga techniques on physical activities and sexual ... sclerosis (MS) were placed in two equally divided control and case groups .... foot muscles, focus their attention on on the right sole and pay attention to the ...

  4. The C-type lectin of the aggrecan G3 domain activates complement.

    Directory of Open Access Journals (Sweden)

    Camilla Melin Fürst

    Full Text Available Excessive complement activation contributes to joint diseases such as rheumatoid arthritis and osteoarthritis during which cartilage proteins are fragmented and released into the synovial fluid. Some of these proteins and fragments activate complement, which may sustain inflammation. The G3 domain of large cartilage proteoglycan aggrecan interacts with other extracellular matrix proteins, fibulins and tenascins, via its C-type lectin domain (CLD and has important functions in matrix organization. Fragments containing G3 domain are released during normal aggrecan turnover, but increasingly so in disease. We now show that the aggrecan CLD part of the G3 domain activates the classical and to a lesser extent the alternative pathway of complement, via binding of C1q and C3, respectively. The complement control protein (CCP domain adjacent to the CLD showed no effect on complement initiation. The binding of C1q to G3 depended on ionic interactions and was decreased in D2267N mutant G3. However, the observed complement activation was attenuated due to binding of complement inhibitor factor H to CLD and CCP domains. This was most apparent at the level of deposition of terminal complement components. Taken together our observations indicate aggrecan CLD as one factor involved in the sustained inflammation of the joint.

  5. Anti-complement activities of human breast-milk.

    Science.gov (United States)

    Ogundele, M O

    1999-08-01

    It has long been observed that the human milk possesses significant anti-inflammatory properties, while simultaneously protecting the infant against many intestinal and respiratory pathogens. There is, however, a paucity of information on the degree and extent of this anti-inflammatory activity. In the present study, the inhibitory effects of different fractions of human milk on serum complement activity were analysed. Colostrum and milk samples from healthy voluntary lactating donors at different postpartum ages were obtained and pooled normal human serum was used as source of complement in a modified CH50 assay. Inherent complement activity in human milk was also investigated by measuring the deposition of an activated C3 fragment on a serum-sensitive bacteria, and by haemolytic assays. Most whole- and defatted-milk samples consistently showed a dose-dependent inhibition of the serum complement activity. This inhibition was greater in mature milk compared to transitional milk samples. It was enhanced by inactivation of milk complement, and diminished by centrifugation of milk samples, which partly removed fat and larger protein components including casein micelles. Inherent complement activity in human milk was also demonstrated by haemolysis of sensitised sheep erythrocytes and deposition of C3 fragments on solid-phase bacteria. These activities were highest in the colostrum and gradually decreased as lactation proceeded. Several natural components abundant in the fluid phase of the human breast-milk have been shown to be inhibitors of complement activation in vitro. Their physiological significance probably reside in their ability to prevent inflammatory-induced tissue damage of the delicate immature gastrointestinal tract of the new-born as well as the mammary gland itself, which may arise from ongoing complement activation.

  6. Complement is activated in progressive multiple sclerosis cortical grey matter lesions.

    Science.gov (United States)

    Watkins, Lewis M; Neal, James W; Loveless, Sam; Michailidou, Iliana; Ramaglia, Valeria; Rees, Mark I; Reynolds, Richard; Robertson, Neil P; Morgan, B Paul; Howell, Owain W

    2016-06-22

    The symptoms of multiple sclerosis (MS) are caused by damage to myelin and nerve cells in the brain and spinal cord. Inflammation is tightly linked with neurodegeneration, and it is the accumulation of neurodegeneration that underlies increasing neurological disability in progressive MS. Determining pathological mechanisms at play in MS grey matter is therefore a key to our understanding of disease progression. We analysed complement expression and activation by immunocytochemistry and in situ hybridisation in frozen or formalin-fixed paraffin-embedded post-mortem tissue blocks from 22 progressive MS cases and made comparisons to inflammatory central nervous system disease and non-neurological disease controls. Expression of the transcript for C1qA was noted in neurons and the activation fragment and opsonin C3b-labelled neurons and glia in the MS cortical and deep grey matter. The density of immunostained cells positive for the classical complement pathway protein C1q and the alternative complement pathway activation fragment Bb was significantly increased in cortical grey matter lesions in comparison to control grey matter. The number of cells immunostained for the membrane attack complex was elevated in cortical lesions, indicating complement activation to completion. The numbers of classical (C1-inhibitor) and alternative (factor H) pathway regulator-positive cells were unchanged between MS and controls, whilst complement anaphylatoxin receptor-bearing microglia in the MS cortex were found closely apposed to cortical neurons. Complement immunopositive neurons displayed an altered nuclear morphology, indicative of cell stress/damage, supporting our finding of significant neurodegeneration in cortical grey matter lesions. Complement is activated in the MS cortical grey matter lesions in areas of elevated numbers of complement receptor-positive microglia and suggests that complement over-activation may contribute to the worsening pathology that underlies the

  7. Pseudomonas aeruginosa alkaline protease blocks complement activation via the classical and lectin pathways.

    Science.gov (United States)

    Laarman, Alexander J; Bardoel, Bart W; Ruyken, Maartje; Fernie, Job; Milder, Fin J; van Strijp, Jos A G; Rooijakkers, Suzan H M

    2012-01-01

    The complement system rapidly detects and kills Gram-negative bacteria and supports bacterial killing by phagocytes. However, bacterial pathogens exploit several strategies to evade detection by the complement system. The alkaline protease (AprA) of Pseudomonas aeruginosa has been associated with bacterial virulence and is known to interfere with complement-mediated lysis of erythrocytes, but its exact role in bacterial complement escape is unknown. In this study, we analyzed how AprA interferes with complement activation and whether it could block complement-dependent neutrophil functions. We found that AprA potently blocked phagocytosis and killing of Pseudomonas by human neutrophils. Furthermore, AprA inhibited opsonization of bacteria with C3b and the formation of the chemotactic agent C5a. AprA specifically blocked C3b deposition via the classical and lectin pathways, whereas the alternative pathway was not affected. Serum degradation assays revealed that AprA degrades both human C1s and C2. However, repletion assays demonstrated that the mechanism of action for complement inhibition is cleavage of C2. In summary, we showed that P. aeruginosa AprA interferes with classical and lectin pathway-mediated complement activation via cleavage of C2.

  8. Acidosis activates complement system in vitro.

    OpenAIRE

    Emeis, M; Sonntag, J; Willam, C; Strauss, E; Walka, M M; Obladen, M

    1998-01-01

    We investigated the in vitro effect of different forms of acidosis (pH 7.0) on the formation of anaphylatoxins C3a and C5a. Metabolic acidosis due to addition of hydrochloric acid (10 micromol/ml blood) or lactic acid (5.5 micromol/ml) to heparin blood (N=12) caused significant activation of C3a and C5a compared to control (both p=0.002). Respiratory acidosis activated C3a (p=0.007) and C5a (p=0.003) compared to normocapnic controls. Making blood samples with lactic acidosis hypocapnic result...

  9. Anopheles Midgut Epithelium Evades Human Complement Activity by Capturing Factor H from the Blood Meal

    Science.gov (United States)

    Khattab, Ayman; Barroso, Marta; Miettinen, Tiera; Meri, Seppo

    2015-01-01

    Hematophagous vectors strictly require ingesting blood from their hosts to complete their life cycles. Exposure of the alimentary canal of these vectors to the host immune effectors necessitates efficient counteractive measures by hematophagous vectors. The Anopheles mosquito transmitting the malaria parasite is an example of hematophagous vectors that within seconds can ingest human blood double its weight. The innate immune defense mechanisms, like the complement system, in the human blood should thereby immediately react against foreign cells in the mosquito midgut. A prerequisite for complement activation is that the target cells lack complement regulators on their surfaces. In this work, we analyzed whether human complement is active in the mosquito midgut, and how the mosquito midgut cells protect themselves against complement attack. We found that complement remained active for a considerable time and was able to kill microbes within the mosquito midgut. However, the Anopheles mosquito midgut cells were not injured. These cells were found to protect themselves by capturing factor H, the main soluble inhibitor of the alternative complement pathway. Factor H inhibited complement on the midgut cells by promoting inactivation of C3b to iC3b and preventing the activity of the alternative pathway amplification C3 convertase enzyme. An interference of the FH regulatory activity by monoclonal antibodies, carried to the midgut via blood, resulted in increased mosquito mortality and reduced fecundity. By using a ligand blotting assay, a putative mosquito midgut FH receptor could be detected. Thereby, we have identified a novel mechanism whereby mosquitoes can tolerate human blood. PMID:25679788

  10. Anopheles midgut epithelium evades human complement activity by capturing factor H from the blood meal.

    Directory of Open Access Journals (Sweden)

    Ayman Khattab

    2015-02-01

    Full Text Available Hematophagous vectors strictly require ingesting blood from their hosts to complete their life cycles. Exposure of the alimentary canal of these vectors to the host immune effectors necessitates efficient counteractive measures by hematophagous vectors. The Anopheles mosquito transmitting the malaria parasite is an example of hematophagous vectors that within seconds can ingest human blood double its weight. The innate immune defense mechanisms, like the complement system, in the human blood should thereby immediately react against foreign cells in the mosquito midgut. A prerequisite for complement activation is that the target cells lack complement regulators on their surfaces. In this work, we analyzed whether human complement is active in the mosquito midgut, and how the mosquito midgut cells protect themselves against complement attack. We found that complement remained active for a considerable time and was able to kill microbes within the mosquito midgut. However, the Anopheles mosquito midgut cells were not injured. These cells were found to protect themselves by capturing factor H, the main soluble inhibitor of the alternative complement pathway. Factor H inhibited complement on the midgut cells by promoting inactivation of C3b to iC3b and preventing the activity of the alternative pathway amplification C3 convertase enzyme. An interference of the FH regulatory activity by monoclonal antibodies, carried to the midgut via blood, resulted in increased mosquito mortality and reduced fecundity. By using a ligand blotting assay, a putative mosquito midgut FH receptor could be detected. Thereby, we have identified a novel mechanism whereby mosquitoes can tolerate human blood.

  11. Jokar et al., Afr J Tradit Complement Altern Med. (2016) 13(1):40-44 ...

    African Journals Online (AJOL)

    PROF ADEWUNMI

    Jokar et al., Afr J Tradit Complement Altern Med. ... Shiraz- Iran.3Department of Obstetrics and Gynecology, School of Medicine and maternal- fetal ..... Ann Intern Med 2001; 135(5):344–51. 7. ... Clin Geriatr Med.2008; ... Indian J. Med Res.

  12. Mnengi et al., Afr J Tradit Complement Altern Med. (2014) 11(4):62 ...

    African Journals Online (AJOL)

    cadewumi

    Mnengi et al., Afr J Tradit Complement Altern Med. (2014) 11(4):62-65 ... A drop of dry yeast suspension was added as food to each vial. Probit analysis ... of five while some children are treated with malaria medications in biomedical facilities, as the World Health Organization recommends, others obtain home-care or ...

  13. Yadav et al., Afr J Tradit Complement Altern Med. (2014) 11(2):249 ...

    African Journals Online (AJOL)

    cadewumi

    Yadav et al., Afr J Tradit Complement Altern Med. (2014) 11(2):249-256 ..... In recent years the popularity of complementary medicine has increased. Much interest has been focused on exploring ... delayed the induction of glucose intolerance and euglycemia in high fructose diet fed rats. Diabegon treatment inhibits the ...

  14. Al-muammar et al., Afr J Tradit Complement Altern Med. (2016) 13(1 ...

    African Journals Online (AJOL)

    PROF ADEWUNMI

    Al-muammar et al., Afr J Tradit Complement Altern Med. (2016) 13(1):17- .... Feed and water were provided ad libitum for one week before the start of experiment for adaptation. The basal .... The mean value of feed intake (g/day/rat) for all treated groups was slightly reduced as compared to the negative control group. On the.

  15. Ahn and Son Afr J Tradit Complement Altern Med. (2014) 11(1):28 ...

    African Journals Online (AJOL)

    cadewumi

    Ahn and Son Afr J Tradit Complement Altern Med. (2014) 11(1):28-29 ... The comparisons of the frequency and choice of functional supplements were analysed using Chi-square test with. SPSS (SPSSs 18.0K for ... Significant difference of choice for functional supplements was observed between male and female (p < 0.01) ...

  16. Sun et al., Afr J Tradit Complement Altern Med. (2011) 8(3):224-229

    African Journals Online (AJOL)

    AJTCAM

    Sun et al., Afr J Tradit Complement Altern Med. (2011) 8(3):224-229. 224. EFFECTS OF CHINESE MATERIA MEDICA-FUBAO DANGGUI JIAO ON EXPERIMENTAL. ENDOMETRIOSIS. Xing Sun*, Master; Lijue Chen, Master; Fanbo Zeng1,. Department of Pharmacy, Tongji Medical College, Huazhong. University of Science ...

  17. Complement-coagulation cross-talk: a potential mediator of the physiological activation of complement by low pH

    Directory of Open Access Journals (Sweden)

    Hany Ibrahim Kenawy

    2015-05-01

    Full Text Available The complement system is a major constituent of the innate immune system. It not only bridges innate and adaptive arms of the immune system but also links the immune system with the coagulation system. Current understanding of the role of complement has extended far beyond fighting of infections, and now encompasses maintenance of homeostasis, tissue regeneration and pathophysiology of multiple diseases. It has been known for many years that complement activation is strongly pH sensitive, but only relatively recently has the physiological significance of this been appreciated. Most complement assays are carried out at the physiological pH 7.4. However, pH in some extracellular compartments, for example renal tubular fluid in parts of the tubule, and extracellular fluid at inflammation loci, is sufficiently acidic to activate complement. The exact molecular mechanism of this activation is still unclear, but possible cross talk between the contact system and complement may exist at low pH with subsequent complement activation. The current article reviews the published data on the effect of pH on the contact system and complement activity, the nature of the pH sensor molecules, and the clinical implications of these effects. Of particular interest is chronic kidney disease (CKD accompanied by metabolic acidosis, in which therapeutic alkalinisation of urine has been shown significantly to reduce tubular complement activation products, an effect which may have important implications for slowing progression of CKD.

  18. Complement activation in leprosy: a retrospective study shows elevated circulating terminal complement complex in reactional leprosy.

    Science.gov (United States)

    Bahia El Idrissi, N; Hakobyan, S; Ramaglia, V; Geluk, A; Morgan, B Paul; Das, P Kumar; Baas, F

    2016-06-01

    Mycobacterium leprae infection gives rise to the immunologically and histopathologically classified spectrum of leprosy. At present, several tools for the stratification of patients are based on acquired immunity markers. However, the role of innate immunity, particularly the complement system, is largely unexplored. The present retrospective study was undertaken to explore whether the systemic levels of complement activation components and regulators can stratify leprosy patients, particularly in reference to the reactional state of the disease. Serum samples from two cohorts were analysed. The cohort from Bangladesh included multi-bacillary (MB) patients with (n = 12) or without (n = 46) reaction (R) at intake and endemic controls (n = 20). The cohort from Ethiopia included pauci-bacillary (PB) (n = 7) and MB (n = 23) patients without reaction and MB (n = 15) patients with reaction. The results showed that the activation products terminal complement complex (TCC) (P ≤ 0·01), C4d (P ≤ 0·05) and iC3b (P ≤ 0·05) were specifically elevated in Bangladeshi patients with reaction at intake compared to endemic controls. In addition, levels of the regulator clusterin (P ≤ 0·001 without R; P < 0·05 with R) were also elevated in MB patients, irrespective of a reaction. Similar analysis of the Ethiopian cohort confirmed that, irrespective of a reaction, serum TCC levels were increased significantly in patients with reactions compared to patients without reactions (P ≤ 0·05). Our findings suggests that serum TCC levels may prove to be a valuable tool in diagnosing patients at risk of developing reactions. © 2016 British Society for Immunology.

  19. New perspectives on mannan-binding lectin-mediated complement activation

    DEFF Research Database (Denmark)

    Degn, Søren Egedal; Thiel, Steffen; Jensenius, Jens Christian

    2007-01-01

    The complement system is an important part of the innate immune system, mediating several major effector functions and modulating adaptive immune responses. Three complement activation pathways exist: the classical pathway (CP), the alternative pathway (AP), and the lectin pathway (LP). The LP......, allowing C3 activation in the absence of components otherwise believed critical. The classical bypass pathways are dependent on C1 and components of the AP. A recent study has shown the existence also of a lectin bypass pathway dependent on mannan-binding lectin (MBL) and AP components. The emerging...

  20. Functional analysis of Ficolin-3 mediated complement activation

    DEFF Research Database (Denmark)

    Hein, Estrid; Honoré, Christian Le Fèvre; Skjoedt, Mikkel-Ole

    2010-01-01

    assessed by C4, C3 and terminal complement complex (TCC) deposition. Serum Ficolin-3 bound to acBSA in a calcium dependent manner, while only minimal binding of Ficolin-2 and no binding of Ficolin-1 were observed. No binding to normal BSA was seen for any of the Ficolins. Serum C4, C3 and TCC deposition...... was applied to the samples that inhibited interference from the classical pathway due to the presence of anti-BSA antibodies in some sera. We describe a novel functional method for measuring complement activation mediated by Ficolin-3 in human serum up to the formation of TCC. The assay provides...

  1. Activation of the lectin complement pathway on human renal ...

    African Journals Online (AJOL)

    This study aimed to investigate the roles of high glucose and mannose-binding lectin (MBL) on the activation of the lectin complement pathway (LCP) on human renal glomerular endothelial cells (HRGECs) in vitro. Flow cytometry analysis, immunofluorescence staining and Western blot were used to detect the cell surface ...

  2. Complement activation in Ghanaian children with severe Plasmodium falciparum malaria

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    Ofori Michael F

    2007-12-01

    Full Text Available Abstract Background Severe anaemia (SA, intravascular haemolysis (IVH and respiratory distress (RD are severe forms of Plasmodium falciparum malaria, with RD reported to be of prognostic importance in African children with malarial anaemia. Complement factors have been implicated in the mechanism leading to excess anaemia in acute P. falciparum infection. Methods The direct Coombs test (DCT and flow cytometry were used to investigate the mean levels of RBC-bound complement fragments (C3d and C3bαβ and the regulatory proteins [complement receptor 1 (CD35 and decay accelerating factor (CD55] in children with discrete clinical forms of P. falciparum malaria. The relationship between the findings and clinical parameters including coma, haemoglobin (Hb levels and RD were investigated. Results Of the 484 samples tested, 131(27% were positive in DCT, out of which 115/131 (87.8% were positive for C3d alone while 16/131 (12.2% were positive for either IgG alone or both. 67.4% of the study population were below 5 years of age and DCT positivity was more common in this age group relative to children who were 5 years or older (Odds ratio, OR = 3.8; 95%CI, 2.2–6.7, p Conclusion These results suggest that complement activation contributed to anaemia in acute childhood P. falciparum malaria, possibly through induction of erythrophagocytosis and haemolysis. In contrast to other studies, this study did not find association between levels of the complement regulatory proteins, CD35 and CD55 and malarial anaemia. These findings suggest that complement activation could also be involved in the pathogenesis of RD but larger studies are needed to confirm this finding.

  3. Characterization of the third component of complement (C3) after activation by cigarette smoke

    International Nuclear Information System (INIS)

    Kew, R.R.; Ghebrehiwet, B.; Janoff, A.

    1987-01-01

    Activation of lung complement by tobacco smoke may be an important pathogenetic factor in the development of pulmonary emphysema in smokers. We previously showed that cigarette smoke can modify C3 and activate the alternative pathway of complement in vitro. However, the mechanism of C3 activation was not fully delineated in these earlier studies. In the present report, we show that smoke-treated C3 induces cleavage of the alternative pathway protein, Factor B, when added to serum containing Mg-EGTA. This effect of cigarette smoke is specific for C3 since smoke-treated C4, when added to Mg-EGTA-treated serum, fails to activate the alternative pathway and fails to induce Factor B cleavage. Smoke-modified C3 no longer binds significant amounts of [ 14 C]methylamine (as does native C3), and relatively little [ 14 C]methylamine is incorporated into its alpha-chain. Thus, prior internal thiolester bond cleavage appears to have occurred in C3 activated by cigarette smoke. Cigarette smoke components also induce formation of noncovalently associated, soluble C3 multimers, with a Mr ranging from 1 to 10 million. However, prior cleavage of the thiolester bond in C3 with methylamine prevents the subsequent formation of these smoke-induced aggregates. These data indicate that cigarette smoke activates the alternative pathway of complement by specifically modifying C3 and that these modifications include cleavage of the thiolester bond in C3 and formation of noncovalently linked C3 multimers

  4. The Murine Factor H-Related Protein FHR-B Promotes Complement Activation

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    Marcell Cserhalmi

    2017-09-01

    Full Text Available Factor H-related (FHR proteins consist of varying number of complement control protein domains that display various degrees of sequence identity to respective domains of the alternative pathway complement inhibitor factor H (FH. While such FHR proteins are described in several species, only human FHRs were functionally investigated. Their biological role is still poorly understood and in part controversial. Recent studies on some of the human FHRs strongly suggest a role for FHRs in enhancing complement activation via competing with FH for binding to certain ligands and surfaces. The aim of the current study was the functional characterization of a murine FHR, FHR-B. To this end, FHR-B was expressed in recombinant form. Recombinant FHR-B bound to human C3b and was able to compete with human FH for C3b binding. FHR-B supported the assembly of functionally active C3bBb alternative pathway C3 convertase via its interaction with C3b. This activity was confirmed by demonstrating C3 activation in murine serum. In addition, FHR-B bound to murine pentraxin 3 (PTX3, and this interaction resulted in murine C3 fragment deposition due to enhanced complement activation in mouse serum. FHR-B also induced C3 deposition on C-reactive protein, the extracellular matrix (ECM extract Matrigel, and endothelial cell-derived ECM when exposed to mouse serum. Moreover, mouse C3 deposition was strongly enhanced on necrotic Jurkat T cells and the mouse B cell line A20 by FHR-B. FHR-B also induced lysis of sheep erythrocytes when incubated in mouse serum with FHR-B added in excess. Altogether, these data demonstrate that, similar to human FHR-1 and FHR-5, mouse FHR-B modulates complement activity by promoting complement activation via interaction with C3b and via competition with murine FH.

  5. M. leprae components induce nerve damage by complement activation: identification of lipoarabinomannan as the dominant complement activator.

    Science.gov (United States)

    Bahia El Idrissi, Nawal; Das, Pranab K; Fluiter, Kees; Rosa, Patricia S; Vreijling, Jeroen; Troost, Dirk; Morgan, B Paul; Baas, Frank; Ramaglia, Valeria

    2015-05-01

    Peripheral nerve damage is the hallmark of leprosy pathology but its etiology is unclear. We previously identified the membrane attack complex (MAC) of the complement system as a key determinant of post-traumatic nerve damage and demonstrated that its inhibition is neuroprotective. Here, we determined the contribution of the MAC to nerve damage caused by Mycobacterium leprae and its components in mouse. Furthermore, we studied the association between MAC and the key M. leprae component lipoarabinomannan (LAM) in nerve biopsies of leprosy patients. Intraneural injections of M. leprae sonicate induced MAC deposition and pathological changes in the mouse nerve, whereas MAC inhibition preserved myelin and axons. Complement activation occurred mainly via the lectin pathway and the principal activator was LAM. In leprosy nerves, the extent of LAM and MAC immunoreactivity was robust and significantly higher in multibacillary compared to paucibacillary donors (p = 0.01 and p = 0.001, respectively), with a highly significant association between LAM and MAC in the diseased samples (r = 0.9601, p = 0.0001). Further, MAC co-localized with LAM on axons, pointing to a role for this M. leprae antigen in complement activation and nerve damage in leprosy. Our findings demonstrate that MAC contributes to nerve damage in a model of M. leprae-induced nerve injury and its inhibition is neuroprotective. In addition, our data identified LAM as the key pathogen associated molecule that activates complement and causes nerve damage. Taken together our data imply an important role of complement in nerve damage in leprosy and may inform the development of novel therapeutics for patients.

  6. Ulex europaeus agglutinin II (UEA-II) is a novel, potent inhibitor of complement activation.

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    Lekowski, R; Collard, C D; Reenstra, W R; Stahl, G L

    2001-02-01

    Complement is an important mediator of vascular injury following oxidative stress. We recently demonstrated that complement activation following endothelial oxidative stress is mediated by mannose-binding lectin (MBL) and activation of the lectin complement pathway. Here, we investigated whether nine plant lectins which have a binding profile similar to that of MBL competitively inhibit MBL deposition and subsequent complement activation following human umbilical vein endothelial cell (HUVEC) oxidative stress. HUVEC oxidative stress (1% O(2), 24 hr) significantly increased Ulex europaeus agglutinin II (UEA-II) binding by 72 +/- 9% compared to normoxic cells. UEA-II inhibited MBL binding to HUVEC in a concentration-dependent manner following oxidative stress. Further, MBL inhibited UEA-II binding to HUVEC in a concentration-dependent manner following oxidative stress, suggesting a common ligand. UEA-II (< or = 100 micromol/L) did not attenuate the hemolytic activity, nor did it inhibit C3a des Arg formation from alternative or classical complement pathway-specific hemolytic assays. C3 deposition (measured by ELISA) following HUVEC oxidative stress was inhibited by UEA-II in a concentration-dependent manner (IC(50) = 10 pmol/L). UEA-II inhibited C3 and MBL co-localization (confocal microscopy) in a concentration-dependent manner on HUVEC following oxidative stress (IC(50) approximately 1 pmol/L). Finally, UEA-II significantly inhibited complement-dependent neutrophil chemotaxis, but failed to inhibit fMLP-mediated chemotaxis, following endothelial oxidative stress. These data demonstrate that UEA-II is a novel, potent inhibitor of human MBL deposition and complement activation following human endothelial oxidative stress.

  7. Activation of the lectin pathway of complement in experimental human keratitis with Pseudomonas aeruginosa.

    Science.gov (United States)

    Osthoff, Michael; Brown, Karl D; Kong, David C M; Daniell, Mark; Eisen, Damon P

    2014-01-01

    Pseudomonas aeruginosa (P. aeruginosa) microbial keratitis (MK) is a sight-threatening disease. Previous animal studies have identified an important contribution of the complement system to the clearance of P. aeruginosa infection of the cornea. Mannose-binding lectin (MBL), a pattern recognition receptor of the lectin pathway of complement, has been implicated in the host defense against P. aeruginosa. However, studies addressing the role of the lectin pathway in P. aeruginosa MK are lacking. Hence, we sought to determine the activity of the lectin pathway in human MK caused by P. aeruginosa. Primary human corneal epithelial cells (HCECs) from cadaveric donors were exposed to two different P. aeruginosa strains. Gene expression of interleukin (IL)-6, IL-8, MBL, and other complement proteins was determined by reverse transcription-polymerase chain reaction (RT-PCR) and MBL synthesis by enzyme-linked immunosorbent assay and intracellular flow cytometry. MBL gene expression was not detected in unchallenged HCECs. Exposure of HCECs to P. aeruginosa resulted in rapid induction of the transcriptional expression of MBL, IL-6, and IL-8. In addition, expression of several complement proteins of the classical and lectin pathways, but not the alternative pathway, were upregulated after 5 h of challenge, including MBL-associated serine protease 1. However, MBL protein secretion was not detectable 18 h after challenge with P. aeruginosa. MK due to P. aeruginosa triggers activation of MBL and the lectin pathway of complement. However, the physiologic relevance of this finding is unclear, as corresponding MBL oligomer production was not observed.

  8. The alternative complement pathway control protein H binds to immune complexes and serves their detection

    International Nuclear Information System (INIS)

    Nydegger, U.E.; Corvetta, A.; Spaeth, P.J.; Spycher, M.

    1983-01-01

    During solubilization of immune complexes C3b becomes fixed to the immunoglobulin part and serves as a receptor for the alternative complement pathway control protein H. The H-C3b immune complex interaction can be made detectable using 4% polyethyleneglycol to separate free from bound 125 I-H. Tetanus toxoid (Te)/anti-Te complexes kept soluble with fresh serum and containing 125 IU of specific antibody bound 18% of 125 I-H; when fresh serum was chelated with 10 mM EDTA, 125 I-H binding was only 5%. On sucrose density gradients, the H-binding material sedimented in the range of 12 to 30 S. In 36 serum samples from rheumatoid arthritis (RA) patients and in 12 serum samples from patients with systemic lupus erythematosus (SLE), 125 I-H binding was significantly elevated to 9.5 +/- 4.7% (mean +/- 1 SD) and 13.3 +/- 5.6%, respectively, while 125 I-H binding by 36 normal human sera was 4 +/- 2%. RA samples (17/36, 47%) and SLE samples (9/12, 75%) had H-binding values increased by more than 2 SD above the normal mean. The serum samples were also assessed for conglutinin- and C1q-binding activities; a significant correlation between H and C1q binding was observed (P less than 0.001); there was no correlation between H and conglutinin binding. Although binding to immune complexes through its interaction with C3b, H clearly detects a population of complexes other than conglutinin, thus expanding the possibilities of further characterizing pathological complexes

  9. Early Intra-Articular Complement Activation in Ankle Fractures

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    Hagen Schmal

    2014-01-01

    Full Text Available Cytokine regulation possibly influences long term outcome following ankle fractures, but little is known about synovial fracture biochemistry. Eight patients with an ankle dislocation fracture were included in a prospective case series and matched with patients suffering from grade 2 osteochondritis dissecans (OCD of the ankle. All fractures needed external fixation during which joint effusions were collected. Fluid analysis was done by ELISA measuring aggrecan, bFGF, IL-1β, IGF-1, and the complement components C3a, C5a, and C5b-9. The time periods between occurrence of fracture and collection of effusion were only significantly associated with synovial aggrecan and C5b-9 levels (P<0.001. Furthermore, synovial expressions of both proteins correlated with each other (P<0.001. Although IL-1β expression was relatively low, intra-articular levels correlated with C5a (P<0.01 and serological C-reactive protein concentrations 2 days after surgery (P<0.05. Joint effusions were initially dominated by neutrophils, but the portion of monocytes constantly increased reaching 50% at day 6 after fracture (P<0.02. Whereas aggrecan and IL-1β concentrations were not different in fracture and OCD patients, bFGF, IGF-1, and all complement components were significantly higher concentrated in ankle joints with fractures (P<0.01. Complement activation and inflammatory cell infiltration characterize the joint biology following acute ankle fractures.

  10. The lectin pathway of complement activation is a critical component of the innate immune response to pneumococcal infection

    DEFF Research Database (Denmark)

    Ali, Youssif M; Lynch, Nicholas J; Haleem, Kashif S

    2012-01-01

    The complement system plays a key role in host defense against pneumococcal infection. Three different pathways, the classical, alternative and lectin pathways, mediate complement activation. While there is limited information available on the roles of the classical and the alternative activation...... to pneumococcal infection and fail to opsonize Streptococcus pneumoniae in the none-immune host. This defect in complement opsonisation severely compromises pathogen clearance in the lectin pathway deficient host. Using sera from mice and humans with defined complement deficiencies, we demonstrate that mouse...... of C4. This study corroborates the essential function of MASP-2 in the lectin pathway and highlights the importance of MBL-independent lectin pathway activation in the host defense against pneumococci....

  11. Complement activation, endothelial dysfunction, insulin resistance and chronic heart failure

    DEFF Research Database (Denmark)

    Bjerre, M.; Kistorp, C.; Hansen, T.K.

    2010-01-01

    Objectives. Patients with chronic heart failure (CHF) have an exaggerated immune response, endothelial damage/dysfunction, and increased risk of diabetes mellitus (DM). The inter-relationship(s) between indices of complement activation (soluble membrane attack complex, sMAC), inflammation (hs...... to ischemic heart disease (IHD) as compared with CHF patients with non-ischemic ethiology (p = 0.02), but were not predictive of survival or progression of CHF. A moderate strong relation between sMAC and sEsel levels was found beta = 0.33 (p ... damaging of the heart tissue...

  12. Guinea pig complement potently measures vibriocidal activity of human antibodies in response to cholera vaccines.

    Science.gov (United States)

    Kim, Kyoung Whun; Jeong, Soyoung; Ahn, Ki Bum; Yang, Jae Seung; Yun, Cheol-Heui; Han, Seung Hyun

    2017-12-01

    The vibriocidal assay using guinea pig complement is widely used for the evaluation of immune responses to cholera vaccines in human clinical trials. However, it is unclear why guinea pig complement has been used over human complement in the measurement of vibriocidal activity of human sera and there have not been comparison studies for the use of guinea pig complement over those from other species. Therefore, we comparatively investigated the effects of complements derived from human, guinea pig, rabbit, and sheep on vibriocidal activity. Complements from guinea pig, rabbit, and human showed concentration-dependent vibriocidal activity in the presence of quality control serum antibodies. Of these complements, guinea pig complement was the most sensitive and effective over a wide concentration range. When the vibriocidal activity of complements was measured in the absence of serum antibodies, human, sheep, and guinea pig complements showed vibriocidal activity up to 40-fold, 20-fold, and 1-fold dilution, respectively. For human pre- and post-vaccination sera, the most potent vibriocidal activity was observed when guinea pig complement was used. In addition, the highest fold-increases between pre- and post- vaccinated sera were obtained with guinea pig complement. Furthermore, human complement contained a higher amount of V. cholerae- and its lipopolysaccharide-specific antibodies than guinea pig complement. Collectively, these results suggest that guinea pig complements are suitable for vibriocidal assays due to their high sensitivity and effectiveness to human sera.

  13. Modulation of post-stroke degenerative and regenerative processes and subacute protection by site-targeted inhibition of the alternative pathway of complement.

    Science.gov (United States)

    Alawieh, Ali; Elvington, Andrew; Zhu, Hong; Yu, Jin; Kindy, Mark S; Atkinson, Carl; Tomlinson, Stephen

    2015-12-30

    Complement promotes neuroinflammation and injury in models of stroke. However, complement is also being increasingly implicated in repair and regeneration after central nervous system (CNS) injury, and some complement deficiencies have been shown to provide acute, but not subacute, protection after murine stroke. Here, we investigate the dual role of complement in injury and repair after cerebral ischemia and reperfusion. We used complement-deficient mice and different complement inhibitors in a model of transient middle cerebral artery occlusion to investigate complement-dependent cellular and molecular changes that occur through the subacute phase after stroke. C3 deficiency and site-targeted complement inhibition with either CR2-Crry (inhibits all pathways) or CR2-fH (inhibits alternative pathway) significantly reduced infarct size, reduced apoptotic cell death, and improved neurological deficit score in the acute phase after stroke. However, only in CR2-fH-treated mice was there sustained protection with no evolution of injury in the subacute phase. Whereas both inhibitors significantly reduced microglia/macrophage activation and astrogliosis in the subacute phase, only CR2-fH improved neurological deficit and locomotor function, maintained neurogenesis markers, enhanced neuronal migration, and increased VEGF expression. These findings in CR2-fH-treated mice correlated with improved performance in spatial learning and passive avoidance tasks. The complement anaphylatoxins have been implicated in repair and regenerative mechanisms after CNS injury, and in this context CR2-fH significantly reduced, but did not eliminate the generation of C5a within the brain, unlike CR2-Crry that completely blocked C5a generation. Gene expression profiling revealed that CR2-fH treatment downregulated genes associated with apoptosis, TGFβ signaling, and neutrophil activation, and decreased neutrophil infiltration was confirmed by immunohistochemistry. CR2-fH upregulated genes for

  14. IgG4 anti-phospholipase A2 receptor might activate lectin and alternative complement pathway meanwhile in idiopathic membranous nephropathy: an inspiration from a cross-sectional study.

    Science.gov (United States)

    Yang, Yang; Wang, Chao; Jin, Liping; He, Fagui; Li, Changchun; Gao, Qingman; Chen, Guanglei; He, Zhijun; Song, Minghui; Zhou, Zhuliang; Shan, Fujun; Qi, Ka; Ma, Lu

    2016-08-01

    The deposition of IgG4 of antibodies against phospholipase A2 receptor (anti-PLA2R) is predominating in the kidneys of patients with idiopathic membranous nephropathy, while its predictive value has not been determined. It was a retrospective study, and 438 patients were included. Serum samples of two time points [before intervention (baseline) and after 1.5-year treatment (endpoint)] were detected for total and IgG4 anti-PLA2R. IgG4 IgG4 subclass and the achievement of CR; (3) bi-negativity of IgG4 has a high accuracy of predicting CR compared with total antibodies; (4) in patients of bi-positivity, those achieving CR showed lower MASP-1/2, MBL, C3a, C5a, FB, Ba and Bb than patients failing to achieve CR; (5) the titers of endpoint and decrease in Ba and Bb were associated with improvement of 24 h-UP in those of bi-positivity; and (6) the decrease in Ba was a significant factor for achieving CR in those of bi-positivity. Continuous IgG4 negativity was a useful tool to predict the achievement of CR; however, in patients of continuous IgG4 positivity, those with lower activation of lectin and alternative pathways would still more probably achieve CR.

  15. Effect of dialyzer geometry on granulocyte and complement activation.

    Science.gov (United States)

    Schaefer, R M; Heidland, A; Hörl, W H

    1987-01-01

    During hemodialysis with cuprophan membranes, the complement system as well as leukocytes become activated. In order to clarify the role of dialyzer geometry, the effect of hollow-fiber versus flat-sheet dialyzers and of different surface areas on C3a generation and leukocyte degranulation was investigated. Plasma levels of leukocyte elastase in complex with alpha 1-proteinase inhibitor were significantly increased after 1 h (+55%) and 3 h (+62%) of hemodialysis with flat-sheet dialyzers as compared to hollow-fiber devices. In addition, plasma levels of lactoferrin, released from the specific granules of leukocytes during activation, were significantly higher (+42%) 3 h after the onset of dialysis treatment with flat-sheet than with hollow-fiber dialyzers. With respect to surface area, larger dialyzers tended to cause more release of leukocyte elastase as compared to dialyzers with smaller surface areas, irrespectively of the configuration of the dialyzer used. On the other hand, activation of the complement system, as measured by the generation of C3a-desarg, did not differ with both types of configurations. The same held true for leukopenia, which was almost identical for hollow-fiber and flat-sheet dialyzers. From these findings two lines of evidence emerge: First, not only the type of membrane material used in a dialyzer may influence its biocompatibility, but the geometry of the extracorporeal device also determines the degree of compatibility. Hence, the extent of leukocyte activation correlated with both configuration of the dialyzer and surface area of the membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Cholesterol Crystals Activate the Lectin Complement Pathway via Ficolin-2 and Mannose-Binding Lectin

    DEFF Research Database (Denmark)

    Pilely, Katrine; Rosbjerg, Anne; Genster, Ninette

    2016-01-01

    Cholesterol crystals (CC) play an essential role in the formation of atherosclerotic plaques. CC activate the classical and the alternative complement pathways, but the role of the lectin pathway is unknown. We hypothesized that the pattern recognition molecules (PRMs) from the lectin pathway bind...... CC and function as an upstream innate inflammatory signal in the pathophysiology of atherosclerosis. We investigated the binding of the PRMs mannose-binding lectin (MBL), ficolin-1, ficolin-2, and ficolin-3, the associated serine proteases, and complement activation products to CC in vitro using...... recognize CC and provides evidence for an important role for this pathway in the inflammatory response induced by CC in the pathophysiology of atherosclerosis....

  17. Potassium humate inhibits complement activation and the production of inflammatory cytokines in vitro

    Energy Technology Data Exchange (ETDEWEB)

    van Rensburg, C.E.J.; Naude, P.J. [University of Pretoria, Pretoria (South Africa)

    2009-08-15

    The effects of brown coal derived potassium humate on lymphocyte proliferation, cytokine production and complement activation were investigated in vitro. Potassium humate increased lymphocyte proliferation of phytohaemaglutinin A (PHA) and pokeweed mitogen (PWM) stimulated mononuclear lymphocytes (MNL) in vitro from concentrations of 20 to 80 {mu} g/ml, in a dose dependant manner. On the other hand potassium humate, at 40 {mu} g/ml, significantly inhibited the release of TNF-alpha, IL-1 beta, IL-6 and IL-10 by PHA stimulated MNL. Regarding complement activation it was found that potassium humate inhibits the activation of both the alternative and classical pathways without affecting the stability of the red blood cell membranes. These results indicate that the anti-inflammatory potential of potassium humate could be partially due to the inhibition of pro-inflammatory cytokines responsible for the initiation of these reactions as well as inhibition of complement activation. The increased lymphocyte proliferation observed, might be due to increased IL-2 production as previously been documented.

  18. Variants in Complement Factor H and Complement Factor H-Related Protein Genes, CFHR3 and CFHR1, Affect Complement Activation in IgA Nephropathy.

    Science.gov (United States)

    Zhu, Li; Zhai, Ya-Ling; Wang, Feng-Mei; Hou, Ping; Lv, Ji-Cheng; Xu, Da-Min; Shi, Su-Fang; Liu, Li-Jun; Yu, Feng; Zhao, Ming-Hui; Novak, Jan; Gharavi, Ali G; Zhang, Hong

    2015-05-01

    Complement activation is common in patients with IgA nephropathy (IgAN) and associated with disease severity. Our recent genome-wide association study of IgAN identified susceptibility loci on 1q32 containing the complement regulatory protein-encoding genes CFH and CFHR1-5, with rs6677604 in CFH as the top single-nucleotide polymorphism and CFHR3-1 deletion (CFHR3-1∆) as the top signal for copy number variation. In this study, to explore the clinical effects of variation in CFH, CFHR3, and CFHR1 on IgAN susceptibility and progression, we enrolled two populations. Group 1 included 1178 subjects with IgAN and available genome-wide association study data. Group 2 included 365 subjects with IgAN and available clinical follow-up data. In group 1, rs6677604 was associated with mesangial C3 deposition by genotype-phenotype correlation analysis. In group 2, we detected a linkage between the rs6677604-A allele and CFHR3-1∆ and found that the rs6677604-A allele was associated with higher serum levels of CFH and lower levels of the complement activation split product C3a. Furthermore, CFH levels were positively associated with circulating C3 levels and negatively associated with mesangial C3 deposition. Moreover, serum levels of the pathogenic galactose-deficient glycoform of IgA1 were also associated with the degree of mesangial C3 deposition in patients with IgAN. Our findings suggest that genetic variants in CFH, CFHR3, and CFHR1 affect complement activation and thereby, predispose patients to develop IgAN. Copyright © 2015 by the American Society of Nephrology.

  19. Hepatitis C virus NS3/4A protease inhibits complement activation by cleaving complement component 4.

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    Seiichi Mawatari

    Full Text Available BACKGROUND: It has been hypothesized that persistent hepatitis C virus (HCV infection is mediated in part by viral proteins that abrogate the host immune response, including the complement system, but the precise mechanisms are not well understood. We investigated whether HCV proteins are involved in the fragmentation of complement component 4 (C4, composed of subunits C4α, C4β, and C4γ, and the role of HCV proteins in complement activation. METHODS: Human C4 was incubated with HCV nonstructural (NS 3/4A protease, core, or NS5. Samples were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and then subjected to peptide sequencing. The activity of the classical complement pathway was examined using an erythrocyte hemolysis assay. The cleavage pattern of C4 in NS3/4A-expressing and HCV-infected cells, respectively, was also examined. RESULTS: HCV NS3/4A protease cleaved C4γ in a concentration-dependent manner, but viral core and NS5 did not. A specific inhibitor of NS3/4A protease reduced C4γ cleavage. NS3/4A protease-mediated cleavage of C4 inhibited classical pathway activation, which was abrogated by a NS3/4A protease inhibitor. In addition, co-transfection of cells with C4 and wild-type NS3/4A, but not a catalytic-site mutant of NS3/4A, produced cleaved C4γ fragments. Such C4 processing, with a concomitant reduction in levels of full-length C4γ, was also observed in HCV-infected cells expressing C4. CONCLUSIONS: C4 is a novel cellular substrate of the HCV NS3/4A protease. Understanding disturbances in the complement system mediated by NS3/4A protease may provide new insights into the mechanisms underlying persistent HCV infection.

  20. Genetically engineered fusion of MAP-1 and factor H domains 1-5 generates a potent dual upstream inhibitor of both the lectin and alternative complement pathways

    DEFF Research Database (Denmark)

    Nordmaj, Mie Anemone; Munthe-Fog, Lea; Hein, Estrid

    2015-01-01

    Inhibition of the complement cascade has emerged as an option for treatment of a range of diseases. Mannose-binding lectin/ficolin/collectin-associated protein (MAP-1) is a pattern recognition molecule (PRM)-associated inhibitor of the lectin pathway. The central regulator of the alternative......:4 in a solid-phase functional assay, only the first 5 N-terminal domains of complement FH fused to the C-terminal part of full-length MAP-1 chimeric construct were able to combine inhibition of lectin and AP activation with an half maximal inhibitory concentration of ∼ 100 and 20 nM, respectively. No effect...

  1. Activity and activation of the complement system in patients being operated on for cancer of the colon

    DEFF Research Database (Denmark)

    Baatrup, G; Qvist, N; Junker, A

    1994-01-01

    OBJECTIVE: To find out if there was any local activation of complement in the vicinity of a colonic cancer, and any fluctuation in the function of the complement system during operation. DESIGN: Prospective study. SETTING: One university and two district hospitals in Denmark. SUBJECTS: 29 selected...... patients undergoing emergency and elective operations for colonic cancer. INTERVENTIONS: Measurements of systemic and local complement fixation capacity and complement activation in samples of serum or plasma taken before, during, and after operation. MAIN OUTCOME MEASURES: Changes in complement fixation...... capacity and complement activation during operation. RESULTS: Haemodilution during operation caused a significant reduction in the complement fixation capacity of serum and in the activation of the complement system as measured by generation of C3c. We were unable to confirm the presence of complement...

  2. Status analysis: A complement or an alternative to the class analysis

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    Antonić Slobodan

    2009-01-01

    Full Text Available The author discusses the relation between stratification and belonging to the status groups based on citizenship, race, gender or lifestyle (underclass. The author claims that the status analysis is not an alternative, but a complement to the class analysis. The life prospects of individuals in today's society depend not only on their position in the market (or in the system of production, but on their membership of a particular status group as well. Hence the Weberian approach - with two-dimensional, class and status analysis - is certainly more successful in dealing with all the complexities of social reality than the Marxist one. Therefore, if we add the third dimension of the Weber's stratification scheme - power, we can see that the exact social position of the individual could be determined the best by identification of its: position in the market (and the financial equivalent of the outcomes from it; position in a status group; and position in organizational structures (belonging to an organization and position that it occupies. Landowner or wage earner, citizen or immigrant, union activists or non-member, each of these positions mean a position either higher or lower on the stratification ladder. How this three-dimensional approach could be united into a single analytical matrix, and how could successful operationalization of it through appropriate indicators be made, still remains a challenge for researchers and statisticians. .

  3. The paralogous salivary anti-complement proteins IRAC I and IRAC II encoded by Ixodes ricinus ticks have broad and complementary inhibitory activities against the complement of different host species.

    Science.gov (United States)

    Schroeder, Hélène; Daix, Virginie; Gillet, Laurent; Renauld, Jean-Christophe; Vanderplasschen, Alain

    2007-02-01

    Several observations suggest that inhibition of the host complement alternative pathway by Ixodes tick saliva is crucial to achieve blood feeding. We recently described two paralogous anti-complement proteins called Ixodes ricinus anti-complement (IRAC) proteins I and II co-expressed in I. ricinus salivary glands. Phylogenetic analyses suggested that these sequences were diversifying by a process of positive Darwinian selection, possibly leading to molecules with different biological properties. In the present study, we tested the hypothesis that each paralogue may have different inhibitory activities against the complement of different natural host species, thereby contributing to broaden the host range of I. ricinus ticks. IRAC I and IRAC II were tested against the complement of eight I. ricinus natural host species (six mammals and two birds). The results demonstrate that IRAC I and IRAC II have broad and complementary inhibition activities against the complement of different host species. This report is the first description of paralogous anti-complement molecules encoded by a pathogen with broad and complementary inhibitory activities against the complement of different host species.

  4. Tuning complement activation and pathway through controlled molecular architecture of dextran chains in nanoparticle corona.

    Science.gov (United States)

    Coty, Jean-Baptiste; Eleamen Oliveira, Elquio; Vauthier, Christine

    2017-11-05

    The understanding of complement activation by nanomaterials is a key to a rational design of safe and efficient nanomedicines. This work proposed a systematic study investigating how molecular design of nanoparticle coronas made of dextran impacts on mechanisms that trigger complement activation. The nanoparticles used for this work consisted of dextran-coated poly(isobutylcyanoacrylate) (PIBCA) nanoparticles have already been thoroughly characterized. Their different capacity to trigger complement activation established on the cleavage of the protein C3 was also already described making these nanoparticles good models to investigate the relation between the molecular feature of their corona and the mechanism by which they triggered complement activation. Results of this new study show that complement activation pathways can be selected by distinct architectures formed by dextran chains composing the nanoparticle corona. Assumptions that explain the relation between complement activation mechanisms triggered by the nanoparticles and the nanoparticle corona molecular feature were proposed. These results are of interest to better understand how the design of dextran-coated nanomaterials will impact interactions with the complement system. It can open perspectives with regard to the selection of a preferential complement activation pathway or prevent the nanoparticles to activate the complement system, based on a rational choice of the corona configuration. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Human Properdin Opsonizes Nanoparticles and Triggers a Potent Pro-inflammatory Response by Macrophages without Involving Complement Activation

    Science.gov (United States)

    Kouser, Lubna; Paudyal, Basudev; Kaur, Anuvinder; Stenbeck, Gudrun; Jones, Lucy A.; Abozaid, Suhair M.; Stover, Cordula M.; Flahaut, Emmanuel; Sim, Robert B.; Kishore, Uday

    2018-01-01

    Development of nanoparticles as tissue-specific drug delivery platforms can be considerably influenced by the complement system because of their inherent pro-inflammatory and tumorigenic consequences. The complement activation pathways, and its recognition subcomponents, can modulate clearance of the nanoparticles and subsequent inflammatory response and thus alter the intended translational applications. Here, we report, for the first time, that human properdin, an upregulator of the complement alternative pathway, can opsonize functionalized carbon nanotubes (CNTs) via its thrombospondin type I repeat (TSR) 4 and 5. Binding of properdin and TSR4+5 is likely to involve charge pattern/polarity recognition of the CNT surface since both carboxymethyl cellulose-coated carbon nanotubes (CMC-CNT) and oxidized (Ox-CNT) bound these proteins well. Properdin enhanced the uptake of CMC-CNTs by a macrophage cell line, THP-1, mounting a robust pro-inflammatory immune response, as revealed by qRT-PCR, multiplex cytokine array, and NF-κB nuclear translocation analyses. Properdin can be locally synthesized by immune cells in an inflammatory microenvironment, and thus, its interaction with nanoparticles is of considerable importance. In addition, recombinant TSR4+5 coated on the CMC-CNTs inhibited complement consumption by CMC-CNTs, suggesting that nanoparticle decoration with TSR4+5, can be potentially used as a complement inhibitor in a number of pathological contexts arising due to exaggerated complement activation. PMID:29483907

  6. Complement activation by cholesterol crystals triggers a subsequent cytokine response

    DEFF Research Database (Denmark)

    Niyonzima, Nathalie; Halvorsen, Bente; Sporsheim, Bjørnar

    2017-01-01

    beneficial effects on atherosclerosis and a large clinical trial with an IL-1β inhibitor is currently in progress (the CANTOS study). However, upstream inhibition of CC-induced inflammation by using a complement inhibitor may be more efficient in treating atherosclerosis since this will block initiation...

  7. Detection and characterisation of Complement protein activity in bovine milk by bactericidal sequestration assay.

    Science.gov (United States)

    Maye, Susan; Stanton, Catherine; Fitzgerald, Gerald F; Kelly, Philip M

    2015-08-01

    While the Complement protein system in human milk is well characterised, there is little information on its presence and activity in bovine milk. Complement forms part of the innate immune system, hence the importance of its contribution during milk ingestion to the overall defences of the neonate. A bactericidal sequestration assay, featuring a Complement sensitive strain, Escherichia coli 0111, originally used to characterise Complement activity in human milk was successfully applied to freshly drawn bovine milk samples, thus, providing an opportunity to compare Complement activities in both human and bovine milks. Although not identical in response, the levels of Complement activity in bovine milk were found to be closely comparable with that of human milk. Differential counts of Esch. coli 0111 after 2 h incubation were 6.20 and 6.06 log CFU/ml, for raw bovine and human milks, respectively - the lower value representing a stronger Complement response. Exposing bovine milk to a range of thermal treatments e.g. 42, 45, 65, 72, 85 or 95 °C for 10 min, progressively inhibited Complement activity by increasing temperature, thus confirming the heat labile nature of this immune protein system. Low level Complement activity was found, however, in 65 and 72 °C heat treated samples and in retailed pasteurised milk which highlights the outer limit to which high temperature, short time (HTST) industrial thermal processes should be applied if retention of activity is a priority. Concentration of Complement in the fat phase was evident following cream separation, and this was also reflected in the further loss of activity recorded in low fat variants of retailed pasteurised milk. Laboratory-based churning of the cream during simulated buttermaking generated an aqueous (buttermilk) phase with higher levels of Complement activity than the fat phase, thus pointing to a likely association with the milk fat globule membrane (MFGM) layer.

  8. Electroluminescent TCC, C3dg and fB/Bb epitope assays for profiling complement cascade activation in vitro using an activated complement serum calibration standard.

    Science.gov (United States)

    van Vuuren, B Jansen; Bergseth, G; Mollnes, T E; Shaw, A M

    2014-01-15

    Electroluminescent assays for epitopes on the complement components C3dg, terminal complement complex (TCC) and factor B/Bb (fB/Bb) have been developed with capture and detection antibodies to produce detection limits C3dg=91±9ng/mL, TCC=3±0.1ng/mL and fB=55.7±0.1ng/mL. The assay performance was assessed against a series of zymosan and heat aggregated IgG (HAIgG) in vitro activations of complement using a calibrated activated complement serum (ACS) as calibration standard. The ACS standard was stable within 20% accuracy over a 6-month period with freeze-thaw cycles as required. Differential activation of the complement cascade was observed for TCC showing a pseudo-first order formation half-life of 3.5h after activation with zymosan. The C3dg activation fragment indicates a 10% total activation for both activation agents. The kinetic-epitope analysis for fB indicates that the capture epitope is on the fB/Bb protein fragment which can then become covered by the formation of C3bBb or C3bBbP complexes during the time course of the cascade. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. The Scl1 protein of M6-type group A Streptococcus binds the human complement regulatory protein, factor H, and inhibits the alternative pathway of complement.

    Science.gov (United States)

    Caswell, Clayton C; Han, Runlin; Hovis, Kelley M; Ciborowski, Pawel; Keene, Douglas R; Marconi, Richard T; Lukomski, Slawomir

    2008-02-01

    Non-specific activation of the complement system is regulated by the plasma glycoprotein factor H (FH). Bacteria can avoid complement-mediated opsonization and phagocytosis through acquiring FH to the cell surface. Here, we characterize an interaction between the streptococcal collagen-like protein Scl1.6 of M6-type group A Streptococcus (GAS) and FH. Using affinity chromatography with immobilized recombinant Scl1.6 protein, we co-eluted human plasma proteins with molecular weight of 155 kDa, 43 kDa and 38 kDa. Mass spectrometry identified the 155 kDa band as FH and two other bands as isoforms of the FH-related protein-1. The identities of all three bands were confirmed by Western immunoblotting with specific antibodies. Structure-function relation studies determined that the globular domain of the Scl1.6 variant specifically binds FH while fused to collagenous tails of various lengths. This binding is not restricted to Scl1.6 as the phylogenetically linked Scl1.55 variant also binds FH. Functional analyses demonstrated the cofactor activity of the rScl1.6-bound FH for factor I-mediated cleavage of C3b. Finally, purified FH bound to the Scl1.6 protein present in the cell wall material obtained from M6-type GAS. In conclusion, we have identified a functional interaction between Scl1 and plasma FH, which may contribute to GAS evasion of complement-mediated opsonization and phagocytosis.

  10. Anti-complement activity in the saliva of phlebotomine sand flies and other haematophagous insects.

    Science.gov (United States)

    Cavalcante, R R; Pereira, M H; Gontijo, N F

    2003-07-01

    The saliva of haematophagous insects has a series of pharmacological activities which may favour blood feeding. In the present study, an inhibitory effect on the complement system was observed in salivary extracts obtained from the phlebotomine sand flies Lutzomyia longipalpis and Lu. migonei. Saliva from Lu. longipalpis was capable of inhibiting both the classical and alternative pathways, while that from Lu. migonei acted only on the former. Other haematophagous insect species were screened for inhibition of the classical pathway. The triatomine bugs Panstrongylus megistus, Triatoma brasiliensis and Rhodnius prolixus were also able to inhibit the classical pathway whereas the mosquito Aedes aegyti and flea Ctenocephalides felis were not. The activity of Lu. longipalpis saliva on the classical pathway was partially characterized. The inhibitor is a protein of Mr 10000-30000 Da, which is very resistant to denaturation by heat. The inhibition of the complement system by phlebotomine sand flies may have a role in the transmission of Leishmania to the vertebrate hosts. The inhibitor molecule is thus a promising component of a vaccine to target salivary immunomodulators.

  11. Complementing xeroderma pigmentosum fibroblasts restore biological activity to UV-damaged DNA

    International Nuclear Information System (INIS)

    Day, R.S. III; Kraemer, K.H.; Robbins, J.H.

    1975-01-01

    UV survival curves of adenovirus 2 using fused complementing xeroderma pigmentosum fibroblast strains as virus hosts showed a component with an inactivation slope identical to that given by normal cells. This component was not observed when the fibroblasts were not fused or when fusions involved strains in the same complementing group. Extrapolation to zero dose indicated that three percent of the viral plaque-forming units had infected cells capable of normal repair; this suggested that three percent of the cells were complementing heterokaryons. Thus, heterokaryons formed from xeroderma pigmentosum fibroblasts belonging to different complementation groups are as capable of restoring biological activity to UV-damaged adenovirus 2 as are normal cells

  12. The Emerging Role of Complement Lectin Pathway in Trypanosomatids: Molecular Bases in Activation, Genetic Deficiencies, Susceptibility to Infection, and Complement System-Based Therapeutics

    Directory of Open Access Journals (Sweden)

    Ingrid Evans-Osses

    2013-01-01

    Full Text Available The innate immune system is evolutionary and ancient and is the pivotal line of the host defense system to protect against invading pathogens and abnormal self-derived components. Cellular and molecular components are involved in recognition and effector mechanisms for a successful innate immune response. The complement lectin pathway (CLP was discovered in 1990. These new components at the complement world are very efficient. Mannan-binding lectin (MBL and ficolin not only recognize many molecular patterns of pathogens rapidly to activate complement but also display several strategies to evade innate immunity. Many studies have shown a relation between the deficit of complement factors and susceptibility to infection. The recently discovered CLP was shown to be important in host defense against protozoan microbes. Although the recognition of pathogen-associated molecular patterns by MBL and Ficolins reveal efficient complement activations, an increase in deficiency of complement factors and diversity of parasite strategies of immune evasion demonstrate the unsuccessful effort to control the infection. In the present paper, we will discuss basic aspects of complement activation, the structure of the lectin pathway components, genetic deficiency of complement factors, and new therapeutic opportunities to target the complement system to control infection.

  13. Rivaroxaban limits complement activation compared with warfarin in antiphospholipid syndrome patients with venous thromboembolism.

    Science.gov (United States)

    Arachchillage, D R J; Mackie, I J; Efthymiou, M; Chitolie, A; Hunt, B J; Isenberg, D A; Khamashta, M; Machin, S J; Cohen, H

    2016-11-01

    Essentials Complement activation has a pathogenic role in thrombotic antiphospholipid syndrome (APS). Coagulation proteases such as factor Xa can activate complement proteins. Complement activation markers were elevated in anticoagulated thrombotic APS patients. Complement activation decreased in APS patients switching from warfarin to rivaroxaban. Background Complement activation may play a major role in the pathogenesis of thrombotic antiphospholipid syndrome (APS). Coagulation proteases such as factor Xa can activate complement proteins. Aims To establish whether rivaroxaban, a direct factor Xa inhibitor, limits complement activation compared with warfarin in APS patients with previous venous thromboembolism (VTE). Methods A total of 111 APS patients with previous VTE, on warfarin target INR 2.5, had blood samples taken at baseline and at day 42 after randomization in the RAPS (Rivaroxaban in Antiphospholipid Syndrome) trial. Fifty-six patients remained on warfarin and 55 switched to rivaroxaban. Fifty-five normal controls (NC) were also studied. Markers of complement activation (C3a, C5a, terminal complement complex [SC5b-9] and Bb fragment) were assessed. Results APS patients had significantly higher complement activation markers compared with NC at both time-points irrespective of the anticoagulant. There were no differences between the two patient groups at baseline, or patients remaining on warfarin at day 42. In 55 patients randomized to rivaroxaban, C3a, C5a and SC5b-9 were lower at day 42 (median (ng mL -1 ) [confidence interval] 64 [29-125] vs. 83 [35-147], 9 [2-15] vs. 12 [4-18] and 171 [56-245] vs. 201 [66-350], respectively) but levels of Bb fragment were unchanged. There were no correlations between rivaroxaban levels and complement activation markers. Conclusions APS patients with previous VTE on warfarin exhibit increased complement activation, which is likely to occur via the classical pathway and is decreased by rivaroxaban administration

  14. Activation of the classical pathway of complement by tobacco glycoprotein (TGP).

    Science.gov (United States)

    Koethe, S M; Nelson, K E; Becker, C G

    1995-07-15

    Tobacco glycoprotein (TGP), a polyphenol-rich glycoprotein isolated from tobacco leaves, activates the classical complement pathway through a mechanism that appears to involve direct interaction with C1q. A binding site on C1q for TGP can be localized by competitive inhibition with DNA to a region located in the junction between the collagen-like and globular regions of the molecule. A protein with activity similar to TGP has also been isolated from cigarette smoke condensate (TGP-S); it shares a binding site on C1q with TGP and has similar functional activity, with the exception that complement activation does not proceed to formation of a C3 cleaving enzyme. The ability of TGP and TGP-S to activate complement can be partially duplicated using polyphenols associated with tobacco leaf and smoke, i.e., chlorogenic acid and rutin. These polyphenols also compete with TGP for a binding site on immobilized C1q, suggesting that the polyphenol portion of TGP is critical for activation of complement. These results provide an additional mechanism for complement activation by cigarette products that, in vivo, could result in a localized complement depletion, generation of biologically active complement cleavage products, and initiation of an inflammatory response.

  15. Soluble and immobilized graphene oxide activates complement system differently dependent on surface oxidation state

    DEFF Research Database (Denmark)

    Wibroe, Peter Popp; Petersen, Søren Vermehren; Bovet, Nicolas Emile

    2016-01-01

    on two related elements of innate immunity: the complement system and interleukin-6 (IL-6) release in human blood. In solution, there was a decrease in GO-mediated complement activation with decreasing surface oxygen content (and altered oxygen functionality), whereas with immobilized GO complement...... response were reversed and increased with decreasing oxygen content. GO solutions, at concentrations below complement activating threshold, did not induce IL-6 release from human blood leukocytes, and further dampened lipopolysaccharide-induced IL-6 release in the whole blood. The latter effect became more...... profound with GO's having higher oxygen content. This protective role of GO solutions, however, disappeared at higher concentrations above complement-activating threshold. We discuss these results in relation to GO surface structure and properties, and implications for local administration and development...

  16. Genetic analysis of complement C1s deficiency associated with systemic lupus erythematosus highlights alternative splicing of normal C1s gene

    DEFF Research Database (Denmark)

    Amano, Mariane T; Ferriani, Virgínia P L; Florido, Marlene P C

    2008-01-01

    Deficiencies of complement proteins of the classical pathway are strongly associated with the development of autoimmune diseases. Deficiency of C1r has been observed to occur concomitantly with deficiency in C1s and 9 out of 15 reported cases presented systemic lupus erythematosus (SLE). Here, we...... describe a family in which all four children are deficient in C1s but only two of them developed SLE. Hemolytic activity mediated by the alternative and the lectin pathways were normal, but classical pathway activation was absent in all children's sera. C1s was undetectable, while in the parents' sera...

  17. Spontaneous complement activation on human B cells results in localized membrane depolarization and the clustering of complement receptor type 2 and C3 fragments

    DEFF Research Database (Denmark)

    Løbner, Morten; Leslie, Robert G Q; Prodinger, Wolfgang M

    2009-01-01

    While our previous studies have demonstrated that complement activation induced by complement receptors type 2 (CR2/CD21) and 1 (CR1/CD35) results in C3-fragment deposition and membrane attack complex (MAC) formation in human B cells, the consequences of these events for B-cell functions remain u...

  18. The stability of complement-mediated bactericidal activity in human serum against Salmonella.

    Directory of Open Access Journals (Sweden)

    Colette M O'Shaughnessy

    Full Text Available The complement cascade includes heat-labile proteins and care is required when handling serum in order to preserve its functional integrity. We have previously used a whole human serum bactericidal assay to show that antibody and an intact complement system are required in blood for killing of invasive isolates of Salmonella. The aim of the present study was to evaluate the conditions under which human serum can be stored and manipulated while maintaining complement integrity. Serum bactericidal activity against Salmonella was maintained for a minimum of 35 days when stored at 4°C, eight days at 22°C and 54 hours at 37°C. Up to three freeze-thaw cycles had no effect on the persistence of bactericidal activity and hemolytic complement assays confirmed no effect on complement function. Delay in the separation of serum for up to four days from clotted blood stored at 22°C did not affect bactericidal activity. Dilution of serum resulted in an increased rate of loss of bactericidal activity and so serum should be stored undiluted. These findings indicate that the current guidelines concerning manipulation and storage of human serum to preserve complement integrity and function leave a large margin for safety with regards to bactericidal activity against Salmonella. The study provides a scheme for determining the requirements for serum handling in relation to functional activity of complement in other systems.

  19. Increased activity of the mannan-binding lectin complement activation pathway in patients with colorectal cancer

    DEFF Research Database (Denmark)

    Ytting, H; Jensenius, Jens Christian; Christensen, I J

    2004-01-01

    BACKGROUND: Postoperative bacterial infectious complications are frequent in patients with colorectal cancer (CRC), with subsequent increased recurrence rates and poor prognosis. Deficiency of the mannan-binding lectin (MBL) complement activation pathway may cause increased risk of infection......: Serum MBL concentrations and MBL/MASP activity were determined using immunofluorometric assays. The levels are presented as the median, inter-quartile range and range. RESULTS: Serum MBL levels were significantly (P cancer (1384 (400-2188) ng/mL) (median...... in the colon or rectum, and disease stages according to Dukes' classification. No statistical difference (P=0.20) in frequency of MBL deficiency was found between the patients (20%) and the donors (27%). CONCLUSIONS: Overall, the MBL complement activation pathway is significantly increased in patients...

  20. Spores of Mucor ramosissimus, Mucor plumbeus and Mucor circinelloides and their ability to activate human complement system in vitro.

    Science.gov (United States)

    Granja, Luiz Fernando Zmetek; Pinto, Lysianne; Almeida, Cátia Amancio; Alviano, Daniela Sales; Da Silva, Maria Helena; Ejzemberg, Regina; Alviano, Celuta Sales

    2010-03-01

    Complement activation by spores of Mucor ramosissimus, Mucor plumbeus and Mucor circinelloides was studied using absorbed human serum in the presence or absence of chelators (EGTA or EDTA). We found that the spore caused full complement activation when incubated with EGTA-Mg2+ or without chelators, indicating that the alternative pathway is mainly responsible for this response. In order to compare activation profiles from each species, ELISAs for C3 and C4 fragments, mannan binding lectin (MBL), C-reactive protein (CRP) and IgG studies were carried out. All proteins were present on the species tested. Immunofluorescence tests demonstrated the presence of C3 fragments on the surface of all samples, which were confluent throughout fungal surfaces. The same profile of C3, C4, MBL, CRP and IgG deposition, observed in all species, suggests a similar activation behavior for these species.

  1. Meeting Air Transportation Demand in 2025 by Using Larger Aircraft and Alternative Routing to Complement NextGen Operational Improvements

    Science.gov (United States)

    Smith, Jeremy C.; Guerreiro, Nelson M.; Viken, Jeffrey K.; Dollyhigh, Samuel M.; Fenbert, James W.

    2010-01-01

    A study was performed that investigates the use of larger aircraft and alternative routing to complement the capacity benefits expected from the Next Generation Air Transportation System (NextGen) in 2025. National Airspace System (NAS) delays for the 2025 demand projected by the Transportation Systems Analysis Models (TSAM) were assessed using NASA s Airspace Concept Evaluation System (ACES). The shift in demand from commercial airline to automobile and from one airline route to another was investigated by adding the route delays determined from the ACES simulation to the travel times used in the TSAM and re-generating new flight scenarios. The ACES simulation results from this study determined that NextGen Operational Improvements alone do not provide sufficient airport capacity to meet the projected demand for passenger air travel in 2025 without significant system delays. Using larger aircraft with more seats on high-demand routes and introducing new direct routes, where demand warrants, significantly reduces delays, complementing NextGen improvements. Another significant finding of this study is that the adaptive behavior of passengers to avoid congested airline-routes is an important factor when projecting demand for transportation systems. Passengers will choose an alternative mode of transportation or alternative airline routes to avoid congested routes, thereby reducing delays to acceptable levels for the 2025 scenario; the penalty being that alternative routes and the option to drive increases overall trip time by 0.4% and may be less convenient than the first-choice route.

  2. Structural insight into the recognition of complement C3 activation products by integrin receptors

    DEFF Research Database (Denmark)

    Bajic, Goran

    2015-01-01

    fragment C3a called anaphylatoxin. Complement leads to opsonization as the proteolytic fragment C3b becomes covalently linked to the activator surface through a reactive thioester. Self-surfaces are protected by complement regulators, whereas complement activation vividly amplifies on pathogens...... and their clearance by dendritic cells is mediated by αMβ2. The central molecule in my project, αMβ2 integrin, recognizes many diverse ligands including iC3b, but the molecular basis for such recognition was lacking. During my PhD I have obtained a major breakthrough in the dissection of iC3b interaction with αMβ2. I...

  3. Complement activation cascade triggered by PEG-PL engineered nanomedicines and carbon nanotubes: The challenges ahead

    DEFF Research Database (Denmark)

    Moghimi, S.M.; Andersen, Alina Joukainen; Hashemi, S.H.

    2010-01-01

    reactions to certain PEG-PL engineered nanomedicines in both experimental animals and man. These reactions are classified as pseudoallergy and may be associated with cardiopulmonary disturbance and other related symptoms of anaphylaxis. Recent studies suggest that complement activation may be a contributing......, but not a rate limiting factor, in eliciting hypersensitivity reactions to such nanomedicines in sensitive individuals. This is rather surprising since PEGylated structures are generally assumed to suppress protein adsorption and blood opsonization events including complement. Here, we examine the molecular...... basis of complement activation by PEG-PL engineered nanomedicines and carbon nanotubes and discuss the challenges ahead....

  4. Cyclodextrin Reduces Cholesterol Crystal-Induced Inflammation by Modulating Complement Activation

    DEFF Research Database (Denmark)

    Bakke, Siril S; Aune, Marie H; Niyonzima, Nathalie

    2017-01-01

    Cholesterol crystals (CC) are abundant in atherosclerotic plaques and promote inflammatory responses via the complement system and inflammasome activation. Cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (BCD) is a compound that solubilizes lipophilic substances. Recently we have shown...

  5. Citrem Modulates Internal Nanostructure of Glyceryl Monooleate Dispersions and Bypasses Complement Activation

    DEFF Research Database (Denmark)

    Wibroe, Peter P; Mat Azmi, Intan Diana Binti; Nilsson, Christa

    2015-01-01

    Lyotropic non-lamellar liquid crystalline (LLC) aqueous nanodispersions hold a great promise in drug solubilization and delivery, but these nanosystems often induce severe hemolysis and complement activation, which limit their applications for safe intravenous administration. Here, we engineer an...

  6. The Structure-Activity Relationship between Marine Algae Polysaccharides and Anti-Complement Activity

    Science.gov (United States)

    Jin, Weihua; Zhang, Wenjing; Liang, Hongze; Zhang, Quanbin

    2015-01-01

    In this study, 33 different polysaccharides were prepared to investigate the structure-activity relationships between the polysaccharides, mainly from marine algae, and anti-complement activity in the classical pathway. Factors considered included extraction methods, fractionations, molecular weight, molar ratio of galactose to fucose, sulfate, uronic acid (UA) content, linkage, branching, and the type of monosaccharide. It was shown that the larger the molecular weights, the better the activities. The molar ratio of galactose (Gal) to fucose (Fuc) was a positive factor at a concentration lower than 10 µg/mL, while it had no effect at a concentration more than 10 µg/mL. In addition, sulfate was necessary; however, the sulfate content, the sulfate pattern, linkage and branching had no effect at a concentration of more than 10 µg/mL. Moreover, the type of monosaccharide had no effect. Laminaran and UA fractions had no activity; however, they could reduce the activity by decreasing the effective concentration of the active composition when they were mixed with the active compositions. The effect of the extraction methods could not be determined. Finally, it was observed that sulfated galactofucan showed good anti-complement activity after separation. PMID:26712768

  7. A novel method for direct measurement of complement convertases activity in human serum.

    Science.gov (United States)

    Blom, A M; Volokhina, E B; Fransson, V; Strömberg, P; Berghard, L; Viktorelius, M; Mollnes, T E; López-Trascasa, M; van den Heuvel, L P; Goodship, T H; Marchbank, K J; Okroj, M

    2014-10-01

    Complement convertases are enzymatic complexes that play a central role in sustaining and amplification of the complement cascade. Impairment of complement function leads directly or indirectly to pathological conditions, including higher infection rate, kidney diseases, autoimmune- or neurodegenerative diseases and ischaemia-reperfusion injury. An assay for direct measurement of activity of the convertases in patient sera is not available. Existing assays testing convertase function are based on purified complement components and, thus, convertase formation occurs under non-physiological conditions. We designed a new assay, in which C5 blocking compounds enabled separation of the complement cascade into two phases: the first ending at the stage of C5 convertases and the second ending with membrane attack complex formation. The use of rabbit erythrocytes or antibody-sensitized sheep erythrocytes as the platforms for convertase formation enabled easy readout based on measurement of haemolysis. Thus, properties of patient sera could be studied directly regarding convertase activity and membrane attack complex formation. Another advantage of this assay was the possibility to screen for host factors such as C3 nephritic factor and other anti-complement autoantibodies, or gain-of-function mutations, which prolong the half-life of complement convertases. Herein, we present proof of concept, detailed description and validation of this novel assay. © 2014 British Society for Immunology.

  8. Ahmed et al., Afr J Tradit Complement Altern Med. (2011) 8(1):79-81 ...

    African Journals Online (AJOL)

    USER

    GLUCOSE TOLERANCE IN GLUCOSE-INDUCED HYPERGLYCEMIC MICE ... Faculty of Life Sciences, University of Development Alternative, House No. ... Malaysia, **New York City College of Technology, The City University of New York.

  9. Najafi Doulatabad et al., Afr J Tradit Complement Altern Med. (2013 ...

    African Journals Online (AJOL)

    AJTCAM

    significant improvement in physical pain management (P=0.007) and the ... incidence among women is double as compared to men (Phillip and Rumrill, 2009). ... Alternative treatments have included aerobic exercises, relaxation techniques,.

  10. Complement activating soluble pattern recognition molecules with collagen-like regions, mannan-binding lectin, ficolins and associated proteins

    DEFF Research Database (Denmark)

    Thiel, Steffen

    2007-01-01

    Mannan-binding lectin (MBL), L-ficolin, M-ficolin and H-ficolin are all complement activating soluble pattern recognition molecules with recognition domains linked to collagen-like regions. All four may form complexes with four structurally related proteins, the three MBL-associated serine...... proteases (MASPs), MASP-1, MASP-2 and MASP-3, and a smaller MBL-associated protein (MAp19). The four recognition molecules recognize patterns of carbohydrate or acetyl-group containing ligands. After binding to the relevant targets all four are able to activate the complement system. We thus have a system...... where four different and/or overlapping patterns of microbial origin or patterns of altered-self may be recognized, but in all cases the signalling molecules, the MASPs, are shared. MASP-1 and MASP-3 are formed from one gene, MASP1/3, by alternative splicing generating two different mRNAs from a single...

  11. Classical Complement Pathway Activation in the Kidneys of Women With Preeclampsia.

    Science.gov (United States)

    Penning, Marlies; Chua, Jamie S; van Kooten, Cees; Zandbergen, Malu; Buurma, Aletta; Schutte, Joke; Bruijn, Jan Anthonie; Khankin, Eliyahu V; Bloemenkamp, Kitty; Karumanchi, S Ananth; Baelde, Hans

    2015-07-01

    A growing body of evidence suggests that complement dysregulation plays a role in the pathogenesis of preeclampsia. The kidney is one of the major organs affected in preeclampsia. Because the kidney is highly susceptible to complement activation, we hypothesized that preeclampsia is associated with renal complement activation. We performed a nationwide search for renal autopsy material in the Netherlands using a computerized database (PALGA). Renal tissue was obtained from 11 women with preeclampsia, 25 pregnant controls, and 14 nonpregnant controls with hypertension. The samples were immunostained for C4d, C1q, mannose-binding lectin, properdin, C3d, C5b-9, IgA, IgG, and IgM. Preeclampsia was significantly associated with renal C4d-a stable marker of complement activation-and the classical pathway marker C1q. In addition, the prevalence of IgM was significantly higher in the kidneys of the preeclamptic women. No other complement markers studied differed between the groups. Our findings in human samples were validated using a soluble fms-like tyrosine kinase 1 mouse model of preeclampsia. The kidneys in the soluble fms-like tyrosine kinase 1-injected mice had significantly more C4 deposits than the control mice. The association between preeclampsia and renal C4d, C1q, and IgM levels suggests that the classical complement pathway is involved in the renal injury in preeclampsia. Moreover, our finding that soluble fms-like tyrosine kinase 1-injected mice develop excess C4 deposits indicates that angiogenic dysregulation may play a role in complement activation within the kidney. We suggest that inhibiting complement activation may be beneficial for preventing the renal manifestations of preeclampsia. © 2015 American Heart Association, Inc.

  12. Complement factor H protects mice from ischemic acute kidney injury but is not critical for controlling complement activation by glomerular IgM.

    Science.gov (United States)

    Goetz, Lindsey; Laskowski, Jennifer; Renner, Brandon; Pickering, Matthew C; Kulik, Liudmila; Klawitter, Jelena; Stites, Erik; Christians, Uwe; van der Vlag, Johan; Ravichandran, Kameswaran; Holers, V Michael; Thurman, Joshua M

    2018-05-01

    Natural IgM binds to glomerular epitopes in several progressive kidney diseases. Previous work has shown that IgM also binds within the glomerulus after ischemia/reperfusion (I/R) but does not fully activate the complement system. Factor H is a circulating complement regulatory protein, and congenital or acquired deficiency of factor H is a strong risk factor for several types of kidney disease. We hypothesized that factor H controls complement activation by IgM in the kidney after I/R, and that heterozygous factor H deficiency would permit IgM-mediated complement activation and injury at this location. We found that mice with targeted heterozygous deletion of the gene for factor H developed more severe kidney injury after I/R than wild-type controls, as expected, but that complement activation within the glomeruli remained well controlled. Furthermore, mice that are unable to generate soluble IgM were not protected from renal I/R, even in the setting of heterozygous factor H deficiency. These results demonstrate that factor H is important for limiting injury in the kidney after I/R, but it is not critical for controlling complement activation by immunoglobulin within the glomerulus in this setting. IgM binds to glomerular epitopes after I/R, but it is not a significant source of injury. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Complement activation, endothelial dysfunction, insulin resistance and chronic heart failure

    DEFF Research Database (Denmark)

    Bjerre, M.; Kistorp, C.; Hansen, T.K.

    2010-01-01

    CRP), endothelial activation (soluble E-selectin, sEsel)), endothelial damage/dysfunction (von Willebrand factor, vWf) and insulin resistance (IR) and prognosis in CHF remains unknown. Design. We investigated the association(s) between plasma sMAC, hsCRP, sEsel, vWf and IR (assessed by homeostatic model assessment...

  14. Complement activated granulocytes can cause autologous tissue destruction in man

    Directory of Open Access Journals (Sweden)

    E. Löhde

    1992-01-01

    Full Text Available Activation of polymorphonuclear granulocytes (PMNs by C5a is thought to be important in the pathogenesis of multiple organ failure during sepsis and after trauma. In our experiment exposure of human PMNs to autologous zymosan activated plasma (ZAP leads to a rapid increase in chemiluminescence. Heating the ZAP at 56°C for 30 min did not alter the changes, while untreated plasma induced only baseline activity. The respiratory burst could be completely abolished by decomplementation and preincubation with rabbit antihuman C5a antibodies. Observation of human omentum using electron microscopy showed intravascular aggregation of PMNs, with capillary thrombosis and diapedesis of the cells through endothelial junctions 90 s after exposure to ZAP. PMNs caused disruption of connections between the mesothelial cells. After 4 min the mesothelium was completely destroyed, and connective tissue and fat cells exposed. Native plasma and minimum essential medium did not induce any morphological changes. These data support the concept that C5a activated PMNs can cause endothelial and mesothelial damage in man. Even though a causal relationship between anaphylatoxins and organ failure cannot be proved by these experiments C5a seems to be an important mediator in the pathogenesis of changes induced by severe sepsis and trauma in man.

  15. Kucukoner et al., Afr J Tradit Complement Altern Med. (2013) 10(1 ...

    African Journals Online (AJOL)

    AJTCAM

    dx.doi.org/10.4314/ajtcam.v10i1.4. 21. COMPLEMENTARY AND ALTERNATIVE MEDICINE USAGE IN CANCER PATIENTS IN. SOUTHEAST OF TURKEY. Mehmet Kucukoner1, Zulfikar Bilge2, Abdurrahman Isıkdogan1, M. Ali Kaplan1, Ali Inal1 ...

  16. Morel et al., Afr J Tradit Complement Altern Med., (2017) 14(S): 28 ...

    African Journals Online (AJOL)

    Danielle

    EFFECTS OF WHOLE BODY VIBRATION INTERVENTION ON HANDGRIP STRENGTH OF ... Background: Whole body vibration (WBV) exercises have been investigated as an alternative and complementary ... It has beem reported that WBV exercises can lead to strength and power enhancements in a short period of.

  17. Sumer et al., Afr J Tradit Complement Altern Med. (2013) 10(4):137 ...

    African Journals Online (AJOL)

    AJTCAM

    effectiveness of treatments of complementary and alternative medicine (CAM) and practices ... Cultures of yeast and bacterial strains were grown for 10 hours in brain heart broth (Difco) at .... The culture plate was incubated at 37 ◦ C in a CO2.

  18. Da et al., Afr J Tradit Complement Altern Med., (2018) 15 (1): 174 ...

    African Journals Online (AJOL)

    FILKPIERE

    2017-12-29

    Dec 29, 2017 ... Faso, the leaves of Cassia alata are used in the treatment of several ..... The first phase is caused by an increase in vascular permeability resulting ... TNF α (tumor necrosis factor) (Clarke et al., 1996). .... antigenotoxic effects of Cassia alata L. Evidence-Based Complementary and Alternative Medicine, 1-11.

  19. An assay for the mannan-binding lectin pathway of complement activation

    DEFF Research Database (Denmark)

    Petersen, Steen Vang; Thiel, S; Jensen, L

    2001-01-01

    activation. Therefore, in a generally applicable complement activation assay specific for the MBL pathway, the activity of the classical pathway must be inhibited. This can be accomplished by exploiting the finding that high ionic strength buffers inhibit the binding of C1q to immune complexes and disrupt...

  20. Genetic, molecular and functional analyses of complement factor I deficiency

    DEFF Research Database (Denmark)

    Nilsson, S.C.; Trouw, L.A.; Renault, N.

    2009-01-01

    Complete deficiency of complement inhibitor factor I (FI) results in secondary complement deficiency due to uncontrolled spontaneous alternative pathway activation leading to susceptibility to infections. Current genetic examination of two patients with near complete FI deficiency and three patie...

  1. Depressed activation of the lectin pathway of complement in hereditary angioedema

    DEFF Research Database (Denmark)

    Varga, L; Széplaki, G; Laki, J

    2008-01-01

    ) in three complement activation pathways. Functional activity of the CP, LP and AP were measured in the sera of 68 adult patients with hereditary angioedema (HAE) and 64 healthy controls. In addition, the level of C1q, MBL, MBL-associated serine protease-2 (MASP-2), C4-, C3- and C1INH was measured...... by standard laboratory methods. MBL-2 genotypes were determined by polymerase chain reaction. Besides the complement alterations (low CP and C1INH activity, low C4-, C1INH concentrations), which characterize HAE, the level of MASP-2 was also lower (P = 0.0001) in patients compared with controls. Depressed LP...

  2. Tchikaya et al., Afr J Tradit Complement Altern Med. (2011) 8(4):452 ...

    African Journals Online (AJOL)

    AJTCAM

    Tissue preparation and recording of cardiac muscle contractile activity .... Mechanical activity of an isolated heart results in contractions of either average or ..... DHPR alpha1S subunit controls skeletal muscle mass and morphogenesis.

  3. Gupta et al., Afr J Tradit Complement Altern Med. (2011) 8(4):391 ...

    African Journals Online (AJOL)

    AJTCAM

    antioxidant activity while acetone extract showed presence of relatively high total phenol and ... of A. pindrow have demonstrated anti-inflammatory, analgesic, ... The stable DPPH was used for determination of free radical scavenging activity .... including increased activity of erythrocyte superoxide dismutase, a decrease in.

  4. Colostral whey concentrate supplement increases complement activity in the sera of neonatal calves.

    Science.gov (United States)

    Rokka, S; Korhonen, B H; Nousiainen, J; Marnila, P

    2001-08-01

    We evaluated the effect of a commercial bovine colostral whey on the complement-mediated immune responses of calves. Two groups of neonatal calves were fed, in addition to whole milk (WM) and pooled colostrum (PC), different amounts of a commercial immunoglobulin concentrate made from pooled colostral whey (Ig-C) for the first two feedings post natum. The control group was fed WM and PC only. Serum samples were obtained at the ages of 2, 7, 14 and 30 d. Bacteriolytic activity against complement-sensitive Escherichia coli JM103 and opsonic activity against complement-lysis-resistant E. coli IH3080 strains were studied, as well as the levels of C3 complement component and E. coli JM103 specific antibodies in the sera. Groups fed Ig-C had 2-3 times higher bacteriolytic activity than the control group of both the classic (P complement activities of serum can be increased substantially by feeding colostral whey concentrate to calves during their first days of life.

  5. Acute and prolonged complement activation in the central nervous system during herpes simplex encephalitis.

    Science.gov (United States)

    Eriksson, Charlotta E; Studahl, Marie; Bergström, Tomas

    2016-06-15

    Herpes simplex encephalitis (HSE) is characterized by a pronounced inflammatory activity in the central nervous system (CNS). Here, we investigated the acute and prolonged complement system activity in HSE patients, by using enzyme-linked immunosorbent assays (ELISAs) for numerous complement components (C). We found increased cerebrospinal fluid concentrations of C3a, C3b, C5 and C5a in HSE patients compared with healthy controls. C3a and C5a concentrations remained increased also compared with patient controls. Our results conclude that the complement system is activated in CNS during HSE in the acute phase, and interestingly also in later stages supporting previous reports of prolonged inflammation. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Classroom Active Learning Complemented by an Online Discussion Forum to Teach Sustainability

    Science.gov (United States)

    Dengler, Mary

    2008-01-01

    This paper identifies some of the pedagogical benefits of an active learning course delivery complemented by an online discussion forum to teach sustainability by evaluating the case of a geography master's course. The potential benefits and some challenges of an active learning course delivery to teach sustainability in geography and related…

  7. Arun et al., Afr J Tradit Complement Altern Med. (2015) 12(3):135 ...

    African Journals Online (AJOL)

    Proff.Adewunmi

    Materials and Methods: Preliminary wound healing activity of successive extracts of ... Wound healing; Hydroxyproline content; Antioxidant; Antimicrobial activity. ... Micrococcus luteus and Escherichia coli) and fungal culture (Candida ..... and also used as a marker of collagen synthesis (Lin et al., 2003; Rasik et al., 1992).

  8. Ibrahim et al., Afr J Tradit Complement Altern Med. (2013) 10(5):283 ...

    African Journals Online (AJOL)

    AJTCAM

    The anti-oxidative activities of sequentially extracted solvent fractions of different parts of P. biglobosa were evaluated in a series of in vitro assays. Our findings indicated that all extracts had electron donating and free radical scavenging activities. But the ethanol (EtOH) extracts from all the parts demonstrated more ...

  9. Zhang et al., Afr J Tradit Complement Altern Med. (2013) 10(5):401 ...

    African Journals Online (AJOL)

    cadewumi

    Stigma maydis polysaccharides can improve the symptoms of weight loss ... convergence activity, zeaxanthin that have vitamin A activity and other nutrient .... 2 d later, blood was sampled from caudal vein to determine the blood ... In comparison, mice in the normal control group had bright fur and hair, good spirit, normal.

  10. Methanol extract of grain dust shows complement fixing activity and other characteristics similar to tannic acid.

    Science.gov (United States)

    Skea, D; Broder, I

    1986-01-01

    We have found several similarities between tannic acid and grain dust extract prepared with methanol. Both formed a precipitate with IgG, and these interactions were inhibited by albumin. In addition, both preparations fixed complement; this activity was heat stable and was removed by prior adsorption of the preparations with hide powder. Adsorption with polyvinyl polypyrrolidone reduced the complement-fixing activity of tannic acid but not that of the methanol grain dust extract. The similarities between tannic acid and the methanol grain dust extract are consistent with the presence of a tannin or tanninlike material in grain dust. Images FIGURE 1. PMID:3709479

  11. The Sand Fly Salivary Protein Lufaxin Inhibits the Early Steps of the Alternative Pathway of Complement by Direct Binding to the Proconvertase C3b-B

    Science.gov (United States)

    Mendes-Sousa, Antonio F.; do Vale, Vladimir Fazito; Silva, Naylene C. S.; Guimaraes-Costa, Anderson B.; Pereira, Marcos H.; Sant’Anna, Mauricio R. V.; Oliveira, Fabiano; Kamhawi, Shaden; Ribeiro, José M. C.; Andersen, John F.; Valenzuela, Jesus G.; Araujo, Ricardo N.

    2017-01-01

    Saliva of the blood feeding sand fly Lutzomyia longipalpis was previously shown to inhibit the alternative pathway (AP) of the complement system. Here, we have identified Lufaxin, a protein component in saliva, as the inhibitor of the AP. Lufaxin inhibited the deposition of C3b, Bb, Properdin, C5b, and C9b on agarose-coated plates in a dose-dependent manner. It also inhibited the activation of factor B in normal serum, but had no effect on the components of the membrane attack complex. Surface plasmon resonance (SPR) experiments demonstrated that Lufaxin stabilizes the C3b-B proconvertase complex when passed over a C3b surface in combination with factor B. Lufaxin was also shown to inhibit the activation of factor B by factor D in a reconstituted C3b-B, but did not inhibit the activation of C3 by reconstituted C3b-Bb. Proconvertase stabilization does not require the presence of divalent cations, but addition of Ni2+ increases the stability of complexes formed on SPR surfaces. Stabilization of the C3b-B complex to prevent C3 convertase formation (C3b-Bb formation) is a novel mechanism that differs from previously described strategies used by other organisms to inhibit the AP of the host complement system. PMID:28912782

  12. The Sand Fly Salivary Protein Lufaxin Inhibits the Early Steps of the Alternative Pathway of Complement by Direct Binding to the Proconvertase C3b-B

    Directory of Open Access Journals (Sweden)

    Antonio F. Mendes-Sousa

    2017-08-01

    Full Text Available Saliva of the blood feeding sand fly Lutzomyia longipalpis was previously shown to inhibit the alternative pathway (AP of the complement system. Here, we have identified Lufaxin, a protein component in saliva, as the inhibitor of the AP. Lufaxin inhibited the deposition of C3b, Bb, Properdin, C5b, and C9b on agarose-coated plates in a dose-dependent manner. It also inhibited the activation of factor B in normal serum, but had no effect on the components of the membrane attack complex. Surface plasmon resonance (SPR experiments demonstrated that Lufaxin stabilizes the C3b-B proconvertase complex when passed over a C3b surface in combination with factor B. Lufaxin was also shown to inhibit the activation of factor B by factor D in a reconstituted C3b-B, but did not inhibit the activation of C3 by reconstituted C3b-Bb. Proconvertase stabilization does not require the presence of divalent cations, but addition of Ni2+ increases the stability of complexes formed on SPR surfaces. Stabilization of the C3b-B complex to prevent C3 convertase formation (C3b-Bb formation is a novel mechanism that differs from previously described strategies used by other organisms to inhibit the AP of the host complement system.

  13. The Sand Fly Salivary Protein Lufaxin Inhibits the Early Steps of the Alternative Pathway of Complement by Direct Binding to the Proconvertase C3b-B.

    Science.gov (United States)

    Mendes-Sousa, Antonio F; do Vale, Vladimir Fazito; Silva, Naylene C S; Guimaraes-Costa, Anderson B; Pereira, Marcos H; Sant'Anna, Mauricio R V; Oliveira, Fabiano; Kamhawi, Shaden; Ribeiro, José M C; Andersen, John F; Valenzuela, Jesus G; Araujo, Ricardo N

    2017-01-01

    Saliva of the blood feeding sand fly Lutzomyia longipalpis was previously shown to inhibit the alternative pathway (AP) of the complement system. Here, we have identified Lufaxin, a protein component in saliva, as the inhibitor of the AP. Lufaxin inhibited the deposition of C3b, Bb, Properdin, C5b, and C9b on agarose-coated plates in a dose-dependent manner. It also inhibited the activation of factor B in normal serum, but had no effect on the components of the membrane attack complex. Surface plasmon resonance (SPR) experiments demonstrated that Lufaxin stabilizes the C3b-B proconvertase complex when passed over a C3b surface in combination with factor B. Lufaxin was also shown to inhibit the activation of factor B by factor D in a reconstituted C3b-B, but did not inhibit the activation of C3 by reconstituted C3b-Bb. Proconvertase stabilization does not require the presence of divalent cations, but addition of Ni 2+ increases the stability of complexes formed on SPR surfaces. Stabilization of the C3b-B complex to prevent C3 convertase formation (C3b-Bb formation) is a novel mechanism that differs from previously described strategies used by other organisms to inhibit the AP of the host complement system.

  14. Cristina et al., Afr J Tradit Complement Altern Med. (2014) 11(3):1-6 1

    African Journals Online (AJOL)

    cadewumi

    100 ml E. cyparissias, 20% mother tincture previously obtained was .... conjunctive tissue, nuclei and fibres (Șincai, 2000), microscopy being .... Studies made by our research team about the active compounds of .... J Invert Pathol, 67: 15-20.

  15. Nadri et al., Afr J Tradit Complement Altern Med. (2015) 12(2):120 ...

    African Journals Online (AJOL)

    cadewumi

    to the presence of polar phenolic compounds as compared to other extraction .... activity since it forms a network of hydrogen bonds with other amino acids .... Histological changes in the heart and the proximal aorta in experimental diabetic.

  16. Bautista et al., Afr J Tradit Complement Altern Med. (2015) 12(4): 96 ...

    African Journals Online (AJOL)

    Proff.Adewunmi

    protective activities of Geranium genus used in traditional medicine. Results: Currently, eight ... properties and are of particular interest due to their proven beneficial therapeutic use in patients with allergies, asthma, diabetes, hypertension, and.

  17. Wei et al., Afr J Tradit Complement Altern Med. (2015) 12(5):127 ...

    African Journals Online (AJOL)

    Proff.Adewunmi

    AstragalosideIV was the active composition of Radix Astragali. ..... Radix Astragali has been used for the treatment of night sweats, deficiency of qi (e.g., fatigue, weakness, and loss of appetite) and diarrhea. ... Cancer Metastasis Rev.

  18. Jeruto et al., Afr J Tradit Complement Altern Med. (2016) 13(6):168 ...

    African Journals Online (AJOL)

    Conclusion: There is need to carry out research on root and stem barks to identify the active phytochemicals that ..... Glycyrrhiza glabra (liquorice) and Polygala senega (Seneca snakeroot) .... Indian J of Fund and Appl Life Sci, 1 (2): 1 - 10. 5.

  19. Shi et al., Afr J Tradit Complement Altern Med. (2015) 12(6):169-179 ...

    African Journals Online (AJOL)

    Proff.Adewunmi

    ... indicating that ethyl acetate extracts of TA leaves are efficacious in attenuating oxidative stress in the liver of ... Antioxidant and antibacterial activities of polyphenolic compounds from bitter cumin (Cuminum .... functions and human disease.

  20. Seo et al., Afr J Tradit Complement Altern Med. (2013) 10 (1):113-123

    African Journals Online (AJOL)

    AJTCAM

    huo-tang, Jiin-koka-to, Simultaneous determination. Introduction. Many herbal formulae have been used to prevent and treat various diseases. Such herbal medicines have few side effects and exhibit multiple activities (Zhang et al., 2004; Jiang, ...

  1. Oyebanji et al., Afr J Tradit Complement Altern Med. (2014) 11(1):30 ...

    African Journals Online (AJOL)

    cadewumi

    Background: The anti-inflammatory and anti-nociceptive activity of betulinic acid ... Materials and Methods: Rats and mice were randomly divided into groups of five ..... attracted attention because of its pharmacological potentials with particular ...

  2. Asan Ozusaglam et al., Afr J Tradit Complement Altern Med. (2013 ...

    African Journals Online (AJOL)

    AJTCAM

    Key words: Allium scabriflorum, Allium tchihatschewii, antimicrobial activity, ..... They found that A. roseum essential oil had a high effect against gram ..... oregano (Origanum vulgare) shoot cultures inoculated with Pseudomonas species.

  3. Complement activation in the Parkinson's disease substantia nigra: an immunocytochemical study

    Directory of Open Access Journals (Sweden)

    Conant Stephanie B

    2006-10-01

    Full Text Available Abstract Background Inflammatory processes are increased in the Parkinson's disease (PD brain. The long-term use of nonsteroidal anti-inflammatory drugs has been associated, in retrospective studies, with decreased risk for PD, suggesting that inflammation may contribute to development of this disorder. The objective of this study was to determine the extent of complement activation, a major inflammatory mechanism, in PD. Methods Substantia nigra specimens from young normal subjects (n = 11–13, aged normal subjects (n = 24–28, and subjects with PD (n = 19–20, Alzheimer's disease (AD; n = 12–13, and dementia with Lewy bodies (DLB; n = 9 were stained for iC3b and C9, representing early- and late-stage complement activation, respectively. Numbers of iC3b+, C9+, and total melanized neurons in each section were counted in a blinded fashion. Nonparametric analyses were used to evaluate differences between groups and to evaluate correlations between complement staining, numbers of melanized neurons, and the duration of PD. Results Lewy bodies in both PD and DLB specimens stained for iC3b and C9. Staining was also prominent on melanized neurons. The percentage of iC3b+ neurons was significantly increased in PD vs. aged normal and AD specimens, and in young normal vs. aged normal specimens. C9 immunoreactivity was significantly increased in PD vs. AD specimens, but unlike iC3b, the increased C9 staining in PD and young normal specimens did not achieve statistical significance vs. aged normal specimens. iC3b and C9 staining in PD specimens was not correlated with the numbers of remaining melanized neurons, nor with the duration of PD. Conclusion Complement activation occurs on Lewy bodies and melanized neurons in the PD substantia nigra. Early complement activation (iC3b is increased on melanized neurons in PD vs. aged normal specimens, and late-stage complement activation (C9 also tends to increase. This latter finding suggests that complement

  4. The United States Chiropractic Workforce: An alternative or complement to primary care?

    Directory of Open Access Journals (Sweden)

    Davis Matthew A

    2012-11-01

    Full Text Available Abstract Background In the United States (US a shortage of primary care physicians has become evident. Other health care providers such as chiropractors might help address some of the nation’s primary care needs simply by being located in areas of lesser primary care resources. Therefore, the purpose of this study was to examine the distribution of the chiropractic workforce across the country and compare it to that of primary care physicians. Methods We used nationally representative data to estimate the per 100,000 capita supply of chiropractors and primary care physicians according to the 306 predefined Hospital Referral Regions. Multiple variable Poisson regression was used to examine the influence of population characteristics on the supply of both practitioner-types. Results According to these data, there are 74,623 US chiropractors and the per capita supply of chiropractors varies more than 10-fold across the nation. Chiropractors practice in areas with greater supply of primary care physicians (Pearson’s correlation 0.17, p-value  Conclusion These findings suggest that chiropractors practice in areas of greater primary care physician supply. Therefore chiropractors may be functioning in more complementary roles to primary care as opposed to an alternative point of access.

  5. A teleost CD46 is involved in the regulation of complement activation and pathogen infection.

    Science.gov (United States)

    Li, Mo-Fei; Sui, Zhi-Hai; Sun, Li

    2017-11-03

    In mammals, CD46 is involved in the inactivation of complement by factor I (FI). In teleost, study on the function of CD46 is very limited. In this study, we examined the immunological property of a CD46 molecule (CsCD46) from tongue sole, a teleost species with important economic value. We found that recombinant CsCD46 (rCsCD46) interacted with FI and inhibited complement activation in an FI-dependent manner. rCsCD46 also interacted with bacterial pathogens via a different mechanism to that responsible for the FI interaction, involving different rCsCD46 sites. Cellular study showed that CsCD46 was expressed on peripheral blood leukocytes (PBL) and protected the cells against the killing effect of complement. When the CsCD46 on PBL was blocked by antibody before incubation of the cells with bacterial pathogens, cellular infection was significantly reduced. Consistently, when tongue sole were infected with bacterial pathogens in the presence of rCsCD46, tissue dissemination and survival of the pathogens were significantly inhibited. These results provide the first evidence to indicate that CD46 in teleosts negatively regulates complement activation via FI and protects host cells from complement-induced damage, and that CD46 is required for optimal bacterial infection probably by serving as a receptor for the bacteria.

  6. Novel assays to assess the functional capacity of the classical, the alternative and the lectin pathways of the complement system

    DEFF Research Database (Denmark)

    Palarasah, Y; Nielsen, C; Sprogøe, U

    2011-01-01

    is therefore of great importance. In this study, we present novel improved enzyme-linked immunosorbent assays for the functional assessment of the three individual pathways of the complement system. The method is applicable at high serum concentrations and we demonstrate that it minimizes both false negative...... as well as false positive results. In particular, for the functional mannose-binding lectin activity it represents an improvement on the existing assays. In this respect, the present assays represent novel improved diagnostic protocols for patients with suspected immunodeficiencies related...

  7. Chen et al., Afr J Tradit Complement Altern Med. (2016) 13(1):25-32 ...

    African Journals Online (AJOL)

    PROF ADEWUNMI

    The phosphorylation of PKA substrate was not activated after 48 hours of treatment with ephedrine and anisodamine. Conclusion: Ephedrine and anisodamine inhibit the proliferation of SKBR3 cells via a significantly change of intracellular cAMP concentration. Key words: anisodamine, breast cancer, cyclic adenosine ...

  8. Wang et al., Afr J Tradit Complement Altern Med. (2016) 13(1):134 ...

    African Journals Online (AJOL)

    PROF ADEWUNMI

    ACTIVATION OF DIFFERENT CEREBRAL FUNCTIONAL REGIONS FOLLOWING ACUPUNCTURE AT BOT .... Therefore, on basis of previous studies, in order to explore the brain function ... The location of KI3 and LR3 were identified in .... and face, and perception of space relation; 3) emotion functions, including emotion.

  9. Okeleye et al., Afr J Tradit Complement Altern Med. (2015) 12(1):1-8 ...

    African Journals Online (AJOL)

    cadewumi

    Key words: Peltophorum africanum, antioxidant, phytochemicals, polyphenolics, radicals. Introduction .... Total flavonoid was determined using the method of Ordonez et al. (2006). ... In vitro antioxidant capacities ... Scavenging activity of hydrogen peroxide by the plant extract was estimated using the method of Nabavi et al.

  10. Sireeratawong et al., Afr J Tradit Complement Altern Med. (2012) 9(4 ...

    African Journals Online (AJOL)

    AJTCAM

    However, the scientific data to support the reputed anti-diarrheal activity and toxicity of the .... and the Organization of Economic Co-operation and Development (OECD) ..... Gastrointestinal (GI) transit may be coordinated by relaxation of the circular ... nerves reduce blood flow to the gut, and decrease secretions, motility and ...

  11. Adeoye-Isijola et al., Afr J Tradit Complement Altern Med., (2018) 15 ...

    African Journals Online (AJOL)

    Morenike

    2018-02-23

    Feb 23, 2018 ... face of treatment failures and multidrug resistance plaguing the world. ... as a lead for investigating its biological activities and medicinal ... It grows wildly on decaying wood during the raining season from ..... reduce joint pain, swelling and morning stiffness associated with rheumatoid arthritis (Allayee et al., ...

  12. Wang et al., Afr J Tradit Complement Altern Med. (2015) 12(5):118 ...

    African Journals Online (AJOL)

    Proff.Adewunmi

    Using randomized controlled clinical research method, random number table was generated by statistics software. 30 healthy volunteers ..... Observation on activating effectiveness of acupuncture at acupoints and non-acupoints on different brain ... children with ADHD revealed by resting-state functional MRI. Brain Dev ...

  13. Qabaha Afr J Tradit Complement Altern Med. (2013) 10(4):101-108 ...

    African Journals Online (AJOL)

    AJTCAM

    resistant microorganisms, urging the search for new and effective drugs. Emerging and re-emerging pathogens are also other reasons to screen for suitable drugs (Darwish et al., 2010; Nascimento et al., 2000a; Nimri et al., 1999). Medicinal plants contain active compounds that are effective in treatment of chronic as well as ...

  14. Bli et al., Afr J Tradit Complement Altern Med. (2017) 14(2):47-59 doi ...

    African Journals Online (AJOL)

    Administrator

    Bovine respiratory diseases threaten the healthy development of the cattle breeding ... Administration signals basic acceptance of TCM in western countries (Xu, 2008). ... that Chinese medicinal herbs can fully activate the immune system to enhance immunity. ..... The immunology of the bovine respiratory disease complex.

  15. Halim et al, Afr J Tradit Complement Altern Med. (2018) 15 (2): 19 ...

    African Journals Online (AJOL)

    user

    2018-02-23

    Feb 23, 2018 ... He L, Fong J, von Zastrow M, Whistler JL. (2002). Regulation ... Keith DE, Murray SR, Zaki PA, Chu PC, Lissin DV, Kang L, Evans CJ, von Zastrow M. (1996). Morphine activates ... Tao PL, Lee HY, Chang LR, Loh HH. (1990).

  16. Chaiwongsa et al., Afr J Tradit Complement Altern Med. (2013) 10(1 ...

    African Journals Online (AJOL)

    AJTCAM

    induced by IL-1Я (P<0.05) concomitantly with a decrease in activities of these MMPs ... causes the progressive destruction of cartilage and bone (Feldmann et al., 1996). ... in vivo (Masuda and Jitoe, 1994) and protected cartilage degradation in the ... against a blue background corresponding to the hydrolysis of milk casein.

  17. Miao et al., Afr J Tradit Complement Altern Med. (2016) 13(2):52-60 ...

    African Journals Online (AJOL)

    acer

    metabolic control of exercise and activated the energy metabolism by increasing ... mice were housed in a room maintained at 23 ± 2°C with relative air humidity of 50 ± 5 % on a 12 h light-dark cycle. ... Compared with that of the C group, the.

  18. Okonkwo et al., Afr J Tradit Complement Altern Med. (2015) 12(2 ...

    African Journals Online (AJOL)

    cadewumi

    fasting blood sugar (FBS), packed cell volume (PCV), white blood cell (WBC), red blood ... medicine. More than 12 % of diabetes is associated with anaemia (Rani et al., 2010), ... crude methanol extracts of the stem, root, barks, leaves, fruits and seeds of A. ..... Animal models to test drugs with potential anti-diabetic activity.

  19. Zakaria et al., Afr J Tradit Complement Altern Med. (2016) 13(2):210 ...

    African Journals Online (AJOL)

    acer

    whole organism (i.e. an animal, bacterium or plant) as well as the effect on substructure of the organism (i.e. a cell, an organ such as ..... neuroprotective activities (Lacaille-Dubois and Wagner, 1996; Toker et al., 2004; Akachi et al., 2010; Agrawal, 2011; Czaplińska et al., ..... Acute oral toxicity of methanolic seed extract of.

  20. Xie et al., Afr J Tradit Complement Altern Med. (2013) 10(6):542-546 ...

    African Journals Online (AJOL)

    AJTCAM

    have been few. This paper mainly focused on the anti-cancer activity and cell cycle, and cell morphology analysis of L. C.H extracts. Materials and Methods ... Heng Qin equipment, Co., Ltd.), Clean Bench (100 Code Equipment Co., Ltd.), drain the incubator (Shanghai Yuejin Medical Apparatus Factory), and Micropipettes ...

  1. Wang et al., Afr J Tradit Complement Altern Med., (2017) 14 (5): 201 ...

    African Journals Online (AJOL)

    implad

    trace elements are maybe other functional compounds for medicinal effects. ... having a variety of biological activities, including anti-aging, immunoregulation, ... Unlike synthetic drugs, herbal medicine is a ... Material (100μg/mL) and were diluted to the corresponding metal solution. .... Isolation, structural characterization,.

  2. Ogunyinka et al., Afr J Tradit Complement Altern Med. (2015) 12(6 ...

    African Journals Online (AJOL)

    Proff.Adewunmi

    with 55% chlorogenic acid is available in the market. Barley malt extracts are also available in the market; their mechanisms of action are ..... Oboh, G., Akinyemi, A.J. and Ademiluyi, A.O. (2012). Inhibition of α-amylase and α-glucosidase activities by ethanolic extract of Telfairia occidentalis (fluted pumpkin) leaf. Asian. Pac.

  3. Mahomoodally Afr J Tradit Complement Altern Med. (2014) 11(6):1-32

    African Journals Online (AJOL)

    cadewumi

    Nonetheless, further research is needed to investigate the possible active constituents that ... phytochemicals resulting from their therapeutic ability towards diseases like cancer, ... of diseases for instance HIV /AIDS, malaria, diabetes, sickle-cell ..... leaves and Piper betle L. leaves. Drink once daily at night. Respiratory tract.

  4. Gulfishan and Akhtar Afr J Tradit Complement Altern Med. (2014) 11 ...

    African Journals Online (AJOL)

    cadewumi

    Antioxidants in a cosmetic emulsion formulation may be incorporated as active ingredients as they protect human skin from free ... Cherry is rich in water, sugars, vitamins A, B and C, pectin, phenolics and anthocyanins. It is a ... Distilled water was prepared in the Laboratory of Natural Products and Cosmetics, Department of.

  5. Liu et al., Afr J Tradit Complement Altern Med. (2013) 10(4):78-82 ...

    African Journals Online (AJOL)

    AJTCAM

    Tie Shu Ye is a plant in the genus Cycas in family Cycadaceae; its Latin name is Folium Cordylines Fruticosae, and it is the leaf of Cordyline fruticosa (L.) A. Cheval. .... The mechanism of morphine inhibiting gastric cancer progression in vitro might be associated with activation of caspase-9 and caspase-3 and inhibition of ...

  6. Vijayapandi et al., Afr J Tradit Complement Altern Med. (2013) 10(1 ...

    African Journals Online (AJOL)

    AJTCAM

    with ACAE and ACME at 0.25, 0.5, 0.75 and 1 mg/ml, but at higher dose of ACAE, ... antioxidant and anticholinesterase activity of Acorus calamus reported ..... Central nervous system studies on an ethanol extract of Acorus calamus rhizomes.

  7. Mahomoodally Afr J Tradit Complement Altern Med. (2014) 11(6):1-32

    African Journals Online (AJOL)

    cadewumi

    Essential oil of Daucus carota subsp. halophilus: Composition, antifungal activity and cytotoxicity. J. Ethnopharmacol., 119 (1): 129-134. 158. Tembhurne, S.V., and Sakarkar, D.M. (2012). Anti-obesity and hypoglycemic effect of ethanolic extract of Murraya koenigii (L) leaves in high fatty diet rats. Asian Pac J Trop Dis., 2 (1): ...

  8. Sireeratawong et al., Afr J Tradit Complement Altern Med. (2014) 11 ...

    African Journals Online (AJOL)

    cadewumi

    Background: In ayurvedic and Thai traditional medicine, the fruit of T. chebula is useful in arthritic disorders, inflammation, tumor, pains, chronic and recurrent fever. The study investigated the analgesic and anti-inflammatory activities in animal models. Materials and methods: The water extract of T. chebula fruit was ...

  9. Shahat et al., Afr J Tradit Complement Altern Med. (2017) 14(2):161 ...

    African Journals Online (AJOL)

    Sayed

    extracts, Serratia marcescens displayed inhibition zone ranged between 10-17 mm. The antimicrobial activity of plant extracts against bacteria was more effective than against fungi, which is similar to the results reported by Avato and Ertürk (Avato et al.,. 1997; Ertürk et al., 2003). Acknowledgments. The authors extend their ...

  10. Al-Numair et al., Afr J Tradit Complement Altern Med. (2014) 11(3 ...

    African Journals Online (AJOL)

    cadewumi

    Ceruloplasmin was determined using its copper oxidase activity by method .... A number of pathophysiological mechanisms have been proposed to explain ... changes in membrane permeability are the primary factors for cardio-toxicity .... Ceruloplasmin inhibits ferritin-dependent lipid peroxidation by catalyzing the oxidative.

  11. 175-169):1(13) 2016 (. Afr J Tradit Complement Altern Med and ...

    African Journals Online (AJOL)

    acer

    GP III: Rats were orally pretreated with Lyco (15 mg/kg b.w). GP IV: rats were pretreated ... via ATP depletion, which finally produce necrosis of hepatocytes. It provokes a state of .... Results obtained in table (4) showed that rats injected with Gala (GP III) caused a significant elevation in the phase I enzymes activities CYP1A1 ...

  12. Ghazala et al., Afr J Tradit Complement Altern Med. (2016) 13(3):54 ...

    African Journals Online (AJOL)

    Key words: Toxicity; Profenofos; esterase activity; issues; fish ... environmental matrices; e.g., water, air, soil and organisms (Fang et al., 2014; Salem et al., ... restricted and was banned in many countries such as European Union countries, Asia, etc. ..... behavioral pattern of fingerling common carp (Cyprinus carpio L., 1758).

  13. Zhou et al., Afr J Tradit Complement Altern Med. (2013) 10(4):175 ...

    African Journals Online (AJOL)

    AJTCAM

    A STUDY OF EXTRACTION PROCESS AND IN VITRO ANTIOXIDANT ACTIVITY OF. TOTAL PHENOLS FROM RHIZOMA IMPERATAE. Xian-rong Zhou* ..... Progress of Research on In Vitro Antioxidant Function Evaluation Methods,Meat Research, 11: 41-46. 4. Lai Wah Chan, Emily LC Cheah, Constance LL Saw, Wanyu ...

  14. Ngoupaye et al., Afr J Tradit Complement Altern Med. (2014) 11(1 ...

    African Journals Online (AJOL)

    cadewumi

    the western region of Cameroon), is a robust herb that grows virtually everywhere in .... Comparisons between experimental and control groups were performed by one-way ..... Moreover it has predictive validity for detecting SSRI effects. .... Is the forced swimming test a suitable model for revealing antidepressant activity?

  15. Gutierrez et al., Afr J Tradit Complement Altern Med. (2014) 11(2 ...

    African Journals Online (AJOL)

    cadewumi

    Since pre-Hispanic times it has been used as medicine, reports on ... acclimatized for a period of three days in their new environment before the ... Sections of 5:00µm, were processed for insulin-releasing activity using an irnmunocytochemistry kit. .... with glucose and glyceraldehyde, respectively, to experimental media.

  16. Al-Malkiet al., Afr J Tradit Complement Altern Med. (2016) 13(2):25 ...

    African Journals Online (AJOL)

    user

    Background: The aim of the present study was to evaluate in vivo anti-tumor activity of Balanites aegyptiaca fruits extracts in addition to its role in ... includes chemotherapy, immunotherapy, radiotherapy, and surgery in advanced grades and stages. However ..... kidney of mice and the possible protective role of tetrodotoxin.

  17. Zhang et al., Afr J Tradit Complement Altern Med. (2014) 11(1):62-66

    African Journals Online (AJOL)

    cadewumi

    Background: Vietnamese Sophora Root mainly contains active constituents such as alkaloids, and it has anti-tumour, antibacterial, and anti-inflammatory effects. The objective of the paper was to study the effects of Vietnamese Sophora Root on growth, adhesion, invasion and motility of mouse melanoma B16BL6 cells, and ...

  18. Zhang et al., Afr J Tradit Complement Altern Med., (2017) 14 (5): 41 ...

    African Journals Online (AJOL)

    Moreover, after mechanical injury the rupture of blood vessel activate the cytokines in the region of spinal cord. Inflammation is one of the major factors responsible for secondary injury to spinal cord. Evidences show the inflammatory mediators (TNFα and IL-6) and oxidative stress induces the process of apoptosis by ...

  19. El-Haskoury et al., Afr J Tradit Complement Altern Med. (2015) 12(4 ...

    African Journals Online (AJOL)

    Proff.Adewunmi

    Background: Honey has wide range of biological activities. It has effect on renal function, and urinary nitric oxide and prostaglandins level. The present study was conducted to evaluate diuretic potential of carob honey, collected from Morocco, in normal rats and the results were compared with use of furosemide. Materials ...

  20. Lu et al., Afr J Tradit Complement Altern Med. (2013) 10(5):313-317 ...

    African Journals Online (AJOL)

    cadewumi

    Gastric cancer is a common malignant disease of the human digestive system ... of new drugs that will be effective on the human body with very little side effects in the ... Cells on the 5th day from thawing were selected and used in the activity ...

  1. Li et al., Afr J Tradit Complement Altern Med. (2014) 11(5):54-60 http ...

    African Journals Online (AJOL)

    cadewumi

    ... antibody to antigen, destructing mast cell enzyme activation system as well as inhibiting release of histamine from mast cells (M. Bureau et al., 1993). ..... decrease and other mediators of inflammation decrease. All of the results we got in this ...

  2. Foudah et al., Afr J Tradit Complement Altern Med., (2017) 14 (5): 31 ...

    African Journals Online (AJOL)

    phenolic and flavonoid content of Astragalus squarrosus Bunge. Afr. J. Biotechnol., 10: 19176-19180. 2. Bagheri, S., L. Keyhani, M. Heydari and H. Dashti, 2015. Antinociceptive activity of Astragalus gummifer gum. (gum tragacanth) through the adrenergic system: An in vivo study in mice. J. Ayurveda Integr. Med., 6: 19-23.

  3. Sireeratawong et al., Afr J Tradit Complement Altern Med. (2013) 10 ...

    African Journals Online (AJOL)

    AJTCAM

    TOXICITY STUDIES OF THE WATER EXTRACT FROM THE CALYCES OF ... determined by oral feeding both male and female rats daily with the extract at ... a number of flavonoids gossypetin, hibiscetine and sabdaretine, ascorbic acid, ... an anti-atherosclerotic activity in cholesterol-fed rabbits and rats (Chen et al., 2003).

  4. Yuan et al., Afr J Tradit Complement Altern Med. (2014) 11(4):120 ...

    African Journals Online (AJOL)

    cadewumi

    Conclusions: Izalpinin exhibits inhibitory role of muscarinic receptor-related detrusor contractile activity, and it may be a promising lead ... For the therapy of overactive bladder syndrome, many drugs such as anti-muscarinic agents have exhibited significant clinical benefits ... Figure 1: Chemical structure of izalpinin.

  5. Adeneye et al., Afr J Tradit Complement Altern Med. (2014) 11(2 ...

    African Journals Online (AJOL)

    cadewumi

    42.4% of those with arthritis) had arthritis-attributable-to-activity-limitation (AAAL) and with an aging population this figure is expected to rise. (Woolf and Pfleger ... West Africa where decoctions made from its pulverized leaves are used for the local treatment of rheumatic pains, fever, wounds and diarrhea. (Ogungbamila and ...

  6. Polysaccharides from Sargassum thunbergii: Monthly variations and anti-complement and anti-tumour activities.

    Science.gov (United States)

    Jin, Weihua; Liu, Ge; Zhong, Weihong; Sun, Chaomin; Zhang, Quanbin

    2017-12-01

    Monthly variations of polysaccharides from Sargassum thunbergii and their anti-complement and anti-tumour activities were investigated. It was observed that an increase in fucose and total sugar contents occurred during the growth period (from early April to mid-June), accompanied by a decrease in molar ratios of other monosaccharides to fucose. The highest yields were obtained from early July to early September, which was in accordance with the significant increase in molar ratio of glucose to fucose and decrease in molar ratio of other monosaccharides to fucose. And the above results suggested that S. Thunbergii synthesized large amount of laminaran, the storage substance of brown algae, during the senescence period. However, sulfate contents were relatively stable in the life cycle of S. thunbergii. These results suggested that S. thunbergii synthesized complex sulfated heteropolysacchairdes during inactive period, while during other periods, it synthesized more sulfated galactofucan. All polysaccharides showed anti-complement activity, suggesting that the harvesting time did not influence the anti-complement activities. In the anti-tumour assay in vitro, the polysaccharides taken during the senescence period had much lower anti-tumour activity, suggesting that fucoidan, but not laminaran, determined the anti-tumour activities. Therefore, polysaccharides from S. thunbergii might have great potential in anti-complement and anti-tumour application. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. 377 Konan et al., Afr J Tradit Complement Altern Med. (2011) 8(4 ...

    African Journals Online (AJOL)

    AJTCAM

    aurantifolia (Rutaceae) sur le muscle lisse, Taenia coli de cobaye. Rev. Med. Pharm. Afr. 16: 103-112. 35. Souza, A., Aka, K.J., Abo, K.J.C., Datté, Y.J., Traoré, F. and M'Batchi, B. (2007). Myostimulating effect of the aqueous extract of Khaya senegalensis (Desr) A. Juss (Meliaceae) in isolated Taenia caeci contractile activity.

  8. Anuchapreeda et al., Afr J Tradit Complement Altern Med. (2017) 14 ...

    African Journals Online (AJOL)

    ASUS

    antiproliferative activities against human leukemia and stomach cancer cell lines (Tung et. al., 2013). The coumarins from the flowers of M. siamensis including ... seeded at a density of 1.0 × 104 cells/well in 96-well plate, and incubated overnight at 37 °C with 5% of CO2. Then, cells were treated with the four extracts (3-100 ...

  9. Lin-Na and Yong-Xiu Afr J Tradit Complement Altern Med. (2014) 11 ...

    African Journals Online (AJOL)

    cadewumi

    Evaluation of anti-athletic fatigue activity of Schizandra chinensis aqueous extracts in mice. Afr J Pharm Pharmacol 3: 593-597. 4. Cao, Y., Hu, Y., Liu, P., Zhao, H.X., Zhou, X.J., and Wei, Y.M. (2012). Effects of a Chinese traditional formula Kai Xin San (KXS) on chronic fatigue syndrome mice induced by forced wheel running ...

  10. Quezada-Lazaro et al., Afr J Tradit Complement Altern Med. (2016 ...

    African Journals Online (AJOL)

    Rodrígo Quezada-Lázaro,1 Eunice A. Fernández-Zuñiga,1 Abraham García,1. Elvira Garza-González,2 Laura Alvarez,3 María del ..... Camacho-Corona, M. R., Ramírez-Cabrera, M. A., González-Santiago, O., Garza-González, E.; de Paz Palacios, I., Luna-Herrera, J. (2008). Activity against drug resistant-tuberculosis strains ...

  11. Complement Activation Induces Neutrophil Adhesion and Neutrophil-Platelet Aggregate Formation on Vascular Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Magdalena Riedl

    2017-01-01

    Discussion: Therefore, our findings of (i neutrophils adhering to complement-activated endothelial cells, (ii the formation of neutrophil-platelet aggregates on endothelial cells, and (iii the ability of aHUS serum to induce similar effects identify a possible role for neutrophils in aHUS manifestation.

  12. Lectin Pathway of Complement Activation Is Associated with Vulnerability of Atherosclerotic Plaques

    DEFF Research Database (Denmark)

    Fumagalli, Stefano; Perego, Carlo; Zangari, Rosalia

    2017-01-01

    Inflammatory mechanisms may be involved in atherosclerotic plaque rupture. By using a novel histology-based method to quantify plaque instability here, we assess whether lectin pathway (LP) of complement activation, a major inflammation arm, could represent an index of plaque instability. Plaques...

  13. Human Secretory IgM Antibodies Activate Human Complement and Offer Protection at Mucosal Surface.

    Science.gov (United States)

    Michaelsen, T E; Emilsen, S; Sandin, R H; Granerud, B K; Bratlie, D; Ihle, O; Sandlie, I

    2017-01-01

    IgM molecules circulate in serum as large polymers, mainly pentamers, which can be transported by the poly-Ig receptor (pIgR) across epithelial cells to mucosal surfaces and released as secretory IgM (SIgM). The mucosal SIgM molecules have non-covalently attached secretory component (SC), which is the extracellular part of pIgR which is cleaved from the epithelial cell membrane. Serum IgM antibodies do not contain SC and have previously been shown to make a conformational change from 'a star' to a 'staple' conformation upon reaction with antigens on a cell surface, enabling them to activate complement. However, it is not clear whether SIgM similarly can induce complement activation. To clarify this issue, we constructed recombinant chimeric (mouse/human) IgM antibodies against hapten 5-iodo-4-hydroxy-3-nitro-phenacetyl (NIP) and in addition studied polyclonal IgM formed after immunization with a meningococcal group B vaccine. The monoclonal and polyclonal IgM molecules were purified by affinity chromatography on a column containing human SC in order to isolate joining-chain (J-chain) containing IgM, followed by addition of excess amounts of soluble SC to create SIgM (IgM J+ SC+). These SIgM preparations were tested for complement activation ability and shown to be nearly as active as the parental IgM J+ molecules. Thus, SIgM may offer protection against pathogens at mucosal surface by complement-mediated cell lysis or by phagocytosis mediated by complement receptors present on effector cells on mucosa. © 2016 The Foundation for the Scandinavian Journal of Immunology.

  14. Fcγ and Complement Receptors and Complement Proteins in Neutrophil Activation in Rheumatoid Arthritis: Contribution to Pathogenesis and Progression and Modulation by Natural Products

    Directory of Open Access Journals (Sweden)

    Adriana Balbina Paoliello-Paschoalato

    2015-01-01

    Full Text Available Rheumatoid arthritis (RA is a highly disabling disease that affects all structures of the joint and significantly impacts on morbidity and mortality in RA patients. RA is characterized by persistent inflammation of the synovial membrane lining the joint associated with infiltration of immune cells. Eighty to 90% of the leukocytes infiltrating the synovia are neutrophils. The specific role that neutrophils play in the onset of RA is not clear, but recent studies have evidenced that they have an important participation in joint damage and disease progression through the release of proteolytic enzymes, reactive oxygen species (ROS, cytokines, and neutrophil extracellular traps, in particular during frustrated phagocytosis of immune complexes (ICs. In addition, the local and systemic activation of the complement system contributes to the pathogenesis of RA and other IC-mediated diseases. This review discusses (i the participation of Fcγ and complement receptors in mediating the effector functions of neutrophils in RA; (ii the contribution of the complement system and ROS-dependent and ROS-independent mechanisms to joint damage in RA; and (iii the use of plant extracts, dietary compounds, and isolated natural compounds in the treatment of RA, focusing on modulation of the effector functions of neutrophils and the complement system activity and/or activation.

  15. Soluble IgM links apoptosis to complement activation in early alcoholic liver disease in mice.

    Science.gov (United States)

    Smathers, Rebecca L; Chiang, Dian J; McMullen, Megan R; Feldstein, Ariel E; Roychowdhury, Sanjoy; Nagy, Laura E

    2016-04-01

    Ethanol feeding in mice activates complement via C1q binding to apoptotic cells in the liver; complement contributes to ethanol-induced inflammation and injury. Despite the critical role of C1q in ethanol-induced injury, the mechanism by which ethanol activates C1q remains poorly understood. Secretory IgM (sIgM), traditionally considered to act as an anti-microbial, also has critical housekeeping functions, facilitating clearance of apoptotic cells, at least in part through activation of C1q. Therefore, we hypothesized that (1) ethanol-induced apoptosis in the liver recruits sIgM, facilitating the activation of C1q and complement and (2) C1INH (C1 esterase inhibitor), which inhibits C1 functional activity, prevents complement activation and decreases ethanol-induced liver injury. Female C57BL/6 wild-type, C1qa(-/-), BID(-/-) and sIgM(-/-) mice were fed ethanol containing liquid diets or pair-fed control diets. C1INH or vehicle was given via tail vein injection to ethanol- or pair-fed wild-type mice at 24 and 48h prior to euthanasia. Ethanol exposure increased apoptosis in the liver, as well as the accumulation of IgM in the liver. In the early stages of ethanol feeding, C1q co-localized with IgM in the peri-sinusoidal space of the liver and accumulation of IgM and C3b was dependent on ethanol-induced BID-dependent apoptosis. sIgM(-/-) mice were protected from both ethanol-induced activation of complement and early ethanol-induced liver injury when compared to wild-type mice. Treatment with C1INH also decreased hepatic C3b deposition and ethanol-induced injury. These data indicate that sIgM contributes to activation of complement and ethanol-induced increases in inflammatory cytokine expression and hepatocyte injury in the early stages of ethanol-induced liver injury. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Core shell methyl methacrylate chitosan nanoparticles: In vitro mucoadhesion and complement activation

    Directory of Open Access Journals (Sweden)

    F Atyabi

    2011-10-01

    Full Text Available Background and the purpose of the study: Studies show that chitosan nanoparticles increase mucoadhesivity and penetration of large molecules across mucosal surface. The aim of the present study was to investigate the use of thiolated chitosan in the development of polysaccharide-coated nanoparticles in order to confer specific functionality to the system. Methods: Methyl methacrylate nanoparticles were coated with thiolated chitosan using a radical polymerization method. Thiolation was carried out using glutathione (GSH to improve mucoadhesivity and permeation enhancing properties of chitosan. Mucoadhesion studies were carried out by calculating the amount of mucin adsorbed on nanoparticles in a specific period of time. Complement consumption was assessed in human serum (HS by measurement of the hemolytic capacity of the complement system after contact with nanoparticles.   Results:   The FT-IR and 1HNMR spectra both confirmed the synthesis and showed the conjugation of thiolated chitosan to methyl methacrylate (MMA homopolymer. Nanoparticles were spherical having a mean diameter within the range of about 334-650 nm and their positive zeta potential values indicated the presence of the cationic polysaccharide at the nanoparticle surface. Increasing the amount of thiolated chitosan led to mucoadhesivity and complement activation. However there was not dose dependent correlation between these phenomenons and the absence of thiolated chitosan led to particles with larger size, and without ability to activate complement process. Major conclusion: It can be concluded that nanoparticles could be used for the mucosal delivery of peptides and proteins. Results show that the thiolated chitosan had higher mucoadhesion and complement activation than unmodified chitosan.

  17. Intracellular Complement Activation Sustains T Cell Homeostasis and Mediates Effector Differentiation

    Science.gov (United States)

    Liszewski, M. Kathryn; Kolev, Martin; Le Friec, Gaelle; Leung, Marilyn; Bertram, Paula G.; Fara, Antonella F.; Subias, Marta; Pickering, Matthew C.; Drouet, Christian; Meri, Seppo; Arstila, T. Petteri; Pekkarinen, Pirkka T.; Ma, Margaret; Cope, Andrew; Reinheckel, Thomas; Rodriguez de Cordoba, Santiago; Afzali, Behdad; Atkinson, John P.; Kemper, Claudia

    2013-01-01

    Summary Complement is viewed as a critical serum-operative component of innate immunity, with processing of its key component, C3, into activation fragments C3a and C3b confined to the extracellular space. We report here that C3 activation also occurred intracellularly. We found that the T cell-expressed protease cathepsin L (CTSL) processed C3 into biologically active C3a and C3b. Resting T cells contained stores of endosomal and lysosomal C3 and CTSL and substantial amounts of CTSL-generated C3a. While “tonic” intracellular C3a generation was required for homeostatic T cell survival, shuttling of this intracellular C3-activation-system to the cell surface upon T cell stimulation induced autocrine proinflammatory cytokine production. Furthermore, T cells from patients with autoimmune arthritis demonstrated hyperactive intracellular complement activation and interferon-γ production and CTSL inhibition corrected this deregulated phenotype. Importantly, intracellular C3a was observed in all examined cell populations, suggesting that intracellular complement activation might be of broad physiological significance. PMID:24315997

  18. Human stem cell-derived retinal epithelial cells activate complement via collectin 11 in response to stress

    DEFF Research Database (Denmark)

    Fanelli, Giorgia; Gonzalez-Cordero, Anai; Gardner, Peter J

    2017-01-01

    induced-pluripotent stem cell (iPSC)-derived RPE cells, particularly with regard to the complement pathway. We focused on collectin-11 (CL-11), a pattern recognition molecule that can trigger complement activation in renal epithelial tissue. We found evidence of constitutive and hypoxia-induced expression......, failed to activate complement. The presence of CL-11 in healthy murine and human retinal tissues confirmed the biological relevance of CL-11. Our data describe a new trigger mechanism of complement activation that could be important in disease pathogenesis and therapeutic interventions....

  19. Bioactive lysophospholipids generated by hepatic lipase degradation of lipoproteins lead to complement activation via the classical pathway.

    Science.gov (United States)

    Ma, Wanchao; Paik, David C; Barile, Gaetano R

    2014-09-09

    We determined bioactivity of lysophospholipids generated by degradation of the low-density (LDL), very low-density (VLDL), and high-density (HDL) lipoproteins with hepatic lipase (HL), cholesterol esterase (CE), and lipoprotein-associated phospholipase A2 (Lp-PLA2). The LDL, VLDL, and HDL were treated with HL, CE, and Lp-PLA2 after immobilization on plates, and complement activation studies were performed with diluted human serum. Complement component 3 (C3) fixation, a marker for complement activation, was determined with a monoclonal anti-human C3d antibody. Enzymatic properties of HL and CE were assayed with triglyceride and phosphatidylcholine substrates for triglyceride hydrolase and phospholipase A activities. The ARPE-19 cells were used for viability studies. The HL degradation of human lipoproteins LDL, VLDL, or HDL results in the formation of modified lipoproteins that can activate the complement pathway. Complement activation is dose- and time-dependent upon HL and occurs via the classical pathway. Enzymatic studies suggest that the phospholipase A1 activity of HL generates complement-activating lysophospholipids. C-reactive protein (CRP), known to simultaneously interact with complement C1 and complement factor H (CFH), further enhances HL-induced complement activation. The lysophospholipids, 1-Palmitoyl-sn-glycero-3-phosphocholine and 1-Oleoyl-sn-glycero-3-phosphocholine, can be directly cytotoxic to ARPE-19 cells. The HL degradation of lipoproteins, known to accumulate in the outer retina and in drusen, can lead to the formation of bioactive lysophospholipids that can trigger complement activation and induce RPE cellular dysfunction. Given the known risk associations for age-related macular degeneration (AMD) with HL, CRP, and CFH, this study elucidates a possible damage pathway for age-related macular degeneration (AMD) in genetically predisposed individuals, that HL activity may lead to accumulation of lysophospholipids to initiate complement

  20. Arthrogenicity of type II collagen monoclonal antibodies associated with complement activation and antigen affinity.

    Science.gov (United States)

    Koobkokkruad, Thongchai; Kadotani, Tatsuya; Hutamekalin, Pilaiwanwadee; Mizutani, Nobuaki; Yoshino, Shin

    2011-11-04

    The collagen antibody-induced arthritis (CAIA) model, which employs a cocktail of monoclonal antibodies (mAbs) to type II collagen (CII), has been widely used for studying the pathogenesis of autoimmune arthritis. In this model, not all mAbs to CII are capable of inducing arthritis because one of the initial events is the formation of collagen-antibody immune complexes on the cartilage surface or in the synovium, and subsequent activation of the complement by the complexes induces arthritis, suggesting that a combination of mAbs showing strong ability to bind mouse CII and activate the complement may effectively induce arthritis in mice. In the present study, we examined the relationship between the induction of arthritis by the combination of IgG2a (CII-6 and C2A-12), IgG2b (CII-3, C2B-14 and C2B-16) and IgM (CM-5) subclones of monoclonal antibodies (mAb) of anti-bovine or chicken CII and the ability of mAbs to activate complement and bind mouse CII. DBA/1J mice were injected with several combinations of mAbs followed by lipopolysaccharide. Furthermore, the ability of mAbs to activate the complement and bind mouse CII was examined by ELISA. First, DBA/1J mice were injected with the combined 4 mAbs (CII-3, CII-6, C2B-14, and CM-5) followed by lipopolysaccharide, resulting in moderate arthritis. Excluding one of the mAbs, i.e., using only CII-3, CII-6, and C2B-14, induced greater inflammation of the joints. Next, adding C2A-12 but not C2B-16 to these 3 mAbs produced more severe arthritis. A combination of five clones, consisting of all 5 mAbs, was less effective. Histologically, mice given the newly developed 4-clone cocktail had marked proliferation of synovial tissues, massive infiltration by inflammatory cells, and severe destruction of cartilage and bone. Furthermore, 4 of the 6 clones (CII-3, CII-6, C2B-14, and C2A-12) showed not only a strong cross-reaction with mouse CII but also marked activation of the complement in vitro. The combination of 4 mAbs showing

  1. Arthrogenicity of type II collagen monoclonal antibodies associated with complement activation and antigen affinity

    Directory of Open Access Journals (Sweden)

    Mizutani Nobuaki

    2011-11-01

    Full Text Available Abstract Background The collagen antibody-induced arthritis (CAIA model, which employs a cocktail of monoclonal antibodies (mAbs to type II collagen (CII, has been widely used for studying the pathogenesis of autoimmune arthritis. In this model, not all mAbs to CII are capable of inducing arthritis because one of the initial events is the formation of collagen-antibody immune complexes on the cartilage surface or in the synovium, and subsequent activation of the complement by the complexes induces arthritis, suggesting that a combination of mAbs showing strong ability to bind mouse CII and activate the complement may effectively induce arthritis in mice. In the present study, we examined the relationship between the induction of arthritis by the combination of IgG2a (CII-6 and C2A-12, IgG2b (CII-3, C2B-14 and C2B-16 and IgM (CM-5 subclones of monoclonal antibodies (mAb of anti-bovine or chicken CII and the ability of mAbs to activate complement and bind mouse CII. Methods DBA/1J mice were injected with several combinations of mAbs followed by lipopolysaccharide. Furthermore, the ability of mAbs to activate the complement and bind mouse CII was examined by ELISA. Results First, DBA/1J mice were injected with the combined 4 mAbs (CII-3, CII-6, C2B-14, and CM-5 followed by lipopolysaccharide, resulting in moderate arthritis. Excluding one of the mAbs, i.e., using only CII-3, CII-6, and C2B-14, induced greater inflammation of the joints. Next, adding C2A-12 but not C2B-16 to these 3 mAbs produced more severe arthritis. A combination of five clones, consisting of all 5 mAbs, was less effective. Histologically, mice given the newly developed 4-clone cocktail had marked proliferation of synovial tissues, massive infiltration by inflammatory cells, and severe destruction of cartilage and bone. Furthermore, 4 of the 6 clones (CII-3, CII-6, C2B-14, and C2A-12 showed not only a strong cross-reaction with mouse CII but also marked activation of the

  2. P-I Snake Venom Metalloproteinase Is Able to Activate the Complement System by Direct Cleavage of Central Components of the Cascade

    Science.gov (United States)

    Pidde-Queiroz, Giselle; Magnoli, Fábio Carlos; Portaro, Fernanda C. V.; Serrano, Solange M. T.; Lopes, Aline Soriano; Paes Leme, Adriana Franco; van den Berg, Carmen W.; Tambourgi, Denise V.

    2013-01-01

    Background Snake Venom Metalloproteinases (SVMPs) are amongst the key enzymes that contribute to the high toxicity of snake venom. We have recently shown that snake venoms from the Bothrops genus activate the Complement system (C) by promoting direct cleavage of C-components and generating anaphylatoxins, thereby contributing to the pathology and spread of the venom. The aim of the present study was to isolate and characterize the C-activating protease from Bothrops pirajai venom. Results Using two gel-filtration chromatography steps, a metalloproteinase of 23 kDa that activates Complement was isolated from Bothrops pirajai venom. The mass spectrometric identification of this protein, named here as C-SVMP, revealed peptides that matched sequences from the P-I class of SVMPs. C-SVMP activated the alternative, classical and lectin C-pathways by cleaving the α-chain of C3, C4 and C5, thereby generating anaphylatoxins C3a, C4a and C5a. In vivo, C-SVMP induced consumption of murine complement components, most likely by activation of the pathways and/or by direct cleavage of C3, leading to a reduction of serum lytic activity. Conclusion We show here that a P-I metalloproteinase from Bothrops pirajai snake venom activated the Complement system by direct cleavage of the central C-components, i.e., C3, C4 and C5, thereby generating biologically active fragments, such as anaphylatoxins, and by cleaving the C1-Inhibitor, which may affect Complement activation control. These results suggest that direct complement activation by SVMPs may play a role in the progression of symptoms that follow envenomation. PMID:24205428

  3. Complement Evasion by Pathogenic Leptospira.

    Science.gov (United States)

    Fraga, Tatiana Rodrigues; Isaac, Lourdes; Barbosa, Angela Silva

    2016-01-01

    Leptospirosis is a neglected infectious disease caused by spirochetes from the genus Leptospira . Pathogenic microorganisms, notably those which reach the blood circulation such as Leptospira , have evolved multiple strategies to escape the host complement system, which is important for innate and acquired immunity. Leptospira avoid complement-mediated killing through: (i) recruitment of host complement regulators; (ii) acquisition of host proteases that cleave complement proteins on the bacterial surface; and, (iii) secretion of proteases that inactivate complement proteins in the Leptospira surroundings. The recruitment of host soluble complement regulatory proteins includes the acquisition of Factor H (FH) and FH-like-1 (alternative pathway), C4b-binding protein (C4BP) (classical and lectin pathways), and vitronectin (Vn) (terminal pathway). Once bound to the leptospiral surface, FH and C4BP retain cofactor activity of Factor I in the cleavage of C3b and C4b, respectively. Vn acquisition by leptospires may result in terminal pathway inhibition by blocking C9 polymerization. The second evasion mechanism lies in plasminogen (PLG) binding to the leptospiral surface. In the presence of host activators, PLG is converted to enzymatically active plasmin, which is able to degrade C3b, C4b, and C5 at the surface of the pathogen. A third strategy used by leptospires to escape from complement system is the active secretion of proteases. Pathogenic, but not saprophytic leptospires, are able to secrete metalloproteases that cleave C3 (central complement molecule), Factor B (alternative pathway), and C4 and C2 (classical and lectin pathways). The purpose of this review is to fully explore these complement evasion mechanisms, which act together to favor Leptospira survival and multiplication in the host.

  4. Increased complement C1q level marks active disease in human tuberculosis.

    Directory of Open Access Journals (Sweden)

    Yi Cai

    Full Text Available BACKGROUND: Complement functions as an important host defense system and complement C5 and C7 have been implicated in immunopathology of tuberculosis. However, little is known about the role of other complement components in tuberculosis. METHODS: Complement gene expression in peripheral blood mononuclear cells of tuberculosis patients and controls were determined using whole genome transcriptional microarray assays. The mRNA and protein levels of three C1q components, C1qA, C1qB, and C1qC, were further validated by qRT-PCR and enzyme-linked immunosorbent assay, respectively. The percentages of C1q expression in CD14 positive cells were determined by flow cytometry. Finally, C1qC protein level was quantified in the pleural fluid of tuberculosis and non-tuberculosis pleurisy. RESULTS: C1q expression increases significantly in the peripheral blood of patients with active tuberculosis compared to healthy controls and individuals with latent TB infection. The percentage of C1q-expressing CD14 positive cells is significantly increased in active TB patients. C1q expression in the peripheral blood correlates with sputum smear positivity in tuberculosis patients and is reduced after anti-tuberculosis chemotherapy. Notably, receiver operating characteristic analysis showed that C1qC mRNA levels in peripheral blood efficiently discriminate active from latent tuberculosis infection and healthy controls. Additionally, C1qC protein level in pleural effusion shows improved power in discriminating tuberculosis from non-tuberculosis pleurisy when compared to other inflammatory markers, such as IL-6 and TNF-α. CONCLUSIONS: C1q expression correlates with active disease in human tuberculosis. C1q could be a potential diagnostic marker to discriminate active tuberculosis from latent tuberculosis infection as well as tuberculosis pleurisy from non-tuberculosis pleurisy.

  5. Interactions of PLGA nanoparticles with blood components: protein adsorption, coagulation, activation of the complement system and hemolysis studies.

    Science.gov (United States)

    Fornaguera, Cristina; Calderó, Gabriela; Mitjans, Montserrat; Vinardell, Maria Pilar; Solans, Conxita; Vauthier, Christine

    2015-04-14

    The intravenous administration of poly(lactic-co-glycolic) acid (PLGA) nanoparticles has been widely reported as a promising alternative for delivery of drugs to specific cells. However, studies on their interaction with diverse blood components using different techniques are still lacking. Therefore, in the present work, the interaction of PLGA nanoparticles with blood components was described using different complementary techniques. The influence of different encapsulated compounds/functionalizing agents on these interactions was also reported. It is worth noting that all these techniques can be simply performed, without the need for highly sophisticated apparatus or skills. Moreover, their transference to industries and application of quality control could be easily performed. Serum albumin was adsorbed onto all types of tested nanoparticles. The saturation concentration was dependent on the nanoparticle size. In contrast, fibrinogen aggregation was dependent on nanoparticle surface charge. The complement activation was also influenced by the nanoparticle functionalization; the presence of a functionalizing agent increased complement activation, while the addition of an encapsulated compound only caused a slight increase. None of the nanoparticles influenced the coagulation cascade at low concentrations. However, at high concentrations, cationized nanoparticles did activate the coagulation cascade. Interactions of nanoparticles with erythrocytes did not reveal any hemolysis. Interactions of PLGA nanoparticles with blood proteins depended both on the nanoparticle properties and the protein studied. Independent of their loading/surface functionalization, PLGA nanoparticles did not influence the coagulation cascade and did not induce hemolysis of erythrocytes; they could be defined as safe concerning induction of embolization and cell lysis.

  6. Collectin-11/MASP complex formation triggers activation of the lectin complement pathway--the fifth lectin pathway initiation complex

    DEFF Research Database (Denmark)

    Ma, Ying Jie; Skjoedt, Mikkel-Ole; Garred, Peter

    2013-01-01

    Collectins and ficolins are important in the clearance of endogenous and exogenous danger materials. A new human collectin-11 was recently identified in low concentration in serum in complex with mannose-binding lectin (MBL)/ficolin-associated serine proteases. Collectin-11 binds to carbohydrate...... complement complex on C. albicans. Moreover, spiking collectin-11-depleted serum, which did not mediate complement activation, with recombinant collectin-11 restored the complement activation capability. These results define collectin-11 as the fifth recognition molecule in the lectin complement pathway...

  7. A novel method for direct measurement of complement convertases activity in human serum

    NARCIS (Netherlands)

    Blom, A.M.; Volokhina, E.B.; Fransson, V.; Stromberg, P.; Berghard, L.; Viktorelius, M.; Mollnes, T.E.; Lopez-Trascasa, M.; Heuvel, B. van den; Goodship, T.H.; Marchbank, K.J.; Okroj, M.

    2014-01-01

    Complement convertases are enzymatic complexes that play a central role in sustaining and amplification of the complement cascade. Impairment of complement function leads directly or indirectly to pathological conditions, including higher infection rate, kidney diseases, autoimmune- or

  8. Decommissioning alternatives, process and work activities

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The following outlines the topics discussed under Decommissioning Alternatives, Process and Work Activities: (1) decommissioning alternatives, (2) work activities for prompt removal/dismantling, (3) work activities for entombment with delayed dismantling, and (4) work activities for mothballing with delayed dismantling

  9. Arthrogenicity of type II collagen monoclonal antibodies associated with complement activation and antigen affinity

    OpenAIRE

    Koobkokkruad, Thongchai; Kadotani, Tatsuya; Hutamekalin, Pilaiwanwadee; Mizutani, Nobuaki; Yoshino, Shin

    2011-01-01

    Abstract Background The collagen antibody-induced arthritis (CAIA) model, which employs a cocktail of monoclonal antibodies (mAbs) to type II collagen (CII), has been widely used for studying the pathogenesis of autoimmune arthritis. In this model, not all mAbs to CII are capable of inducing arthritis because one of the initial events is the formation of collagen-antibody immune complexes on the cartilage surface or in the synovium, and subsequent activation of the complement by the complexes...

  10. Relationship between complement activation, cellular uptake and surface physicochemical aspects of novel PEG-modifed nanocapsules.

    OpenAIRE

    Mosqueira, Vanessa Carla Furtado; Legrand, Philippe; Gulik, Annette; Bourdon, Olivier; Gref, Ruxandra; Labarre, Denis; Barratt, Gillian

    2001-01-01

    ABSTRACT: The aim of our work was to examine the relationship between modi"cations of the surface of nanocapsules (NC) by adsorption or covalent grafting of poly(ethylene oxide) (PEG), and changes in their phospholipid (PL) content on complement activation (C3 cleavage) and on uptake by macrophages. The physicochemical characterization of the NC included an investigation of their properties, such as surface charge, size, hydrophilicity, morphology and homogeneity. This is the "rst ti...

  11. Complement activation and liver impairment in trichloroethylene-sensitized BALB/c mice.

    Science.gov (United States)

    Zhang, Jiaxiang; Zha, Wansheng; Wang, Feng; Jiang, Tao; Xu, Shuhai; Yu, Junfeng; Zhou, Chengfan; Shen, Tong; Wu, Changhao; Zhu, Qixing

    2013-01-01

    Our recent studies have shown that trichloroethylene (TCE) was able to induce multisystem injuries in the form of occupational medicamentosa-like dermatitis, including skin, kidney, and liver damages. However, the role of complement activation in the immune-mediated liver injury is not known. This study examined the role of complement activation in the liver injury in a mouse model of TCE-induced sensitization. Treatment of female BALB/c mice with TCE under specific dosing protocols resulted in skin inflammation and sensitization. Skin edema and erythema occurred in TCE-sensitized groups. Trichloroethylene sensitization produced liver histopathological lesions, increased serum alanine aminotransferase, aspartate transaminase activities, and the relative liver weight. The concentrations of serum complement components C3a-desArg, C5a-desArg, and C5b-9 were significantly increased in 24-hour, 48-hour, and 72-hour sensitization-positive groups treated with TCE and peaked in the 72-hour sensitization-positive group. Depositions of C3a, C5a, and C5b-9 into the liver tissue were also revealed by immunohistochemistry. Immunofluorescence further verified high C5b-9 expression in 24-hour, 48-hour, and 72-hour sensitization-positive groups in response to TCE treatment. Reverse transcription-polymerase chain reaction detected C3 messenger RNA expression in the liver, and this was significantly increased in 24-hour and 48-hour sensitization-positive groups with a transient reduction at 72 hours. These results provide the first experimental evidence that complement activation may play a key role in the generation and progression of immune-mediated hepatic injury by exposure to TCE.

  12. Human factor H-related protein 2 (CFHR2 regulates complement activation.

    Directory of Open Access Journals (Sweden)

    Hannes U Eberhardt

    Full Text Available Mutations and deletions within the human CFHR gene cluster on chromosome 1 are associated with diseases, such as dense deposit disease, CFHR nephropathy or age-related macular degeneration. Resulting mutant CFHR proteins can affect complement regulation. Here we identify human CFHR2 as a novel alternative pathway complement regulator that inhibits the C3 alternative pathway convertase and terminal pathway assembly. CFHR2 is composed of four short consensus repeat domains (SCRs. Two CFHR2 molecules form a dimer through their N-terminal SCRs, and each of the two C-terminal ends can bind C3b. C3b bound CFHR2 still allows C3 convertase formation but the CFHR2 bound convertases do not cleave the substrate C3. Interestingly CFHR2 hardly competes off factor H from C3b. Thus CFHR2 likely acts in concert with factor H, as CFHR2 inhibits convertases while simultaneously allowing factor H assisted degradation by factor I.

  13. Complement activation in astrocytomas: deposition of C4d and patient outcome

    International Nuclear Information System (INIS)

    Mäkelä, Katri; Helén, Pauli; Haapasalo, Hannu; Paavonen, Timo

    2012-01-01

    C4d is a cleavage product of complement component C4 and is considered to serve as a marker for the site of complement activation. In this study C4d staining of grade I-IV astrocytic tumors was studied to explore if there is an association between complement activation and the grade of tumor, or patient survival. Tissue micro-array samples of 102 astrocytomas were stained immunohistochemically. The material consisted of 9 pilocytic astrocytomas and 93 grade II-IV astrocytomas, of which 67 were primary resections and 26 recurrent tumors. The intensity of C4d staining as well as extent of C4d and CD34 staining were evaluated. The intensity of C4d staining was scored semiquantitatively. The extent of the staining was counted morphometrically with a point counting grid yielding a percent of C4d and CD34 positive area of the sample. The intensity and extent of C4d staining increased in grade II-IV diffusely infiltrating astrocytoma tumors in line with the malignancy grade (p = 0.034 and p = 0.016, respectively, Kruskal-Wallis test). However, C4d positive tumor area percentages were higher in grade I pilocytic astrocytomas than in grade II-IV diffusely infiltrating astrocytomas (p = 0.041, Mann–Whitney test). There was a significant correlation between CD34 positive and C4d positive endothelial area fraction in diffusely infiltrating astrocytomas (p < 0.001, Pearson correlation). In these tumors, the increasing intensity of C4d staining was also associated with worsened patient outcome (p = 0.014, log-rank test). The worsening of patient outcome and malignant progression of tumor cells seem to be connected to microenvironmental changes evoked by chronically activated complement

  14. Molluskan Hemocyanins Activate the Classical Pathway of the Human Complement System through Natural Antibodies.

    Science.gov (United States)

    Pizarro-Bauerle, Javier; Maldonado, Ismael; Sosoniuk-Roche, Eduardo; Vallejos, Gerardo; López, Mercedes N; Salazar-Onfray, Flavio; Aguilar-Guzmán, Lorena; Valck, Carolina; Ferreira, Arturo; Becker, María Inés

    2017-01-01

    Molluskan hemocyanins are enormous oxygen-carrier glycoproteins that show remarkable immunostimulatory properties when inoculated in mammals, such as the generation of high levels of antibodies, a strong cellular reaction, and generation of non-specific antitumor immune responses in some types of cancer, particularly for superficial bladder cancer. These proteins have the ability to bias the immune response toward a T h 1 phenotype. However, despite all their current uses with beneficial clinical outcomes, a clear mechanism explaining these properties is not available. Taking into account reports of natural antibodies against the hemocyanin of the gastropod Megathura crenulata [keyhole limpet hemocyanin (KLH)] in humans as well as other vertebrate species, we report here for the first time, the presence, in sera from unimmunized healthy donors, of antibodies recognizing, in addition to KLH, two other hemocyanins from gastropods with documented immunomodulatory capacities: Fisurella latimarginata hemocyanin (FLH) and Concholepas concholepas hemocyanin (CCH). Through an ELISA screening, we found IgM and IgG antibodies reactive with these hemocyanins. When the capacity of these antibodies to bind deglycosylated hemocyanins was studied, no decreased interaction was detected. Moreover, in the case of FLH, deglycosylation increased antibody binding. We evaluated through an in vitro complement deposition assay whether these antibodies activated the classical pathway of the human complement system. The results showed that all three hemocyanins and their deglycosylated counterparts elicited this activation, mediated by C1 binding to immunoglobulins. Thus, this work contributes to the understanding on how the complement system could participate in the immunostimulatory properties of hemocyanins, through natural, complement-activating antibodies reacting with these proteins. Although a role for carbohydrates cannot be completely ruled out, in our experimental setting

  15. Optimizing complement-activating antibody-based cancer immunotherapy: a feasible strategy?

    Directory of Open Access Journals (Sweden)

    Maio Michele

    2004-06-01

    Full Text Available Abstract Passive immunotherapy with monoclonal antibodies (mAb targeted to specific tumor-associated antigens is amongst the most rapidly expanding approaches to biological therapy of cancer. However, until now a limited number of therapeutic mAb has demonstrated clinical efficacy in selected neoplasia. Results emerging from basic research point to a deeper characterization of specific biological features of neoplastic cells as crucial to optimize the clinical potential of therapeutic mAb, and to identify cancer patients who represent the best candidates to antibody-based immunotherapy. Focus on the tissue distribution and on the functional role of membrane complement-regulatory proteins such as Protectin (CD59, which under physiologic conditions protects tissues from Complement (C-damage, might help to optimize the efficacy of immunotherapeutic strategies based on C-activating mAb.

  16. Complement Activation in Arterial and Venous Thrombosis is Mediated by Plasmin

    Directory of Open Access Journals (Sweden)

    Jonathan H. Foley

    2016-03-01

    Full Text Available Thrombus formation leading to vaso-occlusive events is a major cause of death, and involves complex interactions between coagulation, fibrinolytic and innate immune systems. Leukocyte recruitment is a key step, mediated partly by chemotactic complement activation factors C3a and C5a. However, mechanisms mediating C3a/C5a generation during thrombosis have not been studied. In a murine venous thrombosis model, levels of thrombin–antithrombin complexes poorly correlated with C3a and C5a, excluding a central role for thrombin in C3a/C5a production. However, clot weight strongly correlated with C5a, suggesting processes triggered during thrombosis promote C5a generation. Since thrombosis elicits fibrinolysis, we hypothesized that plasmin activates C5 during thrombosis. In vitro, the catalytic efficiency of plasmin-mediated C5a generation greatly exceeded that of thrombin or factor Xa, but was similar to the recognized complement C5 convertases. Plasmin-activated C5 yielded a functional membrane attack complex (MAC. In an arterial thrombosis model, plasminogen activator administration increased C5a levels. Overall, these findings suggest plasmin bridges thrombosis and the immune response by liberating C5a and inducing MAC assembly. These new insights may lead to the development of strategies to limit thrombus formation and/or enhance resolution.

  17. Mesenchymal Stem Cells Control Complement C5 Activation by Factor H in Lupus Nephritis

    Directory of Open Access Journals (Sweden)

    Haijun Ma

    2018-06-01

    Full Text Available Lupus nephritis (LN is one of the most severe complications of systemic lupus erythematosus (SLE caused by uncontrolled activation of the complement system. Mesenchymal stem cells (MSCs exhibit clinical efficacy for severe LN in our previous studies, but the underlying mechanisms of MSCs regulating complement activation remain largely unknown. Here we show that significantly elevated C5a and C5b-9 were found in patients with LN, which were notably correlated with proteinuria and different renal pathological indexes of LN. MSCs suppressed systemic and intrarenal activation of C5, increased the plasma levels of factor H (FH, and ameliorated renal disease in lupus mice. Importantly, MSCs transplantation up-regulated the decreased FH in patients with LN. Mechanistically, interferon-α enhanced the secretion of FH by MSCs. These data demonstrate that MSCs inhibit the activation of pathogenic C5 via up-regulation of FH, which improves our understanding of the immunomodulatory mechanisms of MSCs in the treatment of lupus nephritis. Keywords: Lupus nephritis, C5, MSCs, FH

  18. Zonulin as prehaptoglobin2 regulates lung permeability and activates the complement system.

    Science.gov (United States)

    Rittirsch, Daniel; Flierl, Michael A; Nadeau, Brian A; Day, Danielle E; Huber-Lang, Markus S; Grailer, Jamison J; Zetoune, Firas S; Andjelkovic, Anuska V; Fasano, Alessio; Ward, Peter A

    2013-06-15

    Zonulin is a protein involved in the regulation of tight junctions (TJ) in epithelial or endothelial cells. Zonulin is known to affect TJ in gut epithelial cells, but little is known about its influences in other organs. Prehaptoglobin2 has been identified as zonulin and is related to serine proteases (MASPs, C1qrs) that activate the complement system. The current study focused on the role of zonulin in development of acute lung injury (ALI) in C57BL/6 male mice following intrapulmonary deposition of IgG immune complexes. A zonulin antagonist (AT-1001) and a related peptide with permeability agonist activities (AT-1002) were employed and given intratracheally or intravenously. Also, zonulin was blocked in lung with a neutralizing antibody. In a dose-dependent manner, AT-1001 or zonulin neutralizing antibody attenuated the intensity of ALI (as quantitated by albumin leak, neutrophil accumulation, and proinflammatory cytokines). A similar pattern was found using the bacterial lipopolysaccharide model of ALI. Using confocal microscopy on sections of injured lungs, staining patterns for TJ proteins were discontinuous, reduced, and fragmented. As expected, the leak of blood products into the alveolar space confirmed the passage of 3 and 20 kDa dextran, and albumin. In contrast to AT-1001, application of the zonulin agonist AT-1002 intensified ALI. Zonulin both in vitro and in vivo induced generation of complement C3a and C5a. Collectively, these data suggest that zonulin facilitates development of ALI both by enhancing albumin leak and complement activation as well as increased buildup of neutrophils and cytokines during development of ALI.

  19. Activation of the human complement system by cholesterol-rich and pegylated liposomes - Modulation of cholesterol-rich liposome-mediated complement activation by elevated serum LDL and HDL levels

    DEFF Research Database (Denmark)

    Moghimi, S.M.; Hamad, I.; Bunger, R.

    2006-01-01

    level of S-protein-bound form of the terminal complex (SC5b-9). However, liposome-induced rise of SC5b-9 was significantly suppressed when serum HDL cholesterol levels increased by 30%. Increase of serum LDL to levels similar to that observed in heterozygous familial hypercholesterolemia also suppressed......Intravenously infused liposomes may induce cardiopulmonary distress in some human subjects, which is a manifestation of "complement activation-related pseudoallergy." We have now examined liposome-mediated complement activation in human sera with elevated lipoprotein (LDL and HDL) levels, since...... abnormal or racial differences in serum lipid profiles seem to modulate the extent of complement activation and associated adverse responses. In accordance with our earlier observations, cholesterol-rich (45 mol% cholesterol) liposomes activated human complement, as reflected by a significant rise in serum...

  20. Zonulin as prehaptoglobin2 regulates lung permeability and activates the complement system

    OpenAIRE

    Rittirsch, Daniel; Flierl, Michael A.; Nadeau, Brian A.; Day, Danielle E.; Huber-Lang, Markus S.; Grailer, Jamison J.; Zetoune, Firas S.; Andjelkovic, Anuska V.; Fasano, Alessio; Ward, Peter A.

    2013-01-01

    Zonulin is a protein involved in the regulation of tight junctions (TJ) in epithelial or endothelial cells. Zonulin is known to affect TJ in gut epithelial cells, but little is known about its influences in other organs. Prehaptoglobin2 has been identified as zonulin and is related to serine proteases (MASPs, C1qrs) that activate the complement system. The current study focused on the role of zonulin in development of acute lung injury (ALI) in C57BL/6 male mice following intrapulmonary depos...

  1. Relationship between complement activation, cellular uptake and surface physicochemical aspects of novel PEG-modified nanocapsules.

    Science.gov (United States)

    Mosqueira, V C; Legrand, P; Gulik, A; Bourdon, O; Gref, R; Labarre, D; Barratt, G

    2001-11-01

    The aim of our work was to examine the relationship between modifications of the surface of nanocapsules (NC) by adsorption or covalent grafting of poly(ethylene oxide) (PEG), and changes in their phospholipid (PL) content on complement activation (C3 cleavage) and on uptake by macrophages. The physicochemical characterization of the NC included an investigation of their properties, such as surface charge, size, hydrophilicity, morphology and homogeneity. This is the first time that such properties have been correlated with biological interactions for NC, a novel carrier system with a structure more complex than nanospheres. C3 crossed immunoelectrophoresis revealed the reduced activation for NC with longer PEG chain and higher density, although all formulations induced C3 cleavage to a lesser or greater extent. NC bearing PEG covalently bound to the surface were weaker activators of complement than plain PLA [poly(D,L-lactide)] NC or nanospheres (NS). Furthermore, the fluorescent/confocal microscopy of J774A1 cells in contact with NC reveal a dramatically reduced interaction with PEG-bearing NC. However, the way in which PEG was attached (covalent or adsorbed) seemed to affect the mechanism of uptake. Taken together, these results suggest that the low level of protein binding to NC covered with a high density of 20kDa PEG chains is likely to be due to the steric barriers surrounding these particles, which prevents protein adsorption and reduces their interaction with macrophages.

  2. Tumour exosomes display different differential mechanical and complement activation properties dependent on malignant state: implications in endothelial leakiness

    DEFF Research Database (Denmark)

    Whitehead, Bradley Joseph; Wu, Linping; Hvam, Michael Lykke

    2015-01-01

    (QNM AFM) to determine size and nanomechanical properties. Effect of HCV-29, T24 and FL3 exosomes on human umbilical vein endothelial cell (HUVEC) monolayer integrity was determined by transendothelial electrical resistance (TEER) measurements and transport was determined by flow cytometry. Complement......). Malignant cell-derived exosomes activated complement through calcium-sensitive pathways in a concentration-dependent manner. Conclusions : Malignant (metastatic and non-metastatic) cell line exosomes display a markedly reduced stiffness and adhesion but an increased complement activation compared to non...

  3. Complement lysis activity in autologous plasma is associated with lower viral loads during the acute phase of HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Michael Huber

    2006-11-01

    Full Text Available BACKGROUND: To explore the possibility that antibody-mediated complement lysis contributes to viremia control in HIV-1 infection, we measured the activity of patient plasma in mediating complement lysis of autologous primary virus. METHODS AND FINDINGS: Sera from two groups of patients-25 with acute HIV-1 infection and 31 with chronic infection-were used in this study. We developed a novel real-time PCR-based assay strategy that allows reliable and sensitive quantification of virus lysis by complement. Plasma derived at the time of virus isolation induced complement lysis of the autologous virus isolate in the majority of patients. Overall lysis activity against the autologous virus and the heterologous primary virus strain JR-FL was higher at chronic disease stages than during the acute phase. Most strikingly, we found that plasma virus load levels during the acute but not the chronic infection phase correlated inversely with the autologous complement lysis activity. Antibody reactivity to the envelope (Env proteins gp120 and gp41 were positively correlated with the lysis activity against JR-FL, indicating that anti-Env responses mediated complement lysis. Neutralization and complement lysis activity against autologous viruses were not associated, suggesting that complement lysis is predominantly caused by non-neutralizing antibodies. CONCLUSIONS: Collectively our data provide evidence that antibody-mediated complement virion lysis develops rapidly and is effective early in the course of infection; thus it should be considered a parameter that, in concert with other immune functions, steers viremia control in vivo.

  4. Ficolin-3-mediated lectin complement pathway activation in patients with subarachnoid hemorrhage

    DEFF Research Database (Denmark)

    Zanier, Elisa R; Zangari, Rosalia; Munthe-Fog, Lea

    2014-01-01

    OBJECTIVES: To assess the involvement of ficolin-3, the main initiator of the lectin complement pathway (LCP), in subarachnoid hemorrhage (SAH) pathology and outcome. METHODS: In this preliminary exploratory study, plasma concentration of ficolin-3 and of ficolin-3-mediated functional LCP activity...... the World Federation of Neurosurgical Societies grading scale; vasospasm, defined as neuro-worsening with angiographic confirmation of vessel narrowing; cerebral ischemia, defined as hypodense lesion on CT scan performed before discharge; and 6-month outcome, assessed using the Glasgow Outcome Scale....... RESULTS: In patients, no changes were detected for ficolin-3 compared with controls. Notably, however, ficolin-3-mediated functional LCP activity was reduced. Low levels of plasma ficolin-3 and ficolin-3-mediated functional LCP activity were related to SAH severity, vasospasm, and cerebral ischemia...

  5. An Anti-C1s Monoclonal, TNT003, Inhibits Complement Activation Induced by Antibodies Against HLA.

    Science.gov (United States)

    Thomas, K A; Valenzuela, N M; Gjertson, D; Mulder, A; Fishbein, M C; Parry, G C; Panicker, S; Reed, E F

    2015-08-01

    Antibody-mediated rejection (AMR) of solid organ transplants (SOT) is characterized by damage triggered by donor-specific antibodies (DSA) binding donor Class I and II HLA (HLA-I and HLA-II) expressed on endothelial cells. While F(ab')2 portions of DSA cause cellular activation and proliferation, Fc regions activate the classical complement cascade, resulting in complement deposition and leukocyte recruitment, both hallmark features of AMR. We characterized the ability of an anti-C1s monoclonal antibody, TNT003, to inhibit HLA antibody (HLA-Ab)-induced complement activation. Complement deposition induced by HLA-Ab was evaluated using novel cell- and bead-based assays. Human aortic endothelial cells (HAEC) were cultured with HLA-Ab and human complement; production of activated complement proteins was measured by flow cytometry. Additionally, C3d deposition was measured on single antigen beads (SAB) mixed with HLA-Ab and human complement. TNT003 inhibited HLA-Ab mediated complement deposition on HAEC in a concentration-dependent manner; C3a, C4a and C5a anaphylatoxin production was also diminished by TNT003. Finally, TNT003 blocked C3d deposition induced by Class I (HLAI-Ab)- and Class II (HLAII-Ab)-specific antibodies on SAB. These data suggest TNT003 may be useful for modulating the effects of DSA, as TNT003 inhibits complement deposition and split product formation generated by HLA-I/II-Ab in vitro. © 2015 The Authors. American Journal of Transplantation Published by Wiley Periodicals, Inc.

  6. Early Components of the Complement Classical Activation Pathway in Human Systemic Autoimmune Diseases

    Science.gov (United States)

    Lintner, Katherine E.; Wu, Yee Ling; Yang, Yan; Spencer, Charles H.; Hauptmann, Georges; Hebert, Lee A.; Atkinson, John P.; Yu, C. Yung

    2016-01-01

    The complement system consists of effector proteins, regulators, and receptors that participate in host defense against pathogens. Activation of the complement system, via the classical pathway (CP), has long been recognized in immune complex-mediated tissue injury, most notably systemic lupus erythematosus (SLE). Paradoxically, a complete deficiency of an early component of the CP, as evidenced by homozygous genetic deficiencies reported in human, are strongly associated with the risk of developing SLE or a lupus-like disease. Similarly, isotype deficiency attributable to a gene copy-number (GCN) variation and/or the presence of autoantibodies directed against a CP component or a regulatory protein that result in an acquired deficiency are relatively common in SLE patients. Applying accurate assay methodologies with rigorous data validations, low GCNs of total C4, and heterozygous and homozygous deficiencies of C4A have been shown as medium to large effect size risk factors, while high copy numbers of total C4 or C4A as prevalent protective factors, of European and East-Asian SLE. Here, we summarize the current knowledge related to genetic deficiency and insufficiency, and acquired protein deficiencies for C1q, C1r, C1s, C4A/C4B, and C2 in disease pathogenesis and prognosis of SLE, and, briefly, for other systemic autoimmune diseases. As the complement system is increasingly found to be associated with autoimmune diseases and immune-mediated diseases, it has become an attractive therapeutic target. We highlight the recent developments and offer a balanced perspective concerning future investigations and therapeutic applications with a focus on early components of the CP in human systemic autoimmune diseases. PMID:26913032

  7. Mechanisms of complement activation by dextran-coated superparamagnetic iron oxide (SPIO) nanoworms in mouse versus human serum

    DEFF Research Database (Denmark)

    Banda, Nirmal K; Mehta, Gaurav; Chao, Ying

    2014-01-01

    BACKGROUND: The complement system is a key component of innate immunity implicated in the neutralization and clearance of invading pathogens. Dextran coated superparamagnetic iron oxide (SPIO) nanoparticle is a promising magnetic resonance imaging (MRI) contrast agent. However, dextran SPIO has...... the mechanisms of human complement activation. Mouse data were analyzed by non-paired t-test, human data were analyzed by ANOVA followed by multiple comparisons with Student-Newman-Keuls test. RESULTS: In mouse sera, SPIO NW triggered the complement activation via the LP, whereas the AP contributes via...... the CP, but that did not affect the total level of C3 deposition on the particles. CONCLUSIONS: There were important differences and similarities in the complement activation by SPIO NW in mouse versus human sera. Understanding the mechanisms of immune recognition of nanoparticles in mouse and human...

  8. Possible role of complement activation in renal impairment in trichloroethylene-sensitized guinea pigs

    International Nuclear Information System (INIS)

    Yu, Jun-Feng; Leng, Jing; Shen, Tong; Zhou, Cheng-Fan; Xu, Hui; Jiang, Tao; Xu, Shu-Hai; Zhu, Qi-Xing

    2012-01-01

    Recent studies have revealed that trichloroethylene (TCE) can induce occupational medicamentosa-like dermatitis (OMLD) with multi-system injuries, including liver, kidney and skin injuries, which can subsequently cause multiple organ failure later. But the mechanism of immune dysfunction leading to organ injury was rarely clarified. The present study was initiated to analyze the influence of trichloroethylene on renal injury and study the relevant mechanism in guinea pigs. Guinea pig maximization test (GPMT) was carried out. Inflammation on the guinea pigs’ skin was scored. Kidney function, urine protein and ultra-structural change of kidney were determined by biochemical detection and electron microscope. Deposition of complement 3 and membrane attack complex (MAC, C5b-9) were determined by immunohistochemistry. Erythema and edema of skin impairment were observed in TCE sensitized groups, and sensitization rate was 63.16%. Through electron microscope, tubular epithelial cell mitochondrial swelling, vacuolar degeneration and atrophy of microvillus were observed in TCE sensitized groups. The parameters of urease and urinary protein elevated markedly, and a high degree of C3 and MAC deposition was found in the renal tubular epithelial cells in TCE sensitized groups. By demonstrating that TCE and its metabolites can cause the deposition of C3 and MAC in renal epithelial cells, we found that activated complement system may be the mechanism of the acceleration and the development of TCE-induced kidney disease.

  9. Deposition of mannose-binding lectin and ficolins and activation of the lectin pathway of complement on the surface of polyurethane tubing used for cardiopulmonary bypass.

    Science.gov (United States)

    Eppa, Łukasz; Pągowska-Klimek, Izabela; Świerzko, Anna S; Moll, Maciej; Krajewski, Wojciech R; Cedzyński, Maciej

    2018-04-01

    The artificial surface used for cardiopulmonary bypass (CPB) is a crucial factor activating the complement system and thus contributing to the generation of a systemic inflammatory response. The activation of classical and alternative pathways on this artificial surface is well known. In contrast, lectin pathway (LP) activation has not been fully investigated, although noted during CPB in several studies. Moreover, we have recently proved the contribution of the LP to the generation of the systemic inflammatory response syndrome after pediatric cardiac surgery. The aim of this study was to assess LP-mediated complement activation on the surface of polyurethane CPB circuit tubing (noncoated Chalice ® ), used for CPB procedures in children with congenital heart disease. We found deposition of mannose-binding lectin, ficolin-1, -2, and -3 on the surface of unused tubing and on tubing used for CPB from a small minority of patients. Furthermore, we observed deposition of complement C4 activation products on tubing used for CPB and previously unused tubing after incubation with normal serum. The latter finding indicates LP activation in vitro on the polyurethane surface. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1202-1208, 2018. © 2017 Wiley Periodicals, Inc.

  10. Excretion of complement proteins and its activation marker C5b-9 in IgA nephropathy in relation to renal function

    Directory of Open Access Journals (Sweden)

    Onda Kisara

    2011-11-01

    Full Text Available Abstract Background Glomerular damage in IgA nephropathy (IgAN is mediated by complement activation via the alternative and lectin pathways. Therefore, we focused on molecules stabilizing and regulating the alternative pathway C3 convertase in urine which might be associated with IgAN pathogenesis. Methods Membrane attack complex (MAC, properdin (P, factor H (fH and Complement receptor type 1 (CR1 were quantified in urine samples from 71 patients with IgAN and 72 healthy controls. Glomerular deposition of C5, fH and P was assessed using an immunofluorescence technique and correlated with histological severity of IgAN and clinical parameters. Fibrotic changes and glomerular sclerosis were evaluated in renal biopsy specimens. Results Immunofluorescence studies revealed glomerular depositions of C5, fH and P in patients with IgAN. Urinary MAC, fH and P levels in IgAN patients were significantly higher than those in healthy controls (p Conclusions Complement activation occurs in the urinary space in IgAN and the measurement of levels of MAC and fH in the urine could be a useful indicator of renal injury in patients with IgAN.

  11. M-ficolin, an innate immune defence molecule, binds patterns of acetyl groups and activates complement

    DEFF Research Database (Denmark)

    Frederiksen, Pernille Dorthea; Thiel, Steffen; Larsen, Claus Bindslev

    2005-01-01

    Ficolins play a role in the innate immune defence as pathogen-associated molecular pattern recognition molecules. Three ficolins are found in humans: H-ficolin, L-ficolin and M-ficolin. L-ficolin and H-ficolin circulate in blood in complexes with mannan-binding lectin-associated serine proteases...... (MASPs) and are capable of activating the complement system. L-ficolin shows affinity for acetylated compounds and binds to various capsulated strains of bacteria. H-ficolin has been shown to bind Aerococcus viridans. Less is known about M-ficolin, but it is thought to be present only on monocytes. We...... system. We developed a monoclonal rat anti-human-M/L-ficolin antibody and verified by flow cytometric analysis the presence of ficolin on the surface of peripheral blood monocytes....

  12. Increased Autoreactivity of the Complement-Activating Molecule Mannan-Binding Lectin in a Type 1 Diabetes Model

    Directory of Open Access Journals (Sweden)

    Jakob Appel Østergaard

    2016-01-01

    Full Text Available Background. Diabetic kidney disease is the leading cause of end-stage renal failure despite intensive treatment of modifiable risk factors. Identification of new drug targets is therefore of paramount importance. The complement system is emerging as a potential new target. The lectin pathway of the complement system, initiated by the carbohydrate-recognition molecule mannan-binding lectin (MBL, is linked to poor kidney prognosis in diabetes. We hypothesized that MBL activates complement upon binding within the diabetic glomerulus. Methods. We investigated this by comparing complement deposition and activation in kidneys from streptozotocin-induced diabetic mice and healthy control mice. Results. After 20 weeks of diabetes, glomerular deposition of MBL was significantly increased. Diabetic animals had 2.0-fold higher (95% CI 1.6–2.5 immunofluorescence intensity from anti-MBL antibodies compared with controls (P<0.001. Diabetes and control groups did not differ in glomerular immunofluorescence intensity obtained by antibodies against complement factors C4, C3, and C9. However, the circulating complement activation product C3a was increased in diabetes as compared to control mice (P=0.04. Conclusion. 20 weeks of diabetes increased MBL autoreactivity in the kidney and circulating C3a concentration. Together with previous findings, these results indicate direct effects of MBL within the kidney in diabetes.

  13. Lupus anticoagulant, disease activity and low complement in the first trimester are predictive of pregnancy loss.

    Science.gov (United States)

    Mankee, Anil; Petri, Michelle; Magder, Laurence S

    2015-01-01

    Multiple factors, including proteinuria, antiphospholipid syndrome, thrombocytopenia and hypertension, are predictive of pregnancy loss in systemic lupus erythematosus (SLE). In the PROMISSE study of predictors of pregnancy loss, only a battery of lupus anticoagulant tests was predictive of a composite of adverse pregnancy outcomes. We examined the predictive value of one baseline lupus anticoagulant test (dilute Russell viper venom time) with pregnancy loss in women with SLE. From the Hopkins Lupus Cohort, there were 202 pregnancies from 175 different women after excluding twin pregnancies and pregnancies for which we did not have a first trimester assessment of lupus anticoagulant. We determined the percentage of women who had a pregnancy loss in groups defined by potential risk factors. The lupus anticoagulant was determined by dilute Russell viper venom time with appropriate mixing and confirmatory testing. Generalised estimating equations were used to calculate p values, accounting for repeated pregnancies in the same woman. The age at pregnancy was 40 (3%). 55% were Caucasian and 34% African-American. Among those with lupus anticoagulant during the first trimester, 6/16 (38%) experienced a pregnancy loss compared with only 16/186 (9%) of other pregnancies (p=0.003). In addition, those with low complement or higher disease activity had a higher rate of pregnancy loss than those without (p=0.049 and 0.005, respectively). In contrast, there was no association between elevated anticardiolipin in the first trimester and pregnancy loss. The strongest predictor of pregnancy loss in SLE in the first trimester is the lupus anticoagulant. In addition, moderate disease activity by the physician global assessment and low complement measured in the first trimester were predictive of pregnancy loss. These data suggest that treatment of the lupus anticoagulant could be considered, even in the absence of history of pregnancy loss.

  14. Bothrops asper snake venom and its metalloproteinase BaP–1 activate the complement system. Role in leucocyte recruitment

    Directory of Open Access Journals (Sweden)

    Sandra H. P. Farsky

    2000-01-01

    Full Text Available The venom of the snake Bothrops asper, the most important poisonous snake in Central America, evokes an inflammatory response, the mechanisms of which are not well characterized. The objectives of this study were to investigate whether B. asper venom and its purified toxins – phospholipases and metalloproteinase – activate the complement system and the contribution of the effect on leucocyte recruitment. In vitro chemotaxis assays were performed using Boyden's chamber model to investigate the ability of serum incubated with venom and its purified toxins to induce neutrophil migration. The complement consumption by the venom was evaluated using an in vitro haemolytic assay. The importance of complement activation by the venom on neutrophil migration was investigated in vivo by injecting the venom into the peritoneal cavity of C5-deficient mice. Data obtained demonstrated that serum incubated with crude venom and its purified metalloproteinase BaP–1 are able to induce rat neutrophil chemotaxis, probably mediated by agent(s derived from the complement system. This hypothesis was corroborated by the capacity of the venom to activate this system in vitro. The involvement of C5a in neutrophil chemotaxis induced by venom-activated serum was demonstrated by abolishing migration when neutrophils were pre-incubated with antirat C5a receptor antibody. The relevance of the complement system in in vivo leucocyte mobilization was further demonstrated by the drastic decrease of this response in C5-deficient mice. Pre-incubation of serum with the soluble human recombinant complement receptor type 1 (sCR 1 did not prevent the response induced by the venom, but abolished the migration evoked by metalloproteinase-activated serum. These data show the role of the complement system in bothropic envenomation and the participation of metalloproteinase in the effect. Also, they suggest that the venom may contain other component(s which can cause direct activation

  15. Specific, sensitive, precise, and rapid functional chromogenic assay of activated first complement component (C1) in plasma

    DEFF Research Database (Denmark)

    Munkvad, S; Jespersen, J; Sidelmann, Johannes Jakobsen

    1990-01-01

    We present a new functional assay for the first complement component (C1) in plasma, based on its activation by inhibition of the C1-esterase inhibitor (C1-inh) when monospecific antiserum to C1-inh is added to the plasma. After maximal activation, we can determine the concentration of activated ...

  16. Abnormal Complement Activation and Inflammation in the Pathogenesis of Retinopathy of Prematurity

    Directory of Open Access Journals (Sweden)

    Sonika Rathi

    2017-12-01

    Full Text Available Retinopathy of prematurity (ROP is a neurovascular complication in preterm babies, leading to severe visual impairment, but the underlying mechanisms are yet unclear. The present study aimed at unraveling the molecular mechanisms underlying the pathogenesis of ROP. A comprehensive screening of candidate genes in preterms with ROP (n = 189 and no-ROP (n = 167 was undertaken to identify variants conferring disease susceptibility. Allele and genotype frequencies, linkage disequilibrium and haplotypes were analyzed to identify the ROP-associated variants. Variants in CFH (p = 2.94 × 10−7, CFB (p = 1.71 × 10−5, FBLN5 (p = 9.2 × 10−4, CETP (p = 2.99 × 10−5, and CXCR4 (p = 1.32 × 10−8 genes exhibited significant associations with ROP. Further, a quantitative assessment of 27 candidate proteins and cytokines in the vitreous and tear samples of babies with severe ROP (n = 30 and congenital cataract (n = 30 was undertaken by multiplex bead arrays and further validated by western blotting and zymography. Significant elevation and activation of MMP9 (p = 0.038, CFH (p = 2.24 × 10−5, C3 (p = 0.05, C4 (p = 0.001, IL-1ra (p = 0.0019, vascular endothelial growth factor (VEGF (p = 0.0027, and G-CSF (p = 0.0099 proteins were observed in the vitreous of ROP babies suggesting an increased inflammation under hypoxic condition. Along with inflammatory markers, activated macrophage/microglia were also detected in the vitreous of ROP babies that secreted complement component C3, VEGF, IL-1ra, and MMP-9 under hypoxic stress in a cell culture model. Increased expression of the inflammatory markers like the IL-1ra (p = 0.014, MMP2 (p = 0.0085, and MMP-9 (p = 0.03 in the tears of babies at different stages of ROP further demonstrated their potential role in disease progression. Based on these findings, we conclude that increased complement activation in the

  17. The effect of storage temperature on the biological activity of extracellular vesicles for the complement system.

    Science.gov (United States)

    Park, Sang June; Jeon, Hyungtaek; Yoo, Seung-Min; Lee, Myung-Shin

    2018-05-10

    Extracellular vesicles (EVs) are mediators of intercellular communication by transporting cargo containing proteins, lipids, mRNA, and miRNA. There is increasing evidence that EVs have various roles in regulating migration, invasion, stemness, survival, and immune functions. Previously, we have found that EVs from Kaposi's sarcoma-associated herpesvirus (KSHV)-infected human endothelial cells have the potential to activate the complement system. Although many studies have shown that the physical properties of EVs can be changed by their storage condition, there have been few studies for the stability of biological activity of EVs in various storage conditions. In this study, we investigated various conditions to identify the best conditions to store EVs with functional stability for 25 d. Furthermore, the correlation between the function and other characteristics of EVs, including the expression of EV markers, size distribution, and particle number, were also analyzed. Our results demonstrated that storage temperature is an important factor to maintain the activity of EVs and would be useful information for basic research and clinical application using EVs.

  18. Complement activation and formation of the membrane attack complex on serogroup B Neisseria meningitidis in the presence or absence of serum bactericidal activity

    NARCIS (Netherlands)

    Drogari-Apiranthitou, M.; Kuijper, E. J.; Dekker, N. [=Nick; Dankert, J.

    2002-01-01

    Encapsulated meningococci are complement sensitive only in the presence of bactericidal antibodies by yet-unexplored mechanisms. The objective of this study was to investigate the involvement of major bacterial surface constituents on complement activation and membrane attack complex (MAC) formation

  19. Activation of the complement cascade enhances motility of leukemic cells by downregulating expression of HO-1.

    Science.gov (United States)

    Abdelbaset-Ismail, A; Borkowska-Rzeszotek, S; Kubis, E; Bujko, K; Brzeźniakiewicz-Janus, K; Bolkun, L; Kloczko, J; Moniuszko, M; Basak, G W; Wiktor-Jedrzejczak, W; Ratajczak, M Z

    2017-02-01

    As a crucial arm of innate immunity, the complement cascade (ComC) is involved both in mobilization of normal hematopoietic stem/progenitor cells (HSPCs) from bone marrow (BM) into peripheral blood and in their homing to BM. Despite the fact that ComC cleavage fragments alone do not chemoattract normal HSPCs, we found that leukemia cell lines as well as clonogenic blasts from chronic myeloid leukemia and acute myeloid leukemia patients respond robustly to C3 and C5 cleavage fragments by chemotaxis and increased adhesion. This finding was supported by the detection of C3a and C5a receptors in cells from human malignant hematopoietic cell lines and patient blasts at the mRNA (reverse transcriptase-polymerase chain reaction) and protein level (fluorescence-activated cell sorting), and by the demonstration that these receptors respond to stimulation by C3a and C5a by phosphorylation of p42/44 and p38 mitogen-activated protein kinases (MAPK), and protein kinase B (PKB/AKT). We also found that inducible heme oxygenase 1 (HO-1) is a negative regulator of ComC-mediated trafficking of leukemic cells, and that stimulation of leukemic cells by C3 or C5 cleavage fragments activates p38 MAPK, which downregulates HO-1 expression, rendering cells more mobile. We conclude that activation of the ComC in leukemia/lymphoma patients (for example, as a result of accompanying infections) enhances the motility of malignant cells and contributes to their spread in a p38 MAPK-HO-1-dependent manner. Therefore, inhibition of p38 MAPK or upregulation of HO-1 by small-molecule modulators would have a beneficial effect on ameliorating cell migration-mediated expansion of leukemia/lymphoma cells when the ComC becomes activated.

  20. Activation of the complement cascade enhances motility of leukemic cells by downregulating expression of HO-1

    Science.gov (United States)

    Abdelbaset-Ismail, A; Borkowska-Rzeszotek, S; Kubis, E; Bujko, K; Brzeźniakiewicz-Janus, K; Bolkun, L; Kloczko, J; Moniuszko, M; Basak, G W; Wiktor-Jedrzejczak, W; Ratajczak, M Z

    2017-01-01

    As a crucial arm of innate immunity, the complement cascade (ComC) is involved both in mobilization of normal hematopoietic stem/progenitor cells (HSPCs) from bone marrow (BM) into peripheral blood and in their homing to BM. Despite the fact that ComC cleavage fragments alone do not chemoattract normal HSPCs, we found that leukemia cell lines as well as clonogenic blasts from chronic myeloid leukemia and acute myeloid leukemia patients respond robustly to C3 and C5 cleavage fragments by chemotaxis and increased adhesion. This finding was supported by the detection of C3a and C5a receptors in cells from human malignant hematopoietic cell lines and patient blasts at the mRNA (reverse transcriptase-polymerase chain reaction) and protein level (fluorescence-activated cell sorting), and by the demonstration that these receptors respond to stimulation by C3a and C5a by phosphorylation of p42/44 and p38 mitogen-activated protein kinases (MAPK), and protein kinase B (PKB/AKT). We also found that inducible heme oxygenase 1 (HO-1) is a negative regulator of ComC-mediated trafficking of leukemic cells, and that stimulation of leukemic cells by C3 or C5 cleavage fragments activates p38 MAPK, which downregulates HO-1 expression, rendering cells more mobile. We conclude that activation of the ComC in leukemia/lymphoma patients (for example, as a result of accompanying infections) enhances the motility of malignant cells and contributes to their spread in a p38 MAPK–HO-1-dependent manner. Therefore, inhibition of p38 MAPK or upregulation of HO-1 by small-molecule modulators would have a beneficial effect on ameliorating cell migration-mediated expansion of leukemia/lymphoma cells when the ComC becomes activated. PMID:27451975

  1. Decreased material-activation of the complement system using low-energy plasma polymerized poly(vinyl pyrrolidone) coatings

    DEFF Research Database (Denmark)

    Andersen, T.E.; Kolmos, H.J.; Palarasah, Yaseelan

    2011-01-01

    In the current study we investigate the activation of blood complement on medical device silicone rubber and present a plasma polymerized vinyl pyrrolidone (ppVP) coating which strongly decreases surface-activation of the blood complement system. We show that uncoated silicone and polystyrene...... surface. The ppVP surface is furthermore characterized physically and chemically using scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR), which indicates preservation of chemical functionality by the applied plasma process. Overall, the pp...

  2. Level of complement activity predicts cardiac dysfunction after acute myocardial infarction treated with primary percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Haahr-Pedersen, Sune; Bjerre, Mette; Flyvbjerg, Allan

    2009-01-01

    BACKGROUND: The positive effect of reperfusion after ST-elevation myocardial infarction (STEMI) can be reduced by ischemic/reperfusion (I/R) injury.Mannose-binding-lectin (MBL) and soluble C5b-9 (membrane-attack-complex) are involved in complement-driven cell lysis and may play a role in human...... with increased risk of cardiac dysfunction in STEMI patients treated with pPCI, probably due to increased complement activity during the ischemic and reperfusion process. The predictive value of low peripheral plasma sC5b-9 may be explained by an accumulation and activation of sC5b-9 in the infarcted myocardium....

  3. A Revised Mechanism for the Activation of Complement C3 to C3b

    Science.gov (United States)

    Rodriguez, Elizabeth; Nan, Ruodan; Li, Keying; Gor, Jayesh; Perkins, Stephen J.

    2015-01-01

    The solution structure of complement C3b is crucial for the understanding of complement activation and regulation. C3b is generated by the removal of C3a from C3. Hydrolysis of the C3 thioester produces C3u, an analog of C3b. C3b cleavage results in C3c and C3d (thioester-containing domain; TED). To resolve functional questions in relation to C3b and C3u, analytical ultracentrifugation and x-ray and neutron scattering studies were used with C3, C3b, C3u, C3c, and C3d, using the wild-type allotype with Arg102. In 50 mm NaCl buffer, atomistic scattering modeling showed that both C3b and C3u adopted a compact structure, similar to the C3b crystal structure in which its TED and macroglobulin 1 (MG1) domains were connected through the Arg102–Glu1032 salt bridge. In physiological 137 mm NaCl, scattering modeling showed that C3b and C3u were both extended in structure, with the TED and MG1 domains now separated by up to 6 nm. The importance of the Arg102–Glu1032 salt bridge was determined using surface plasmon resonance to monitor the binding of wild-type C3d(E1032) and mutant C3d(A1032) to immobilized C3c. The mutant did not bind, whereas the wild-type form did. The high conformational variability of TED in C3b in physiological buffer showed that C3b is more reactive than previously thought. Because the Arg102-Glu1032 salt bridge is essential for the C3b-Factor H complex during the regulatory control of C3b, the known clinical associations of the major C3S (Arg102) and disease-linked C3F (Gly102) allotypes of C3b were experimentally explained for the first time. PMID:25488663

  4. Oral vaccination with heat inactivated Mycobacterium bovis activates the complement system to protect against tuberculosis.

    Directory of Open Access Journals (Sweden)

    Beatriz Beltrán-Beck

    Full Text Available Tuberculosis (TB remains a pandemic affecting billions of people worldwide, thus stressing the need for new vaccines. Defining the correlates of vaccine protection is essential to achieve this goal. In this study, we used the wild boar model for mycobacterial infection and TB to characterize the protective mechanisms elicited by a new heat inactivated Mycobacterium bovis vaccine (IV. Oral vaccination with the IV resulted in significantly lower culture and lesion scores, particularly in the thorax, suggesting that the IV might provide a novel vaccine for TB control with special impact on the prevention of pulmonary disease, which is one of the limitations of current vaccines. Oral vaccination with the IV induced an adaptive antibody response and activation of the innate immune response including the complement component C3 and inflammasome. Mycobacterial DNA/RNA was not involved in inflammasome activation but increased C3 production by a still unknown mechanism. The results also suggested a protective mechanism mediated by the activation of IFN-γ producing CD8+ T cells by MHC I antigen presenting dendritic cells (DCs in response to vaccination with the IV, without a clear role for Th1 CD4+ T cells. These results support a role for DCs in triggering the immune response to the IV through a mechanism similar to the phagocyte response to PAMPs with a central role for C3 in protection against mycobacterial infection. Higher C3 levels may allow increased opsonophagocytosis and effective bacterial clearance, while interfering with CR3-mediated opsonic and nonopsonic phagocytosis of mycobacteria, a process that could be enhanced by specific antibodies against mycobacterial proteins induced by vaccination with the IV. These results suggest that the IV acts through novel mechanisms to protect against TB in wild boar.

  5. Effect of b-Propiolactone treatment on the complement activation mediated by equine antisera

    Directory of Open Access Journals (Sweden)

    Rosalvo GUIDOLIN

    1997-03-01

    Full Text Available Reduction of complement activation through an alteration of the Fc fragment of immunoglobulins by b-propiolactone treatment was carried out in equine antisera raised against rabies virus, Bothrops venoms and diphtherial toxin. Results were evaluated by means of an anaphylactic test performed on guinea-pigs, and compared to the ones obtained with the same sera purified by saline precipitation (ammonium sulfate, followed or not by enzymatic digestion with pepsin. Protein purity levels for antibothropic serum were 184.5 mg/g and 488.5 mg/g in b-propiolactone treated and pepsin-digested sera, respectively. The recovery of specific activity was 100% and 62.5% when using antibothropic serum treated by b-propiolactone and pepsin digestion, respectively. The antidiphtherial and anti-rabies sera treated with b-propiolactone and pepsin presented protein purity levels of 5,698 and 7,179 Lf/g, 16,233 and 6,784 IU/g, respectively. The recovery of specific activity for these antisera were 88.8%, 77.7%, 100% and 36,5%, respectively. b-propiolactone treatment induced a reduction in complement activation, tested "in vivo", without significant loss of biological activity. This treatment can be used in the preparation of heterologous immunoglobulins for human use.Efeito do tratamento de antissoros equinos pela b-propiolactona na ativação do complemento. A redução da ativação do complemento através de uma alteração do fragmento Fc das imunoglobulinas pela b-propiolactona foi obtida em soros hiperimunes equinos antivirus rábico, venenos Bothrops e toxina diftérica. Os resultados foram avaliados por teste de anafilaxia em cobaias, e comparados com aqueles obtidos com os mesmos soros purificados por precipitação salina (sulfato de amônio, seguidos ou não por digestão enzimática com pepsina. Os níveis de pureza protéica foram para o soro antibotrópico de 184.5 mg/g e 488.5 mg/g tratado pela b-propiolactona e digeridos pela pepsina, respectivamente

  6. Thrombin activatable fibrinolysis inhibitor (TAFI) - A possible link between coagulation and complement activation in the antiphospholipid syndrome (APS).

    Science.gov (United States)

    Grosso, Giorgia; Vikerfors, Anna; Woodhams, Barry; Adam, Mariette; Bremme, Katarina; Holmström, Margareta; Ågren, Anna; Eelde, Anna; Bruzelius, Maria; Svenungsson, Elisabet; Antovic, Aleksandra

    2017-10-01

    Thrombosis and complement activation are pathogenic features of antiphospholipid syndrome (APS). Their molecular link is Plasma carboxypeptidase-B, also known as thrombin activatable fibrinolysis inhibitor (TAFIa), which plays a dual role: anti-fibrinolytic, by cleaving carboxyl-terminal lysine residues from partially degraded fibrin, and anti-inflammatory, by downregulating complement anaphylatoxins C3a and C5a. To investigate the levels of TAFI (proenzyme) and TAFIa (active enzyme) in relation to complement activation, fibrin clot permeability and fibrinolytic function in clinical and immunological subsets of 52 APS patients and 15 controls. TAFI (pAPS patients compared to controls. Furthermore, TAFIa was increased (pAPS patients affected by arterial thrombosis compared to other APS-phenotypes. Positive associations were found between TAFI and age, fibrinogen and C5a, and between TAFIa and age, fibrinogen and thrombomodulin. TAFI and TAFIa levels were increased in patients with APS as a potential response to complement activation. Interestingly, TAFI activation was associated with arterial thrombotic APS manifestations. Thus, TAFIa may be considered a novel biomarker for arterial thrombosis in APS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Increased activity of the mannan-binding lectin complement activation pathway in patients with colorectal cancer

    DEFF Research Database (Denmark)

    Ytting, H; Jensenius, Jens Christian; Christensen, I J

    2004-01-01

    in certain patient groups. It is hypothesized that a deficient MBL pathway might be more frequent among patients with CRC than in healthy individuals. The MBL pathway was therefore evaluated in serum obtained preoperatively from 193 patients with primary CRC and in serum from 150 healthy volunteers. METHODS......: Serum MBL concentrations and MBL/MASP activity were determined using immunofluorometric assays. The levels are presented as the median, inter-quartile range and range. RESULTS: Serum MBL levels were significantly (P ..., inter-quartile range) compared with levels in healthy blood donors (924 (230-1476) ng/mL). Similarly, the MBL/MASP activity was significantly (P age, gender, tumour location...

  8. (IgA, IgG and IgM) levels and complement fixation activity in HIV

    African Journals Online (AJOL)

    The study was designed to evaluate the immunoglobulin A, G and M levels and complement fixation activity in HIV infected participants, who were not administered antiretroviral therapy (ART). Eighty (80) HIV infected participants, aged between 15 – 55 years (38 ±10 years), were recruited for the study. Forty five (45) of the ...

  9. Retinal pigment epithelial cells upregulate expression of complement factors after co-culture with activated T cells

    DEFF Research Database (Denmark)

    Juel, Helene Bæk; Kaestel, Charlotte; Folkersen, Lasse

    2011-01-01

    In this study we examined the effect of T cell-derived cytokines on retinal pigment epithelial (RPE) cells with respect to expression of complement components. We used an in vitro co-culture system in which CD3/CD28-activated human T cells were separated from the human RPE cell line (ARPE-19...

  10. A systematic analysis of the complement pathways in patients with neuromyelitis optica indicates alteration but no activation during remission

    DEFF Research Database (Denmark)

    Veszeli, Nóra; Füst, György; Csuka, Dorottya

    2014-01-01

    Neuromyelitis optica (NMO) is an autoimmune demyelinating inflammatory disorder, mediated by pathogenic autoantibodies against aquaporin 4 (AQP4), the main water channel of the central nervous system (CNS). NMO is characterized by local IgG deposition and complement activation within the CNS...

  11. Immune response to snake envenoming and treatment with antivenom; complement activation, cytokine production and mast cell degranulation.

    Directory of Open Access Journals (Sweden)

    Shelley F Stone

    Full Text Available BACKGROUND: Snake bite is one of the most neglected public health issues in poor rural communities worldwide. In addition to the clinical effects of envenoming, treatment with antivenom frequently causes serious adverse reactions, including hypersensitivity reactions (including anaphylaxis and pyrogenic reactions. We aimed to investigate the immune responses to Sri Lankan snake envenoming (predominantly by Russell's viper and antivenom treatment. METHODOLOGY/PRINCIPAL FINDINGS: Plasma concentrations of Interleukin (IL-6, IL-10, tumor necrosis factor α (TNFα, soluble TNF receptor I (sTNFRI, anaphylatoxins (C3a, C4a, C5a; markers of complement activation, mast cell tryptase (MCT, and histamine were measured in 120 Sri Lankan snakebite victims, both before and after treatment with antivenom. Immune mediator concentrations were correlated with envenoming features and the severity of antivenom-induced reactions including anaphylaxis. Envenoming was associated with complement activation and increased cytokine concentrations prior to antivenom administration, which correlated with non-specific systemic symptoms of envenoming but not with coagulopathy or neurotoxicity. Typical hypersensitivity reactions to antivenom occurred in 77/120 patients (64%, satisfying criteria for a diagnosis of anaphylaxis in 57/120 (48%. Pyrogenic reactions were observed in 32/120 patients (27%. All patients had further elevations in cytokine concentrations, but not complement activation, after the administration of antivenom, whether a reaction was noted to occur or not. Patients with anaphylaxis had significantly elevated concentrations of MCT and histamine. CONCLUSIONS/SIGNIFICANCE: We have demonstrated that Sri Lankan snake envenoming is characterized by significant complement activation and release of inflammatory mediators. Antivenom treatment further enhances the release of inflammatory mediators in all patients, with anaphylactic reactions characterised by high

  12. Mechanisms of evasion of Schistosoma mansoni schistosomula to the lethal activity of complement

    Directory of Open Access Journals (Sweden)

    F. Juarez Ramalho-Pinto

    1992-01-01

    Full Text Available Schistosomula of Schistosoma mansoni became resistant to antibody-dependent complement damage in vitro after pre-incubation with normal human erythrocytes (NHuE whatever the ABO or Rh blood group. Resistant parasites were shown to acquire host decay accelerating factor (DAF , a 70 kDa glycoprotein attached to the membrane of NHue by a GPI anchor. IgG2a mAb anti-human DAF (IA10 immunoprecipitated a 70 kDa molecule from 125I-labeled schistosomula pre-incubated with NHuE and inhibited their resistance to complement-dependent killing in vtro. Incubationof schistosomula with erytrocytes from patients with paroxsimal nocturnal hemoglobinuria (PNHE or SRBC, wich are DAF-deficient, did not protect the parasites from complement lesion. Supernatant of 100,000 x g collected from NHuE incubated for 24 h in defined medium was shown to contain a soluble form of DAF and to protect schistosomula from complement killing. Schistosomula treated with trypsin before incubation with NHuE ghosts did not become resistant to complement damage. On the other hand, pre-treatment with chymotrypsin did not interfere with the acquisition of resistance by the schistosomula. These results indicate that, in vitro, NHuE DAF can be transferred to schistosomula in a soluble form and that the binding of this molecule to the parasite surface is dependent upon trypsin-sensitive chymotrypsin-insensitive polipeptide(s present on the surface of the worm.

  13. Complement activation on the surface of cell-derived microparticles during cardiac surgery with cardiopulmonary bypass - is retransfusion of pericardial blood harmful?

    Science.gov (United States)

    Biró, E; van den Goor, J M; de Mol, B A; Schaap, M C; Ko, L-Y; Sturk, A; Hack, C E; Nieuwland, R

    2011-01-01

    To investigate whether cell-derived microparticles play a role in complement activation in pericardial blood of patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) and whether microparticles in pericardial blood contribute to systemic complement activation upon retransfusion. Pericardial blood of 13 patients was retransfused in 9 and discarded in 4 cases. Microparticles were isolated from systemic blood collected before anesthesia (T1) and at the end of CPB (T2), and from pericardial blood. The microparticles were analyzed by flow cytometry for bound complement components C1q, C4 and C3, and bound complement activator molecules C-reactive protein (CRP), serum amyloid P-component (SAP), immunoglobulin (Ig)M and IgG. Fluid-phase complement activation products (C4b/c, C3b/c) and activator molecules were determined by ELISA. Compared with systemic T1 blood, pericardial blood contained increased C4b/c and C3b/c, and increased levels of microparticles with bound complement components. In systemic T1 samples, microparticle-bound CRP, whereas in pericardial blood, microparticle-bound SAP and IgM were associated with complement activation. At the end of CPB, increased C3b/c (but not C4b/c) was present in systemic T2 blood compared with T1, while concentrations of microparticles binding complement components and of those binding complement activator molecules were similar. Concentrations of fluid-phase complement activation products and microparticles were similar in patients whether or not retransfused with pericardial blood. In pericardial blood of patients undergoing cardiac surgery with CPB, microparticles contribute to activation of the complement system via bound SAP and IgM. Retransfusion of pericardial blood, however, does not contribute to systemic complement activation.

  14. Preparation of Low Molecular Weight Chondroitin Sulfates, Screening of a High Anti-Complement Capacity of Low Molecular Weight Chondroitin Sulfate and Its Biological Activity Studies in Attenuating Osteoarthritis.

    Science.gov (United States)

    Li, Lian; Li, Yan; Feng, Danyang; Xu, Linghua; Yin, Fengxin; Zang, Hengchang; Liu, Chunhui; Wang, Fengshan

    2016-10-11

    Chondroitin sulfate (CS) plays important roles in the complement system. However, the CS structure is complicated due to different sources and the number and positions of sulfate groups. The objective of this study was to prepare different low molecular weight chondroitin sulfates (LMWCSs) and to investigate the biological activity in anti-complement capacity. A series of LMWCSs was prepared from different sources and characterized by ultraviolet-visible (UV) spectroscopy, high-performance liquid chromatography (HPLC), size exclusion chromatography-multiangle laser light scattering (SEC-MALLS) and nuclear magnetic resonance (NMR) spectroscopy. Hemolytic, anti-complement 3 deposition capacity and cell viability assays were carried out to investigate the biological activities in vitro. The results showed that LMWCS prepared from shark cartilage with the oxidative degradation method (LMWCS-S-O) had the best anti-complement capacity. LMWCS-S-O could inhibit the alternative pathway of the complement system and protect chondrocytes from cell death. The attenuating effect of LMWCS-S-O on Osteoarthritis (OA) was investigated by destabilization of the medial meniscus (DMM) model in vivo. Functional wind-up, histological and C5b-9 analyses were used to evaluate the treatment effect on the OA model. In vivo results showed that LMWCS-S-O could attenuate OA. LMWCS-S-O with a high content of ΔDi-2,6diS and ΔDi-6S could be used for attenuating OA through regulating the complement system.

  15. Preparation of Low Molecular Weight Chondroitin Sulfates, Screening of a High Anti-Complement Capacity of Low Molecular Weight Chondroitin Sulfate and Its Biological Activity Studies in Attenuating Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Lian Li

    2016-10-01

    Full Text Available Chondroitin sulfate (CS plays important roles in the complement system. However, the CS structure is complicated due to different sources and the number and positions of sulfate groups. The objective of this study was to prepare different low molecular weight chondroitin sulfates (LMWCSs and to investigate the biological activity in anti-complement capacity. A series of LMWCSs was prepared from different sources and characterized by ultraviolet-visible (UV spectroscopy, high-performance liquid chromatography (HPLC, size exclusion chromatography-multiangle laser light scattering (SEC-MALLS and nuclear magnetic resonance (NMR spectroscopy. Hemolytic, anti-complement 3 deposition capacity and cell viability assays were carried out to investigate the biological activities in vitro. The results showed that LMWCS prepared from shark cartilage with the oxidative degradation method (LMWCS-S-O had the best anti-complement capacity. LMWCS-S-O could inhibit the alternative pathway of the complement system and protect chondrocytes from cell death. The attenuating effect of LMWCS-S-O on Osteoarthritis (OA was investigated by destabilization of the medial meniscus (DMM model in vivo. Functional wind-up, histological and C5b-9 analyses were used to evaluate the treatment effect on the OA model. In vivo results showed that LMWCS-S-O could attenuate OA. LMWCS-S-O with a high content of ΔDi-2,6diS and ΔDi-6S could be used for attenuating OA through regulating the complement system.

  16. Complement activation in Ghanaian children with severe Plasmodium falciparum malaria

    DEFF Research Database (Denmark)

    Helegbe, Gideon K; Goka, Bamenla Q; Kurtzhals, Jørgen

    2007-01-01

    BACKGROUND: Severe anaemia (SA), intravascular haemolysis (IVH) and respiratory distress (RD) are severe forms of Plasmodium falciparum malaria, with RD reported to be of prognostic importance in African children with malarial anaemia. Complement factors have been implicated in the mechanism lead...

  17. Split-Cre complementation restores combination activity on transgene excision in hair roots of transgenic tobacco.

    Directory of Open Access Journals (Sweden)

    Mengling Wen

    Full Text Available The Cre/loxP system is increasingly exploited for genetic manipulation of DNA in vitro and in vivo. It was previously reported that inactive ''split-Cre'' fragments could restore Cre activity in transgenic mice when overlapping co-expression was controlled by two different promoters. In this study, we analyzed recombination activities of split-Cre proteins, and found that no recombinase activity was detected in the in vitro recombination reaction in which only the N-terminal domain (NCre of split-Cre protein was expressed, whereas recombination activity was obtained when the C-terminal (CCre or both NCre and CCre fragments were supplied. We have also determined the recombination efficiency of split-Cre proteins which were co-expressed in hair roots of transgenic tobacco. No Cre recombination event was observed in hair roots of transgenic tobacco when the NCre or CCre genes were expressed alone. In contrast, an efficient recombination event was found in transgenic hairy roots co-expressing both inactive split-Cre genes. Moreover, the restored recombination efficiency of split-Cre proteins fused with the nuclear localization sequence (NLS was higher than that of intact Cre in transgenic lines. Thus, DNA recombination mediated by split-Cre proteins provides an alternative method for spatial and temporal regulation of gene expression in transgenic plants.

  18. Surviving mousepox infection requires the complement system.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Moulton

    2008-12-01

    Full Text Available Poxviruses subvert the host immune response by producing immunomodulatory proteins, including a complement regulatory protein. Ectromelia virus provides a mouse model for smallpox where the virus and the host's immune response have co-evolved. Using this model, our study investigated the role of the complement system during a poxvirus infection. By multiple inoculation routes, ectromelia virus caused increased mortality by 7 to 10 days post-infection in C57BL/6 mice that lack C3, the central component of the complement cascade. In C3(-/- mice, ectromelia virus disseminated earlier to target organs and generated higher peak titers compared to the congenic controls. Also, increased hepatic inflammation and necrosis correlated with these higher tissue titers and likely contributed to the morbidity in the C3(-/- mice. In vitro, the complement system in naïve C57BL/6 mouse sera neutralized ectromelia virus, primarily through the recognition of the virion by natural antibody and activation of the classical and alternative pathways. Sera deficient in classical or alternative pathway components or antibody had reduced ability to neutralize viral particles, which likely contributed to increased viral dissemination and disease severity in vivo. The increased mortality of C4(-/- or Factor B(-/- mice also indicates that these two pathways of complement activation are required for survival. In summary, the complement system acts in the first few minutes, hours, and days to control this poxviral infection until the adaptive immune response can react, and loss of this system results in lethal infection.

  19. Global Autorecognition and Activation of Complement by Mannan-Binding Lectin in a Mouse Model of Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Esben Axelgaard

    2017-01-01

    Full Text Available Increasing evidence links mannan-binding lectin (MBL to late vascular complications of diabetes. MBL is a complement-activating pattern recognition molecule of the innate immune system that can mediate an inflammation response through activation of the lectin pathway. In two recent animal studies, we have shown that autoreactivity of MBL is increased in the kidney in diabetic nephropathy. We hypothesize that long-term exposure to uncontrolled high blood glucose in diabetes may mediate formation of neoepitopes in several tissues and that MBL is able to recognize these structures and thus activate the lectin pathway. To test this hypothesis, we induced diabetes by injection of low-dose streptozotocin in MBL double-knockout (MBL/DKO mice. Development of diabetes was followed by measurements of blood glucose and urine albumin-to-creatinine ratio. Fluorophore-labelled recombinant MBL was injected intravenously in diabetic and nondiabetic mice followed by ex vivo imaging of several organs. We observed that MBL accumulated in the heart, liver, brain, lung, pancreas, and intestines of diabetic mice. We furthermore detected increased systemic complement activation after administration of MBL, thus indicating MBL-mediated systemic complement activation in these animals. These new findings indicate a global role of MBL during late diabetes-mediated vascular complications in various tissues.

  20. Lectin complement pathway gene profile of the donor and recipient does not influence graft outcome after kidney transplantation.

    NARCIS (Netherlands)

    Damman, J.; Kok, J.L.; Snieder, H.; Leuvenink, H.G.; Goor, H. van; Hillebrands, J.L.; Dijk, M.C.R.F. van; Hepkema, B.G.; Reznichenko, A.; Born, J. van den; Borst, M.H. de; Bakker, S.J.; Navis, G.J.; Ploeg, R.J.; Seelen, M.A.

    2012-01-01

    In kidney transplantation, complement activation was found to be induced by donor brain death, renal ischemia-reperfusion injury and allograft rejection. There are three known pathways of complement activation: the classical, lectin and the alternative pathway. The lectin complement pathway can be

  1. In Situ complement activation and T-cell immunity in leprosy spectrum: An immunohistological study on leprosy lesional skin.

    Science.gov (United States)

    Bahia El Idrissi, Nawal; Iyer, Anand M; Ramaglia, Valeria; Rosa, Patricia S; Soares, Cleverson T; Baas, Frank; Das, Pranab K

    2017-01-01

    Mycobacterium leprae (M. leprae) infection causes nerve damage and the condition worsens often during and long after treatment. Clearance of bacterial antigens including lipoarabinomannan (LAM) during and after treatment in leprosy patients is slow. We previously demonstrated that M. leprae LAM damages peripheral nerves by in situ generation of the membrane attack complex (MAC). Investigating the role of complement activation in skin lesions of leprosy patients might provide insight into the dynamics of in situ immune reactivity and the destructive pathology of M. leprae. In this study, we analyzed in skin lesions of leprosy patients, whether M. leprae antigen LAM deposition correlates with the deposition of complement activation products MAC and C3d on nerves and cells in the surrounding tissue. Skin biopsies of paucibacillary (n = 7), multibacillary leprosy patients (n = 7), and patients with erythema nodosum leprosum (ENL) (n = 6) or reversal reaction (RR) (n = 4) and controls (n = 5) were analyzed. The percentage of C3d, MAC and LAM deposition was significantly higher in the skin biopsies of multibacillary compared to paucibacillary patients (p = leprosy patients (r = 0.9578, pleprosy patients (p = leprosy patients, suggesting that inflammation driven by complement activation might contribute to nerve damage in the lesions of these patients. This should be regarded as an important factor in M. leprae nerve damage pathology.

  2. Renewable energies, alternative or complement?; Energie renouvelables, alternative ou complement?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-05-01

    This meeting deals with the place of the renewable energies in the future. Many subjects were discussed during this meeting: the renewable energies part in in the heating systems and in the bio-fuels, the development of the solar and the wind power energies, the choice of a sector to assist, the renewable energies and the economic development. The full texts of the presentations are provided. (A.L.B.)

  3. Complement Test

    Science.gov (United States)

    ... Salicylates Semen Analysis Serotonin Serum Free Light Chains Sex Hormone Binding Globulin (SHBG) Shiga toxin-producing Escherichia ... and forming complexes that respond to infections, non-self tissues (transplants), dead cells ... KJ. Complement determinations in human disease. Ann Allergy Asthma Immunol . 2004; ...

  4. Early decrease in total hemolytic complement activity (CH100) after fasting or intestinal bypass in the rat.

    Science.gov (United States)

    Montanari, M; Violi, V; Muri, M; Roncoroni, L; Mora, G; Ronzoni, M

    1986-01-01

    An evaluation of total hemolytic complement activity (CH100) after fasting or intestinal bypass was performed in rats. The experiment lasted 6 days. Three groups, of 5 animals each, were studied. On the 1st day, basal values of total complement (TC), albumin and body weight were determined. Group A received normal, ad libitum feeding, group B started on a 'water only' diet, group C underwent intestinal bypass. On the 4th and 6th day the parameters were assessed. TC mean values were significantly lower in groups B and C, as compared to group A, on the 4th as well as on the 6th day (p less than 0.01 by Mann-Whitney's U test). Body weight showed a similar trend. Differences in albumin were never statistically significant. Limitations of the analytical method are discussed. The data show that fasting or bypass-induced malabsorption may determine an early decrease in total hemolytic complement activity, though a development of an immune deficiency is not proved.

  5. Treatment of platelets with riboflavin and ultraviolet light mediates complement activation and suppresses monocyte interleukin-12 production in whole blood.

    Science.gov (United States)

    Loh, Y S; Dean, M M; Johnson, L; Marks, D C

    2015-11-01

    Pathogen inactivation (PI) and storage may alter the immunomodulatory capacity of platelets (PLTs). The aim of this study was to examine the effect of PI (Riboflavin and ultraviolet light treatment) and storage on the capacity of PLTs to induce cytokine responses in recipient inflammatory cells. A pool and split design was used to prepare untreated and PI-treated buffy coat-derived platelet concentrates (PCs). Samples were taken on days 2 and 7 postcollection and incubated with ABO/RhD-matched fresh whole blood for 6 h with or without lipopolysaccharide (LPS). The intracellular production of IP-10, MCP-1, MIP-1α, IL-8, IL-6, IL-10, IL-12, TNF-α and MIP-1β in monocytes and neutrophils was assessed using flow cytometry. Complement proteins in PLT supernatants were measured using a cytometric bead array. PLTs and PLT supernatant (both untreated and PI-treated) resulted in modulation of intracellular MIP-1β and IL-12 production in monocytes. Compared to untreated PLTs, PI-treated PLTs resulted in significantly lower LPS-induced monocyte IL-12 production (day 7). The concentration of C3a and C5a (and their desArg forms) was significantly increased in PLT supernatants following PI. PI results in decreased LPS-induced monocyte IL-12 production and increased complement activation. The association between platelet-induced complement activation and IL-12 production warrants further investigation. © 2015 International Society of Blood Transfusion.

  6. Complement activation as a bioequivalence issue relevant to the development of generic liposomes and other nanoparticulate drugs

    International Nuclear Information System (INIS)

    Szebeni, Janos; Storm, Gert

    2015-01-01

    Liposomes are known to activate the complement (C) system, which can lead in vivo to a hypersensitivity syndrome called C activation-related pseudoallergy (CARPA). CARPA has been getting increasing attention as a safety risk of i.v. therapy with liposomes, whose testing is now recommended in bioequivalence evaluations of generic liposomal drug candidates. This review highlights the adverse consequences of C activation, the unique symptoms of CARPA triggered by essentially all i.v. administered liposomal drugs, and the various features of vesicles influencing this adverse immune effect. For the case of Doxil, we also address the mechanism of C activation and the opsonization vs. long circulation (stealth) paradox. In reviewing the methods of assessing C activation and CARPA, we delineate the most sensitive porcine model and an algorithm for stepwise evaluation of the CARPA risk of i.v. liposomes, which are proposed for standardization for preclinical toxicology evaluation of liposomal and other nanoparticulate drug candidates. - Highlights: • Outlining of difficulties in generic development of liposomal drugs. • New regulatory requirements to evaluate CARPA in preclinical studies. • Review of complement activation by liposomes and its adverse consequences (CARPA). • Assays of C activation in vitro and CARPA in vivo, with the porcine test in focus. • Decision tree how to handle the risk of CARPA assessed by a battery of tests.

  7. Complement activation as a bioequivalence issue relevant to the development of generic liposomes and other nanoparticulate drugs

    Energy Technology Data Exchange (ETDEWEB)

    Szebeni, Janos, E-mail: jszebeni2@gmail.com [Nanomedicine Research and Education Center, Semmelweis University, Budapest & SeroScience Ltd, Budapest (Hungary); Storm, Gert [Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, Utrecht (Netherlands)

    2015-12-18

    Liposomes are known to activate the complement (C) system, which can lead in vivo to a hypersensitivity syndrome called C activation-related pseudoallergy (CARPA). CARPA has been getting increasing attention as a safety risk of i.v. therapy with liposomes, whose testing is now recommended in bioequivalence evaluations of generic liposomal drug candidates. This review highlights the adverse consequences of C activation, the unique symptoms of CARPA triggered by essentially all i.v. administered liposomal drugs, and the various features of vesicles influencing this adverse immune effect. For the case of Doxil, we also address the mechanism of C activation and the opsonization vs. long circulation (stealth) paradox. In reviewing the methods of assessing C activation and CARPA, we delineate the most sensitive porcine model and an algorithm for stepwise evaluation of the CARPA risk of i.v. liposomes, which are proposed for standardization for preclinical toxicology evaluation of liposomal and other nanoparticulate drug candidates. - Highlights: • Outlining of difficulties in generic development of liposomal drugs. • New regulatory requirements to evaluate CARPA in preclinical studies. • Review of complement activation by liposomes and its adverse consequences (CARPA). • Assays of C activation in vitro and CARPA in vivo, with the porcine test in focus. • Decision tree how to handle the risk of CARPA assessed by a battery of tests.

  8. Structural features and complement-fixing activity of pectin from three Brassica oleracea varieties: white cabbage, kale, and red kale.

    Science.gov (United States)

    Samuelsen, Anne Berit; Westereng, Bjørge; Yousif, Osman; Holtekjølen, Ann Katrin; Michaelsen, Terje E; Knutsen, Svein H

    2007-02-01

    Leaves of different cabbage species are used both as food and as wound healing remedies in traditional medicine. This supposed wound healing activity might be connected to presence of immunomodulating water soluble polysaccharides. To study this, three different cabbage varieties, white cabbage (W), kale (K), and red kale (RK), were pretreated with 80% ethanol and then extracted with water at 50 degrees C and 100 degrees C for isolation of polysaccharide-containing fractions. The fractions were analyzed for monosaccharide composition, glycosidic linkages, Mw distribution, protein content, and phenolic compounds and then tested for complement-fixing activity. All fractions contained pectin type polysaccharides with linkages corresponding to homogalacturonan and hairy regions. Those extracted at 50 degrees C contained higher amounts of neutral side chains and were more active in the complement-fixation test than those extracted at 100 degrees C. The fractions can be ranged by decreasing activity: K-50 > RK-50 > W-50 approximately = K-100 > RK100 approximately = W-100. Studies on structure-activity relationships (SAR) employing multivariate statistical analysis strongly suggest that the magnitude of the measured activity is influenced by the content of certain side chains in the polymers. High activity correlates to large neutral side chains with high amounts of (1-->6)- and (1-->3,6)-linked Gal and low amounts of (1-->4)-linked GalA but not on molecular weight distribution of the polymers.

  9. Correlation of systemic lupus erythematosus disease activity with classical complement (CH50 function and related protein levels

    Directory of Open Access Journals (Sweden)

    Salesi M

    2008-09-01

    Full Text Available "nBackground: The components of the classical complement pathway play an important role in the pathogenesis of systemic lupus erythematosus (SLE and are reportedly useful biomarkers of disease activity. In this study, we evaluate disease activity, complement function (total hemolytic complement, CH50 and complement protein levels (C3, C4, C3d, C4d, SC5b-9, comparing the results of patients with active disease versus those with inactive disease."n"nMethods: This cross-sectional study included 78 hospitalized women with SLE, 24 of whom were in the active group, with SLE disease activity indexes (SLEDAI.2K of >6, and 54 in the inactive group, with SLEDAI.2K of ≤6. Serum CH50 was measured using a red blood cell hemolytic assay. C3 and C4 levels were determined by nephlometry and plasma levels of C3d, C4d, SC5b-9 by ELISA. The data were statistically analyzed using SPSS."n"nResults: The mean (±standard error C4d levels of the inactive group were significantly higher than those of the active group (23.39±1.1µg/ml and 16.9±1.6µg/ml, respectively; p=0.003. There was also a significant correlation between C3 and C4 levels (p=0.807. The mean values of the other proteins (C3, C4, CH50, SC5b-9, and C3d circulating immune complex concentrations were not significantly different between the inactive group vs. the active group: 89.35±6.8 vs. 85.54±7.6mg/dl, 18.33±2.3 vs. 20.45±2.4mg/dl, 149.03±4.3 vs. 157±4.3U, 1414.4±114.94 vs. 1471.1±216.9ng/ml, 9.43±0.96 vs. 13.31±3.16µgEq/ml, respectively (p>0.05."n"nConclusions: According to our results, C4d levels may be used as a biomarker of disease activity. The significant correlation between C3 and C4 may confirm the activity of the classical pathway in SLE patients."n"nKeywords: Systemic lupus erythematosus, CH50, C3, C4, C3d, C4d, SC5b-9, inactive, flare.

  10. A complement, not an alternative

    International Nuclear Information System (INIS)

    Schafhausen, F.

    1994-01-01

    Although self-imposed obligations of the economy have been used quite frequently in the past, this instrument is still regarded with a good deal of skepsis. Its advocates are nevertheless willed to stage its revival in the area of prophylactic climate protection. The article reports on first experiences with this wind of mechanism in the implentation of national strategies for climate protection in Denmark and the Netherlands. For the Netherlands it deals with the political concept, the procedure, the content of trade-internal agreements, sanctions, and an evaluation of what has been done. Denmark operates with energy and its and a CO 2 tax. (BWI) [de

  11. Plasma-derived human C1-esterase inhibitor does not prevent mechanical ventilation-induced pulmonary complement activation in a rat model of Streptococcus pneumoniae pneumonia

    NARCIS (Netherlands)

    de Beer, F. M.; Aslami, H.; Hoeksma, J.; van Mierlo, G.; Wouters, D.; Zeerleder, S.; Roelofs, J. J. T. H.; Juffermans, N. P.; Schultz, M. J.; Lagrand, W. K.

    2014-01-01

    Mechanical ventilation has the potential to cause lung injury, and the role of complement activation herein is uncertain. We hypothesized that inhibition of the complement cascade by administration of plasma-derived human C1-esterase inhibitor (C1-INH) prevents ventilation-induced pulmonary

  12. Crosstalk between complement and Toll-like receptor activation in relation to donor brain death and renal ischemia-reperfusion injury.

    Science.gov (United States)

    Damman, Jeffrey; Daha, Mohamed R; van Son, Willem J; Leuvenink, Henri G; Ploeg, Rutger J; Seelen, Marc A

    2011-04-01

    Two central pathways of innate immunity, complement and Toll-like receptors (TLRs), play an important role in the pathogenesis of renal injury inherent to kidney transplantation. Recent findings indicate close crosstalk between complement and TLR signaling pathways. It is suggested that mitogen activated protein kinases (MAPKs) might be the key molecules linking both the complement and TLR pathways together. Complement and TLRs are important mediators of renal ischemia-reperfusion injury (IRI). Besides IRI, complement C3 can also be upregulated and activated in the kidney before transplantation as a direct result of brain death (BD) in the donor. This local upregulation and activation of complement in the donor kidney has been proven to be detrimental for renal allograft outcome. Also TLR4 and several of its major ligands are upregulated by donor BD compared to living donors. Important and in line with the observations above, kidney transplant recipients have a benefit when receiving a kidney from a TLR4 Asp299Gly/Thr399Ile genotypic donor. The role of complement and TLRs and crosstalk between these two innate immune systems in relation to renal injury during donor BD and ischemia-reperfusion are focus of this review. Future strategies to target complement and TLR activation in kidney transplantation are considered. ©2011 The Authors Journal compilation©2011 The American Society of Transplantation and the American Society of Transplant Surgeons.

  13. Storage of the complement components C4, C3, and C 3-activator in the human liver as PAS-negative globular hyaline bodies.

    Science.gov (United States)

    Storch, W; Riedel, H; Trautmann, B; Justus, J; Hiemann, D

    1982-01-01

    Liver biopsies of a 58-year-old clinically healthy patient with a hepatomegaly and intracisternal PAS-negative globular hyaline bodies were immunofluorescent-optically examined for the content of the complement components C 1 q, C 4, C 9, C 1-inactivator, C 3-activator. Further examinations were performed for fibrinogen, IgG, IgA, IgM, IgD, IgE, L-chain (type chi and lambda), alpha 1-antitrypsin, alpha 1-fetoprotein, alpha 1- and alpha 2-glycoprotein, cholinesterase, ceruloplasmin, myoglobin, hemopexin, HBsAg and HBsAg. Th inclusion bodies reacted with antisera against the complement components C 4, C 3 and C 3-activator, as also identified by double immunofluorescence. Probably this is a disturbance of the protein metabolism of the liver cell with abnormal complement storage in the presence of normal total complement and normal complement components in the serum.

  14. Shark complement: an assessment.

    Science.gov (United States)

    Smith, S L

    1998-12-01

    The classical (CCP) and alternative (ACP) pathways of complement activation have been established for the nurse shark (Ginglymostoma cirratum). The isolation of a cDNA clone encoding a mannan-binding protein-associated serine protease (MASP)-1-like protein from the Japanese dogfish (Triakis scyllia) suggests the presence of a lectin pathway. The CCP consists of six functionally distinct components: C1n, C2n, C3n, C4n, C8n and C9n, and is activated by immune complexes in the presence of Ca++ and Mg++ ions. The ACP is antibody independent, requiring Mg++ ions and a heat-labile 90 kDa factor B-like protein for activity. Proteins considered homologues of C1q, C3 and C4 (C2n) of the mammalian complement system have been isolated from nurse shark serum. Shark C1q is composed of at least two chain types each showing 50% identity to human C1q chains A and B. Partial sequence of the globular domain of one of the chains shows it to be C1q-like rather than like mannan-binding protein. N-terminal amino acid sequences of the alpha and beta chain of shark C3 and C4 molecules show significant identity with corresponding human C3 and C4 chains. A sequence representing shark C4 gamma chain, shows little similarity to human C4 gamma chain. The terminal shark components C8n and C9n are functional analogues of mammalian C8 and C9. Anaphylatoxin activity has been demonstrated in activated shark serum, and porcine C5a desArg induces shark leucocyte chemotaxis. The deduced amino acid sequence of a partial C3 cDNA clone from the nurse shark shows 50%, 30% and 24% homology with the corresponding region of mammalian C3, C4 and alpha 2-macroglobulin. Deduced amino acid sequence data from partial Bf/C2 cDNA clones, two from the nurse shark and one from the Japanese dogfish, suggest that at least one species of elasmobranch has two distinct Bf/C2 genes.

  15. Dissociable effects of Sry and sex chromosome complement on activity, feeding and anxiety-related behaviours in mice.

    Science.gov (United States)

    Kopsida, Eleni; Lynn, Phoebe M; Humby, Trevor; Wilkinson, Lawrence S; Davies, William

    2013-01-01

    Whilst gonadal hormones can substantially influence sexual differentiation of the brain, recent findings have suggested that sex-linked genes may also directly influence neurodevelopment. Here we used the well-established murine 'four core genotype' (FCG) model on a gonadally-intact, outbred genetic background to characterise the contribution of Sry-dependent effects (i.e. those arising from the expression of the Y-linked Sry gene in the brain, or from hormonal sequelae of gonadal Sry expression) and direct effects of sex-linked genes other than Sry ('sex chromosome complement' effects) to sexually dimorphic mouse behavioural phenotypes. Over a 24 hour period, XX and XY gonadally female mice (lacking Sry) exhibited greater horizontal locomotor activity and reduced food consumption per unit bodyweight than XX and XY gonadally male mice (possessing Sry); in two behavioural tests (the elevated plus and zero mazes) XX and XY gonadally female mice showed evidence for increased anxiety-related behaviours relative to XX and XY gonadally male mice. Exploratory correlational analyses indicated that these Sry-dependent effects could not be simply explained by brain expression of the gene, nor by circulating testosterone levels. We also noted a sex chromosome complement effect on food (but not water) consumption whereby XY mice consumed more over a 24hr period than XX mice, and a sex chromosome complement effect in a third test of anxiety-related behaviour, the light-dark box. The present data suggest that: i) the male-specific factor Sry may influence activity and feeding behaviours in mice, and ii) dissociable feeding and anxiety-related murine phenotypes may be differentially modulated by Sry and by other sex-linked genes. Our results may have relevance for understanding the molecular underpinnings of sexually dimorphic behavioural phenotypes in healthy men and women, and in individuals with abnormal sex chromosome constitutions.

  16. Dissociable effects of Sry and sex chromosome complement on activity, feeding and anxiety-related behaviours in mice.

    Directory of Open Access Journals (Sweden)

    Eleni Kopsida

    Full Text Available Whilst gonadal hormones can substantially influence sexual differentiation of the brain, recent findings have suggested that sex-linked genes may also directly influence neurodevelopment. Here we used the well-established murine 'four core genotype' (FCG model on a gonadally-intact, outbred genetic background to characterise the contribution of Sry-dependent effects (i.e. those arising from the expression of the Y-linked Sry gene in the brain, or from hormonal sequelae of gonadal Sry expression and direct effects of sex-linked genes other than Sry ('sex chromosome complement' effects to sexually dimorphic mouse behavioural phenotypes. Over a 24 hour period, XX and XY gonadally female mice (lacking Sry exhibited greater horizontal locomotor activity and reduced food consumption per unit bodyweight than XX and XY gonadally male mice (possessing Sry; in two behavioural tests (the elevated plus and zero mazes XX and XY gonadally female mice showed evidence for increased anxiety-related behaviours relative to XX and XY gonadally male mice. Exploratory correlational analyses indicated that these Sry-dependent effects could not be simply explained by brain expression of the gene, nor by circulating testosterone levels. We also noted a sex chromosome complement effect on food (but not water consumption whereby XY mice consumed more over a 24hr period than XX mice, and a sex chromosome complement effect in a third test of anxiety-related behaviour, the light-dark box. The present data suggest that: i the male-specific factor Sry may influence activity and feeding behaviours in mice, and ii dissociable feeding and anxiety-related murine phenotypes may be differentially modulated by Sry and by other sex-linked genes. Our results may have relevance for understanding the molecular underpinnings of sexually dimorphic behavioural phenotypes in healthy men and women, and in individuals with abnormal sex chromosome constitutions.

  17. In Situ complement activation and T-cell immunity in leprosy spectrum: An immunohistological study on leprosy lesional skin.

    Directory of Open Access Journals (Sweden)

    Nawal Bahia El Idrissi

    Full Text Available Mycobacterium leprae (M. leprae infection causes nerve damage and the condition worsens often during and long after treatment. Clearance of bacterial antigens including lipoarabinomannan (LAM during and after treatment in leprosy patients is slow. We previously demonstrated that M. leprae LAM damages peripheral nerves by in situ generation of the membrane attack complex (MAC. Investigating the role of complement activation in skin lesions of leprosy patients might provide insight into the dynamics of in situ immune reactivity and the destructive pathology of M. leprae. In this study, we analyzed in skin lesions of leprosy patients, whether M. leprae antigen LAM deposition correlates with the deposition of complement activation products MAC and C3d on nerves and cells in the surrounding tissue. Skin biopsies of paucibacillary (n = 7, multibacillary leprosy patients (n = 7, and patients with erythema nodosum leprosum (ENL (n = 6 or reversal reaction (RR (n = 4 and controls (n = 5 were analyzed. The percentage of C3d, MAC and LAM deposition was significantly higher in the skin biopsies of multibacillary compared to paucibacillary patients (p = <0.05, p = <0.001 and p = <0.001 respectively, with a significant association between LAM and C3d or MAC in the skin biopsies of leprosy patients (r = 0.9578, p< 0.0001 and r = 0.8585, p<0.0001 respectively. In skin lesions of multibacillary patients, MAC deposition was found on axons and co-localizing with LAM. In skin lesions of paucibacillary patients, we found C3d positive T-cells in and surrounding granulomas, but hardly any MAC deposition. In addition, MAC immunoreactivity was increased in both ENL and RR skin lesions compared to non-reactional leprosy patients (p = <0.01 and p = <0.01 respectively. The present findings demonstrate that complement is deposited in skin lesions of leprosy patients, suggesting that inflammation driven by complement activation might contribute to nerve damage in the lesions

  18. Novel Evasion Mechanisms of the Classical Complement Pathway.

    Science.gov (United States)

    Garcia, Brandon L; Zwarthoff, Seline A; Rooijakkers, Suzan H M; Geisbrecht, Brian V

    2016-09-15

    Complement is a network of soluble and cell surface-associated proteins that gives rise to a self-amplifying, yet tightly regulated system with fundamental roles in immune surveillance and clearance. Complement becomes activated on the surface of nonself cells by one of three initiating mechanisms known as the classical, lectin, and alternative pathways. Evasion of complement function is a hallmark of invasive pathogens and hematophagous organisms. Although many complement-inhibition strategies hinge on hijacking activities of endogenous complement regulatory proteins, an increasing number of uniquely evolved evasion molecules have been discovered over the past decade. In this review, we focus on several recent investigations that revealed mechanistically distinct inhibitors of the classical pathway. Because the classical pathway is an important and specific mediator of various autoimmune and inflammatory disorders, in-depth knowledge of novel evasion mechanisms could direct future development of therapeutic anti-inflammatory molecules. Copyright © 2016 by The American Association of Immunologists, Inc.

  19. BF*F allotype of the alternative pathway of complement: A marker of protection against the development of antiphospholipid antibodies in patients with systemic lupus erythematosus.

    Science.gov (United States)

    Picceli, V F; Skare, T L; Nisihara, R M; Nass, F R; Messias-Reason, I T; Utiyama, S R R

    2016-04-01

    B factor (BF) from the alternative complement pathway seems to participate in the pathophysiology of systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). To study the allotypic variability of BF in SLE and their associations with clinical and autoantibodies profile. BF allotypes were determined by high-voltage agarose gel electrophoresis, under constant cooling, followed by immunofixation with anti-human BF antibody, in 188 SLE patients and 103 controls. Clinical and serological data were obtained from medical examination and records. No significant differences of BF variants between patients and controls were found, neither in relation to epidemiologic or clinical manifestations. Associations of phenotype BF SS07 and allotype BF*S07 were found with anticardiolipin IgM (aCl-IgM) antibodies (p = 0.014 and p = 0.009 respectively), but not with aCl-IgG, lupus anticoagulant (LA), anti β2GPI or clinical APS. A significant decrease in BF*F allotype (p = 0.043) and BF SF phenotype (p = 0.018) was detected in patients with anti-phospholipid antibodies as a whole (aCl-IgG, aCl-IgM, LA and anti β2GPI). There is a link between phenotype BF SS07 and allotype BF*S07 with aCl-IgM in SLE patients; BF*F allotype could be considered a marker of protection against the development of antiphospholipid antibodies in these patients. © The Author(s) 2015.

  20. Complement activation-related pseudoallergy in dogs following intravenous administration of a liposomal formulation of meglumine antimoniate

    Directory of Open Access Journals (Sweden)

    Raul R. Ribeiro

    2013-08-01

    Full Text Available The increasing use of nanotechnologies in advanced therapies has allowed the observation of specific adverse reactions related to nanostructures. The toxicity of a novel liposome formulation of meglumine antimoniate in dogs with visceral leishmaniasis after single dose has been investigated. Groups of 12 animals received by the intravenous route a single dose of liposomal meglumine antimoniate (group I [GI], 6.5 mg Sb/kg, empty liposomes (GII or isotonic saline (GIII. Evaluation of hematological and biochemical parameters showed no significant changes 4 days after administration. No undesired effects were registered in the GIII. However, adverse reactions were observed in 67.7% of dogs from both groups that received liposomal formulations. The side effects began moments after bolus administration and disappeared during the first 15 minutes after treatment. Prostation, sialorrhea and defecation were the most frequent clinical signs, registered in 33.3% and 41.6 % of animals from the groups GI and GII, respectively. Tachypnea, mydriasis, miosis, vomiting and cyanosis were also registered in both groups. The adverse reactions observed in this study were attributed to the activation of the complement system by lipid vesicles in a phenomenon known as Complement Activation-Related Pseudoallergy (CARPA. The influence of the physical-chemical characteristics of liposomal formulation in the triggering of CARPA is discussed.

  1. Infusion Reactions Associated with the Medical Application of Monoclonal Antibodies: The Role of Complement Activation and Possibility of Inhibition by Factor H

    OpenAIRE

    Tamás Fülöp; Tamás Mészáros; Gergely Tibor Kozma; János Szebeni; Mihály Józsi

    2018-01-01

    Human application of monoclonal antibodies (mAbs), enzymes, as well as contrast media and many other particulate drugs and agents referred to as “nanomedicines”, can initiate pseudoallergic hypersensitivity reactions, also known as infusion reactions. These may in part be mediated by the activation of the complement system, a major humoral defense system of innate immunity. In this review, we provide a brief outline of complement activation-related pseudoallergy (CARPA) in general, and then f...

  2. Tsetse GmmSRPN10 has anti-complement activity and is important for successful establishment of trypanosome infections in the fly midgut.

    Directory of Open Access Journals (Sweden)

    Cher-Pheng Ooi

    2015-01-01

    Full Text Available The complement cascade in mammalian blood can damage the alimentary tract of haematophagous arthropods. As such, these animals have evolved their own repertoire of complement-inactivating factors, which are inadvertently exploited by blood-borne pathogens to escape complement lysis. Unlike the bloodstream stages, the procyclic (insect stage of Trypanosoma brucei is highly susceptible to complement killing, which is puzzling considering that a tsetse takes a bloodmeal every 2-4 days. In this study, we identified four tsetse (Glossina morsitans morsitans serine protease inhibitors (serpins from a midgut expressed sequence tag (EST library (GmmSRPN3, GmmSRPN5, GmmSRPN9 and GmmSRPN10 and investigated their role in modulating the establishment of a T. brucei infection in the midgut. Although not having evolved in a common blood-feeding ancestor, all four serpins have an active site sharing remarkable homology with the human complement C1-inhibitor serpin, SerpinG1. RNAi knockdown of individual GmmSRPN9 and GmmSRPN10 genes resulted in a significant decreased rate of infection by procyclic form T. brucei. Furthermore, recombinant GmmSRPN10 was both able to inhibit the activity of human complement-cascade serine proteases, C1s and Factor D, and to protect the in vitro killing of procyclic trypanosomes when incubated with complement-activated human serum. Thus, the secretion of serpins, which may be part of a bloodmeal complement inactivation system in tsetse, is used by procyclic trypanosomes to evade an influx of fresh trypanolytic complement with each bloodmeal. This highlights another facet of the complicated relationship between T. brucei and its tsetse vector, where the parasite takes advantage of tsetse physiology to further its chances of propagation and transmission.

  3. Tsetse GmmSRPN10 has anti-complement activity and is important for successful establishment of trypanosome infections in the fly midgut.

    Science.gov (United States)

    Ooi, Cher-Pheng; Haines, Lee R; Southern, Daniel M; Lehane, Michael J; Acosta-Serrano, Alvaro

    2015-01-01

    The complement cascade in mammalian blood can damage the alimentary tract of haematophagous arthropods. As such, these animals have evolved their own repertoire of complement-inactivating factors, which are inadvertently exploited by blood-borne pathogens to escape complement lysis. Unlike the bloodstream stages, the procyclic (insect) stage of Trypanosoma brucei is highly susceptible to complement killing, which is puzzling considering that a tsetse takes a bloodmeal every 2-4 days. In this study, we identified four tsetse (Glossina morsitans morsitans) serine protease inhibitors (serpins) from a midgut expressed sequence tag (EST) library (GmmSRPN3, GmmSRPN5, GmmSRPN9 and GmmSRPN10) and investigated their role in modulating the establishment of a T. brucei infection in the midgut. Although not having evolved in a common blood-feeding ancestor, all four serpins have an active site sharing remarkable homology with the human complement C1-inhibitor serpin, SerpinG1. RNAi knockdown of individual GmmSRPN9 and GmmSRPN10 genes resulted in a significant decreased rate of infection by procyclic form T. brucei. Furthermore, recombinant GmmSRPN10 was both able to inhibit the activity of human complement-cascade serine proteases, C1s and Factor D, and to protect the in vitro killing of procyclic trypanosomes when incubated with complement-activated human serum. Thus, the secretion of serpins, which may be part of a bloodmeal complement inactivation system in tsetse, is used by procyclic trypanosomes to evade an influx of fresh trypanolytic complement with each bloodmeal. This highlights another facet of the complicated relationship between T. brucei and its tsetse vector, where the parasite takes advantage of tsetse physiology to further its chances of propagation and transmission.

  4. Ameloginins promote an alternatively activated macrophage phenotype in vitro

    DEFF Research Database (Denmark)

    Almqvist, S; Werthen, M; Lyngstadas, SP

    2011-01-01

    aggregates were visualised by transmission electron microscopy. The amelogenin treatment of macrophages increased several pro- and anti-inflammatory cytokines, including alternative macrophage activation marker AMAC-1 (p

  5. Complement binding to erythrocytes is associated with macrophage activation and reduced haemoglobin in Plasmodium falciparum malaria

    DEFF Research Database (Denmark)

    Goka, B Q; Kwarko, H; Kurtzhals, J A

    2001-01-01

    parameters were significantly higher in DAT-positive than in DAT-negative patients (P macrophage activation. Plasma levels of haptoglobin, interleukin-10 and tumour necrosis factor-alpha did not vary between the groups...

  6. Specific alterations in complement protein activity of little brown myotis (Myotis lucifugus hibernating in white-nose syndrome affected sites.

    Directory of Open Access Journals (Sweden)

    Marianne S Moore

    Full Text Available White-nose syndrome (WNS is the most devastating condition ever reported for hibernating bats, causing widespread mortality in the northeastern United States. The syndrome is characterized by cutaneous lesions caused by a recently identified psychrophilic and keratinophylic fungus (Geomyces destructans, depleted fat reserves, atypical behavior, and damage to wings; however, the proximate cause of mortality is still uncertain. To assess relative levels of immunocompetence in bats hibernating in WNS-affected sites compared with levels in unaffected bats, we describe blood plasma complement protein activity in hibernating little brown myotis (Myotis lucifugus based on microbicidal competence assays using Escherichia coli, Staphylococcus aureus and Candida albicans. Blood plasma from bats collected during mid-hibernation at WNS-affected sites had higher bactericidal ability against E. coli and S. aureus, but lower fungicidal ability against C. albicans when compared with blood plasma from bats collected at unaffected sites. Within affected sites during mid-hibernation, we observed no difference in microbicidal ability between bats displaying obvious fungal infections compared to those without. Bactericidal ability against E. coli decreased significantly as hibernation progressed in bats collected from an affected site. Bactericidal ability against E. coli and fungicidal ability against C. albicans were positively correlated with body mass index (BMI during late hibernation. We also compared complement activity against the three microbes within individuals and found that the ability of blood plasma from hibernating M. lucifugus to lyse microbial cells differed as follows: E. coli>S. aureus>C. albicans. Overall, bats affected by WNS experience both relatively elevated and reduced innate immune responses depending on the microbe tested, although the cause of observed immunological changes remains unknown. Additionally, considerable trade-offs may exist

  7. Specific alterations in complement protein activity of little brown myotis (Myotis lucifugus) hibernating in white-nose syndrome affected sites.

    Science.gov (United States)

    Moore, Marianne S; Reichard, Jonathan D; Murtha, Timothy D; Zahedi, Bita; Fallier, Renee M; Kunz, Thomas H

    2011-01-01

    White-nose syndrome (WNS) is the most devastating condition ever reported for hibernating bats, causing widespread mortality in the northeastern United States. The syndrome is characterized by cutaneous lesions caused by a recently identified psychrophilic and keratinophylic fungus (Geomyces destructans), depleted fat reserves, atypical behavior, and damage to wings; however, the proximate cause of mortality is still uncertain. To assess relative levels of immunocompetence in bats hibernating in WNS-affected sites compared with levels in unaffected bats, we describe blood plasma complement protein activity in hibernating little brown myotis (Myotis lucifugus) based on microbicidal competence assays using Escherichia coli, Staphylococcus aureus and Candida albicans. Blood plasma from bats collected during mid-hibernation at WNS-affected sites had higher bactericidal ability against E. coli and S. aureus, but lower fungicidal ability against C. albicans when compared with blood plasma from bats collected at unaffected sites. Within affected sites during mid-hibernation, we observed no difference in microbicidal ability between bats displaying obvious fungal infections compared to those without. Bactericidal ability against E. coli decreased significantly as hibernation progressed in bats collected from an affected site. Bactericidal ability against E. coli and fungicidal ability against C. albicans were positively correlated with body mass index (BMI) during late hibernation. We also compared complement activity against the three microbes within individuals and found that the ability of blood plasma from hibernating M. lucifugus to lyse microbial cells differed as follows: E. coli>S. aureus>C. albicans. Overall, bats affected by WNS experience both relatively elevated and reduced innate immune responses depending on the microbe tested, although the cause of observed immunological changes remains unknown. Additionally, considerable trade-offs may exist between energy

  8. CFH Y402H polymorphism and the complement activation product C5a: effects on NF-κB activation and inflammasome gene regulation.

    Science.gov (United States)

    Cao, Sijia; Wang, Jay Ching Chieh; Gao, Jiangyuan; Wong, Matthew; To, Elliott; White, Valerie A; Cui, Jing Z; Matsubara, Joanne A

    2016-05-01

    The Y402H polymorphism in the complement factor H (CFH) gene is an important risk factor for age-related macular degeneration (AMD). Complement activation products and proinflammatory cytokines are associated with this polymorphism at the systemic level, but less is known of the associations in the outer retina of the genotyped eye. Here we investigate complement activation products and their role in nuclear factor (NF)-κB activation and gene expression of the NLRP3 inflammasome pathway. Postmortem donor eyes were genotyped for the CFH Y402H polymorphism and assessed for complement C3a, C5a, interleukin (IL)-18 and tumour necrosis factor (TNF)-α. ARPE19 cells were stimulated basolaterally with C5a or TNF-α in polarised cultures. NF-κB activation was assessed with a reporter cell line. Gene expression of inflammasome-related (NLRP3, caspase-1, IL-1β and IL-18) and classic inflammatory (IL-6 and IL-8) genes was studied. The distribution of inflammasome products, IL-1β and IL-18, was studied in postmortem donor eyes with AMD pathologies. Eyes with the homozygous at-risk variant demonstrated higher levels of C5a, IL-18 and TNF-α in Bruch's membrane and choroid. C5a promoted NF-κB activation and upregulation of IL-18 in polarised ARPE19. TNF-α promoted NF-κB activation and gene expression of caspase-1, IL-1β, IL-18, IL-6 and IL-8, but downregulated NLRP3. In eyes with geographic atrophy, strong immunoreactivity was observed for inflammasome products IL-1β and IL-18 compared with age-matched controls. The at-risk polymorphism of the CFH Y402H may contribute to AMD disease process through increased complement and NF-κB activation, and the upregulation of IL-18, a product of inflammasome activation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  9. The influence of gamma radiation upon the biological activity of the third serum complement component (C3)

    International Nuclear Information System (INIS)

    Steuhl, K.P.; Dierich, M.P.; Mainz Univ.

    1981-01-01

    For investigation of interaction between C3 and C3-binding cells the third complement component is to be labelled with radiotracer. After labelling C3 with high specific activity (0,2 μCi 125 l/μg C3) binding of C3 to Raji-cells was increased up to the twentyfold nine days after labelling. This effect was not to be reproduced with external gamma radiation using doses of 10, 200 and 1000 rad. The rosette inhibition test could demonstrate that with radiation doses of 200 and 1000 rad the radiated C3 lost its ability of specific binding to C3 receptors in Raji-cells. This functional alteration corresponded to amino acid analysis with relative increase of asparagine, glutamic acid and proline and relative decrease of cystine and phenylalanine in the C3 molecule. (orig.) [de

  10. Amblyomma americanum tick calreticulin binds C1q but does not inhibit activation of the classical complement cascade.

    Science.gov (United States)

    Kim, Tae Kwon; Ibelli, Adriana Mércia Guaratini; Mulenga, Albert

    2015-02-01

    In this study we characterized Amblyomma americanum (Aam) tick calreticulin (CRT) homolog in tick feeding physiology. In nature, different tick species can be found feeding on the same animal host. This suggests that different tick species found feeding on the same host can modulate the same host anti-tick defense pathways to successfully feed. From this perspective it's plausible that different tick species can utilize universally conserved proteins such as CRT to regulate and facilitate feeding. CRT is a multi-functional protein found in most taxa that is injected into the vertebrate host during tick feeding. Apart from it's current use as a biomarker for human tick bites, role(s) of this protein in tick feeding physiology have not been elucidated. Here we show that annotated functional CRT amino acid motifs are well conserved in tick CRT. However our data show that despite high amino acid identity levels to functionally characterized CRT homologs in other organisms, AamCRT is apparently functionally different. Pichia pastoris expressed recombinant (r) AamCRT bound C1q, the first component of the classical complement system, but it did not inhibit activation of this pathway. This contrast with reports of other parasite CRT that inhibited activation of the classical complement pathway through sequestration of C1q. Furthermore rAamCRT did not bind factor Xa in contrast to reports of parasite CRT binding factor Xa, an important protease in the blood clotting system. Consistent with this observation, rAamCRT did not affect plasma clotting or platelet aggregation. We discuss our findings in the context of tick feeding physiology.

  11. Suppression of complement regulatory protein C1 inhibitor in vascular endothelial activation by inhibiting vascular cell adhesion molecule-1 action

    International Nuclear Information System (INIS)

    Zhang, Haimou; Qin, Gangjian; Liang, Gang; Li, Jinan; Chiu, Isaac; Barrington, Robert A.; Liu, Dongxu

    2007-01-01

    Increased expression of adhesion molecules by activated endothelium is a critical feature of vascular inflammation associated with the several diseases such as endotoxin shock and sepsis/septic shock. Our data demonstrated complement regulatory protein C1 inhibitor (C1INH) prevents endothelial cell injury. We hypothesized that C1INH has the ability of an anti-endothelial activation associated with suppression of expression of adhesion molecule(s). C1INH blocked leukocyte adhesion to endothelial cell monolayer in both static assay and flow conditions. In inflammatory condition, C1INH reduced vascular cell adhesion molecule (VCAM-1) expression associated with its cytoplasmic mRNA destabilization and nuclear transcription level. Studies exploring the underlying mechanism of C1INH-mediated suppression in VCAM-1 expression were related to reduction of NF-κB activation and nuclear translocation in an IκBα-dependent manner. The inhibitory effects were associated with reduction of inhibitor IκB kinase activity and stabilization of the NF-κB inhibitor IκB. These findings indicate a novel role for C1INH in inhibition of vascular endothelial activation. These observations could provide the basis for new therapeutic application of C1INH to target inflammatory processes in different pathologic situations

  12. Control of the classical and the MBL pathway of complement activation

    DEFF Research Database (Denmark)

    Petersen, Steen Vang; Thiel, S; Jensen, L

    2000-01-01

    and the influence of high ionic strength on the complexes indicate that the activation and control of the MBL pathway differ from that of the classical pathway. MBL deficiency is linked to various clinical manifestations such as recurrent infections, severe diarrhoea, and recurrent miscarriage. On the other hand...... incubation at 37 degrees C in physiological buffer, the associated inhibitors as well as MASP-1, MASP-2, and MAp19 dissociated from MBL, whereas only little dissociation of the complex occurred in buffer with high ionic strength (1 M NaCl). The difference in sensitivity to various inhibitors...

  13. Calcineurin inhibitor-induced complement system activation via ERK1/2 signalling is inhibited by SOCS-3 in human renal tubule cells.

    Science.gov (United States)

    Loeschenberger, Beatrix; Niess, Lea; Würzner, Reinhard; Schwelberger, Hubert; Eder, Iris E; Puhr, Martin; Guenther, Julia; Troppmair, Jakob; Rudnicki, Michael; Neuwirt, Hannes

    2018-02-01

    One factor that significantly contributes to renal allograft loss is chronic calcineurin inhibitor (CNI) nephrotoxicity (CIN). Among other factors, the complement (C-) system has been proposed to be involved CIN development. Hence, we investigated the impact of CNIs on intracellular signalling and the effects on the C-system in human renal tubule cells. In a qPCR array, CNI treatment upregulated C-factors and downregulated SOCS-3 and the complement inhibitors CD46 and CD55. Additionally, ERK1/-2 was required for these regulations. Following knock-down and overexpression of SOCS-3, we found that SOCS-3 inhibits ERK1/-2 signalling. Finally, we assessed terminal complement complex formation, cell viability and apoptosis. Terminal complement complex formation was induced by CNIs. Cell viability was significantly decreased, whereas apoptosis was increased. Both effects were reversed under complement component-depleted conditions. In vivo, increased ERK1/-2 phosphorylation and SOCS-3 downregulation were observed at the time of transplantation in renal allograft patients who developed a progressive decline of renal function in the follow-up compared to stable patients. The progressive cohort also had lower total C3 levels, suggesting higher complement activity at baseline. In conclusion, our data suggest that SOCS-3 inhibits CNI-induced ERK1/-2 signalling, thereby blunting the negative control of C-system activation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Complement-mediated bactericidal activity of anti-factor H binding protein monoclonal antibodies against the meningococcus relies upon blocking factor H binding.

    Science.gov (United States)

    Giuntini, Serena; Reason, Donald C; Granoff, Dan M

    2011-09-01

    Binding of the complement-downregulating protein factor H (fH) to the surface of the meningococcus is important for survival of the organism in human serum. The meningococcal vaccine candidate factor H binding protein (fHbp) is an important ligand for human fH. While some fHbp-specific monoclonal antibodies (MAbs) block binding of fH to fHbp, the stoichiometry of blocking in the presence of high serum concentrations of fH and its effect on complement-mediated bactericidal activity are unknown. To investigate this question, we constructed chimeric antibodies in which the human IgG1 constant region was paired with three murine fHbp-specific binding domains designated JAR 3, JAR 5, and MAb502. By surface plasmon resonance, the association rates for binding of all three MAbs to immobilized fHbp were >50-fold higher than that for binding of fH to fHbp, and the MAb dissociation rates were >500-fold lower than that for fH. While all three MAbs elicited similar C1q-dependent C4b deposition on live bacteria (classical complement pathway), only those antibodies that inhibited binding of fH to fHbp (JAR 3 and JAR 5) had bactericidal activity with human complement. MAb502, which did not inhibit fH binding, had complement-mediated bactericidal activity only when tested with fH-depleted human complement. When an IgG1 anti-fHbp MAb binds to sparsely exposed fHbp on the bacterial surface, there appears to be insufficient complement activation for bacteriolysis unless fH binding also is inhibited. The ability of fHbp vaccines to elicit protective antibodies, therefore, is likely to be enhanced if the antibody repertoire is of high avidity and includes fH-blocking activity.

  15. Activity Therapy: An Alternative Therapy for Adolescents.

    Science.gov (United States)

    Kottman, Terry T.; And Others

    1987-01-01

    Discusses the benefits of activity therapy for preteens and adolescents, where the client is engaged in nonverbal modes of relationship--games, free play, movement, drama, music, art or other activities, as the chief therapeutic media in which conflicts are resolved and intellectual and emotional energies freed. Reviews the literature, describes…

  16. Nanomedicine and the complement paradigm.

    Science.gov (United States)

    Moghimi, S Moein; Farhangrazi, Z Shadi

    2013-05-01

    The role of complement in idiosyncratic reactions to nanopharmaceutical infusion is receiving increasing attention. We discuss this in relation to nanopharmaceutical development and the possible use of complement inhibitors to prevent related adverse reactions. We further call on initiation of genetic association studies to unravel the genetic basis of nanomedicine infusion-related adverse responses, since most of the polymorphic genes in the genome belong to the immune system. In this paper, idiosyncratic reactions based on complement activation are discussed in the context of newly available complement inhibitors. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Disease-linked mutations in factor H reveal pivotal role of cofactor activity in self-surface-selective regulation of complement activation.

    Science.gov (United States)

    Kerr, Heather; Wong, Edwin; Makou, Elisavet; Yang, Yi; Marchbank, Kevin; Kavanagh, David; Richards, Anna; Herbert, Andrew P; Barlow, Paul N

    2017-08-11

    Spontaneous activation enables the complement system to respond very rapidly to diverse threats. This activation is efficiently suppressed by complement factor H (CFH) on self-surfaces but not on foreign surfaces. The surface selectivity of CFH, a soluble protein containing 20 complement-control protein modules (CCPs 1-20), may be compromised by disease-linked mutations. However, which of the several functions of CFH drives this self-surface selectivity remains unknown. To address this, we expressed human CFH mutants in Pichia pastoris We found that recombinant I62-CFH (protective against age-related macular degeneration) and V62-CFH functioned equivalently, matching or outperforming plasma-derived CFH, whereas R53H-CFH, linked to atypical hemolytic uremic syndrome (aHUS), was defective in C3bBb decay-accelerating activity (DAA) and factor I cofactor activity (CA). The aHUS-linked CCP 19 mutant D1119G-CFH had virtually no CA on (self-like) sheep erythrocytes ( E S ) but retained DAA. The aHUS-linked CCP 20 mutant S1191L/V1197A-CFH (LA-CFH) had dramatically reduced CA on E S but was less compromised in DAA. D1119G-CFH and LA-CFH both performed poorly at preventing complement-mediated hemolysis of E S PspCN, a CFH-binding Streptococcus pneumoniae protein domain, binds CFH tightly and increases accessibility of CCPs 19 and 20. PspCN did not improve the DAA of any CFH variant on E S Conversely, PspCN boosted the CA, on E S , of I62-CFH, R53H-CFH, and LA-CFH and also enhanced hemolysis protection by I62-CFH and LA-CFH. We conclude that CCPs 19 and 20 are critical for efficient CA on self-surfaces but less important for DAA. Exposing CCPs 19 and 20 with PspCN and thus enhancing CA on self-surfaces may reverse deficiencies of some CFH variants. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Cardiac Sirt1 mediates the cardioprotective effect of caloric restriction by suppressing local complement system activation after ischemia-reperfusion.

    Science.gov (United States)

    Yamamoto, Tsunehisa; Tamaki, Kayoko; Shirakawa, Kohsuke; Ito, Kentaro; Yan, Xiaoxiang; Katsumata, Yoshinori; Anzai, Atsushi; Matsuhashi, Tomohiro; Endo, Jin; Inaba, Takaaki; Tsubota, Kazuo; Sano, Motoaki; Fukuda, Keiichi; Shinmura, Ken

    2016-04-15

    Caloric restriction (CR) confers cardioprotection against ischemia-reperfusion (I/R) injury. We previously found the essential roles of endothelial nitric oxide synthase in the development of CR-induced cardioprotection and Sirt1 activation during CR (Shinmura K, Tamaki K, Ito K, Yan X, Yamamoto T, Katsumata Y, Matsuhashi T, Sano M, Fukuda K, Suematsu M, Ishii I. Indispensable role of endothelial nitric oxide synthase in caloric restriction-induced cardioprotection against ischemia-reperfusion injury.Am J Physiol Heart Circ Physiol 308: H894-H903, 2015). However, the exact mechanism by which Sirt1 in cardiomyocytes mediates the cardioprotective effect of CR remains undetermined. We subjected cardiomyocyte-specific Sirt1 knockout (CM-Sirt1(-/-)) mice and the corresponding control mice to either 3-mo ad libitum feeding or CR (-40%). Isolated perfused hearts were subjected to 25-min global ischemia, followed by 60-min reperfusion. The recovery of left ventricle function after I/R was improved, and total lactate dehydrogenase release into the perfusate during reperfusion was attenuated in the control mice treated with CR, but a similar cardioprotective effect of CR was not observed in the CM-Sirt1(-/-)mice. The expression levels of cardiac complement component 3 (C3) at baseline and the accumulation of C3 and its fragments in the ischemia-reperfused myocardium were attenuated by CR in the control mice, but not in the CM-Sirt1(-/-)mice. Resveratrol treatment also attenuated the expression levels of C3 protein in cultured neonatal rat ventricular cardiomyocytes. Moreover, the degree of myocardial I/R injury in conventional C3 knockout (C3(-/-)) mice treated with CR was similar to that in the ad libitum-fed C3(-/-)mice, although the expression levels of Sirt1 were enhanced by CR. These results demonstrate that cardiac Sirt1 plays an essential role in CR-induced cardioprotection against I/R injury by suppressing cardiac C3 expression. This is the first report suggesting

  19. Xeroderma pigmentosum complementation group C cells remove pyrimidine dimers selectively from the transcribed strand of active genes

    International Nuclear Information System (INIS)

    Venema, J.; van Hoffen, A.; Karcagi, V.; Natarajan, A.T.; van Zeeland, A.A.; Mullenders, L.H.

    1991-01-01

    The authors have measured the removal of UV-induced pyrimidine dimers from DNA fragments of the adenosine deaminase (ADA) and dihydrofolate reductase (DHFR) genes in primary normal human and xeroderma pigmentosum complementation group C (XP-C) cells. Using strand-specific probes, we show that in normal cells, preferential repair of the 5' part of the ADA gene is due to the rapid and efficient repair of the transcribed strand. Within 8 h after irradiation with UV at 10 J m-2, 70% of the pyrimidine dimers in this strand are removed. The nontranscribed strand is repaired at a much slower rate, with 30% dimers removed after 8 h. Repair of the transcribed strand in XP-C cells occurs at a rate indistinguishable from that in normal cells, but the nontranscribed strand is not repaired significantly in these cells. Similar results were obtained for the DHFR gene. In the 3' part of the ADA gene, however, both normal and XP-C cells perform fast and efficient repair of either strand, which is likely to be caused by the presence of transcription units on both strands. The factor defective in XP-C cells is apparently involved in the processing of DNA damage in inactive parts of the genome, including nontranscribed strands of active genes. These findings have important implications for the understanding of the mechanism of UV-induced excision repair and mutagenesis in mammalian cells

  20. Complement-Mediated Enhancement of Monocyte Adhesion to Endothelial Cells by HLA Antibodies, and Blockade by a Specific Inhibitor of the Classical Complement Cascade, TNT003

    Science.gov (United States)

    Valenzuela, Nicole M.; Thomas, Kimberly A.; Mulder, Arend; Parry, Graham C.; Panicker, Sandip; Reed, Elaine F.

    2017-01-01

    Background Antibody-mediated rejection (AMR) of most solid organs is characterized by evidence of complement activation and/or intragraft macrophages (C4d + and CD68+ biopsies). We previously demonstrated that crosslinking of HLA I by antibodies triggered endothelial activation and monocyte adhesion. We hypothesized that activation of the classical complement pathway at the endothelial cell surface by HLA antibodies would enhance monocyte adhesion through soluble split product generation, in parallel with direct endothelial activation downstream of HLA signaling. Methods Primary human aortic endothelial cells (HAEC) were stimulated with HLA class I antibodies in the presence of intact human serum complement. C3a and C5a generation, endothelial P-selectin expression, and adhesion of human primary and immortalized monocytes (Mono Mac 6) were measured. Alternatively, HAEC or monocytes were directly stimulated with purified C3a or C5a. Classical complement activation was inhibited by pretreatment of complement with an anti-C1s antibody (TNT003). Results Treatment of HAEC with HLA antibody and human complement increased the formation of C3a and C5a. Monocyte recruitment by human HLA antibodies was enhanced in the presence of intact human serum complement or purified C3a or C5a. Specific inhibition of the classical complement pathway using TNT003 or C1q-depleted serum significantly reduced adhesion of monocytes in the presence of human complement. Conclusions Despite persistent endothelial viability in the presence of HLA antibodies and complement, upstream complement anaphylatoxin production exacerbates endothelial exocytosis and leukocyte recruitment. Upstream inhibition of classical complement may be therapeutic to dampen mononuclear cell recruitment and endothelial activation characteristic of microvascular inflammation during AMR. PMID:28640789

  1. Activation of Human Complement System by Dextran-Coated Iron Oxide Nanoparticles Is Not Affected by Dextran/Fe Ratio, Hydroxyl Modifications, and Crosslinking

    DEFF Research Database (Denmark)

    Wang, Guankui; Chen, Fangfang; Banda, Nirmal K

    2016-01-01

    While having tremendous potential as therapeutic and imaging tools, the clinical use of engineered nanoparticles has been associated with serious safety concerns. Activation of the complement cascade and the release of proinflammatory factors C3a and C5a may contribute to infusion-related reactio...

  2. Potential of Murine IgG1 and Human IgG4 to Inhibit the Classical Complement and Fcγ Receptor Activation Pathways

    Directory of Open Access Journals (Sweden)

    Gina-Maria Lilienthal

    2018-05-01

    Full Text Available IgG antibodies (Abs mediate their effector functions through the interaction with Fcγ receptors (FcγRs and the complement factors. The main IgG-mediated complement activation pathway is induced through the binding of complement C1q to IgG Abs. This interaction is dependent on antigen-dependent hexamer formation of human IgG1 and IgG3 to increase the affinity for the six-headed C1q molecule. By contrast, human IgG4 fails to bind to C1q. Instead, it has been suggested that human IgG4 can block IgG1 and IgG3 hexamerization required for their binding to C1q and activating the complement. Here, we show that murine IgG1, which functionally resembles human IgG4 by not interacting with C1q, inhibits the binding of IgG2a, IgG2b, and IgG3 to C1q in vitro, and suppresses IgG2a-mediated complement activation in a hemolytic assay in an antigen-dependent and IgG subclass-specific manner. From this perspective, we discuss the potential of murine IgG1 and human IgG4 to block the complement activation as well as suppressive effects of sialylated IgG subclass Abs on FcγR-mediated immune cell activation. Accumulating evidence suggests that both mechanisms seem to be responsible for preventing uncontrolled IgG (autoAb-induced inflammation in mice and humans. Distinct IgG subclass distributions and functionally opposite IgG Fc glycosylation patterns might explain different outcomes of IgG-mediated immune responses and provide new therapeutic options through the induction, enrichment, or application of antigen-specific sialylated human IgG4 to prevent complement and FcγR activation as well.

  3. Complement in patients receiving maintenance hemodialysis: functional screening and quantitative analysis

    Directory of Open Access Journals (Sweden)

    Horikoshi Satoshi

    2010-12-01

    Full Text Available Abstract Background The complement system is vital for innate immunity and is implicated in the pathogenesis of inflammatory diseases and the mechanism of host defense. Complement deficiencies occasionally cause life-threatening diseases. In hemodialysis (HD patients, profiles on complement functional activity and deficiency are still obscure. The objectives of the present study were to measure the functional complement activities of the classical pathway (CP, lectin pathway (LP and alternative pathway (AP using a novel method and consequently to elucidate the rates of deficiencies among HD patients. Methods In the present study, 244 HD patients at one dialysis center and 204 healthy controls were enrolled. Functional complement activities were measured simultaneously using the Wielisa®-kit. The combination of the results of these three pathway activities allows us to speculate which candidate complement is deficient; subsequently, the deficient complement was determined. Results All three functional complement activities were significantly higher in the HD patients than in the control group (P ®-kit, 16 sera (8.8% with mannose-binding lectin (MBL deficiency, 1 serum (0.4% with C4 deficiency, 1 serum (0.4% with C9 deficiency, and 1 serum (0.4% with B deficiency were observed in the HD group, and 18 sera (8.8% with MBL deficiency and 1 serum (0.5% with B deficiency were observed in the control group. There were no significant differences in the 5-year mortality rate between each complement-deficient group and the complement-sufficient group among the HD patients. Conclusion This is the first report that profiles complement deficiencies by simultaneous measurement of functional activities of the three complement pathways in HD patients. Hemodialysis patients frequently suffer from infections or malignancies, but functional complement deficiencies do not confer additional risk of mortality.

  4. Visceral perfusion abnormalities following complement activation. Clues to the mediators of organ ischemia in trauma and sepsis. First place winner: Conrad Jobst Award.

    Science.gov (United States)

    Schirmer, W J; Schirmer, J M; Naff, G B; Fry, D E

    1988-12-01

    Complement, activated during infection and injury, has been implicated as a mediator of microvascular injury and obstruction. This study examines how two potent activators of complement, zymosan, and cobra venom factor (CVF), affect systemic and visceral perfusion. Rats were injected with either saline (1 ml/kg), zymosan (5 mg/kg) or CVF (5 units/kg) at t = 0 and 30 minutes. Thermodilution cardiac output, mean arterial pressure, heart rate, systemic vascular resistance, and hematocrit were determined at t = 2 hours. Effective hepatic and renal blood flows, by clearance of galactose and p-aminohippurate respectively, were determined over the next hour. The per cent change in total hemolytic complement from t = 0 to t = 3 hours was determined by immune hemolysis of sheep erythrocytes. There was no difference in systemic hemodynamic parameters between the three groups. Hepatic blood flow was depressed in both the zymosan (3.83 +/- 0.23 ml/min/100 g) and CVF (3.72 +/- 0.20 ml/min/100 g) groups compared with controls (4.62 +/- 0.19 ml/min/100 g, P less than 0.05). Renal blood flow in the zymosan-treated group (6.40 +/- 0.24 ml/min/100 g) increased over control (4.80 +/- 0.40 ml/min/100 g, P less than 0.05) but was unchanged in the CVF group (5.06 +/- 0.23 ml/min/100 g). The amount of complement activated correlated with the change in hepatic (r = -0.419, P less than 0.05) but not renal (r = -0.008, P = 0.917) flow. Complement activation may occupy a proximal position in the pathogenesis of hepatic ischemia associated with trauma and sepsis.

  5. Human stem cell-derived retinal epithelial cells activate complement via collectin 11 in response to stress

    DEFF Research Database (Denmark)

    Fanelli, Giorgia; Gonzalez-Cordero, Anai; Gardner, Peter J

    2017-01-01

    Age-related macular degeneration (AMD) is a major cause of blindness and is associated with complement dysregulation. The disease is a potential target for stem cell therapy but success is likely to be limited by the inflammatory response. We investigated the innate immune properties of human ind...

  6. Comprehensive approach to study complement C4 in systemic lupus erythematosus: Gene polymorphisms, protein levels and functional activity

    NARCIS (Netherlands)

    Tsang-A-Sjoe, M. W. P.; Bultink, I. E. M.; Korswagen, L. A.; van der Horst, A. [=Anneke; Rensink, I.; de Boer, M.; Hamann, D.; Voskuyl, A. E.; Wouters, D.

    2017-01-01

    Genetic variation of the genes encoding complement component C4 is strongly associated with systemic lupus erythematosus (SLE), a chronic multi-organ auto-immune disease. This study examined C4 and its isotypes on a genetic, protein, and functional level in 140 SLE patients and 104 healthy controls.

  7. SALO, a novel classical pathway complement inhibitor from saliva of the sand fly Lutzomyia longipalpis.

    Science.gov (United States)

    Ferreira, Viviana P; Fazito Vale, Vladimir; Pangburn, Michael K; Abdeladhim, Maha; Mendes-Sousa, Antonio Ferreira; Coutinho-Abreu, Iliano V; Rasouli, Manoochehr; Brandt, Elizabeth A; Meneses, Claudio; Lima, Kolyvan Ferreira; Nascimento Araújo, Ricardo; Pereira, Marcos Horácio; Kotsyfakis, Michalis; Oliveira, Fabiano; Kamhawi, Shaden; Ribeiro, Jose M C; Gontijo, Nelder F; Collin, Nicolas; Valenzuela, Jesus G

    2016-01-13

    Blood-feeding insects inject potent salivary components including complement inhibitors into their host's skin to acquire a blood meal. Sand fly saliva was shown to inhibit the classical pathway of complement; however, the molecular identity of the inhibitor remains unknown. Here, we identified SALO as the classical pathway complement inhibitor. SALO, an 11 kDa protein, has no homology to proteins of any other organism apart from New World sand flies. rSALO anti-complement activity has the same chromatographic properties as the Lu. longipalpis salivary gland homogenate (SGH)counterparts and anti-rSALO antibodies blocked the classical pathway complement activity of rSALO and SGH. Both rSALO and SGH inhibited C4b deposition and cleavage of C4. rSALO, however, did not inhibit the protease activity of C1s nor the enzymatic activity of factor Xa, uPA, thrombin, kallikrein, trypsin and plasmin. Importantly, rSALO did not inhibit the alternative or the lectin pathway of complement. In conclusion our data shows that SALO is a specific classical pathway complement inhibitor present in the saliva of Lu. longipalpis. Importantly, due to its small size and specificity, SALO may offer a therapeutic alternative for complement classical pathway-mediated pathogenic effects in human diseases.

  8. Intratracheally instilled titanium dioxide nanoparticles translocate to heart and liver and activate complement cascade in the heart of C57BL/6 mice

    DEFF Research Database (Denmark)

    Husain, Mainul; Wu, Dongmei; Saber, Anne T.

    2015-01-01

    translocation from the lungs. Adult female C57BL/6 mice were exposed via intratracheal instillation to 18 or 162 mu g of industrially relevant titanium dioxide nanoparticles (nano-TiO2) alongside vehicle controls. Using the nano-scale hyperspectral microscope, translocation to heart and liver was confirmed...... of translocation are unclear. We employed a nano-scale hyperspectral microscope to spatially observe and spectrally profile NPs in tissues and blood following pulmonary deposition in mice. In addition, we characterized effects occurring in blood, liver and heart at the mRNA and protein level following...... at both doses, and to blood at the highest dose, in mice analyzed 24 h post-exposure. Global gene expression profiling and ELISA analysis revealed activation of complement cascade and inflammatory processes in heart and specific activation of complement factor 3 in blood, suggesting activation of an early...

  9. Complement factor H deficiency and endocapillary glomerulonephritis due to paternal isodisomy and a novel factor H mutation

    DEFF Research Database (Denmark)

    Schejbel, L; Schmidt, I M; Kirchhoff, Eva Maria

    2011-01-01

    Complement factor H (CFH) is a regulator of the alternative complement activation pathway. Mutations in the CFH gene are associated with atypical hemolytic uremic syndrome, membranoproliferative glomerulonephritis type II and C3 glomerulonephritis. Here, we report a 6-month-old CFH-deficient child...

  10. Elevated levels of the complement activation product C4d in bronchial fluids for the diagnosis of lung cancer.

    Directory of Open Access Journals (Sweden)

    Daniel Ajona

    Full Text Available Molecular markers in bronchial fluids may contribute to the diagnosis of lung cancer. We previously observed a significant increase of C4d-containing complement degradation fragments in bronchoalveolar lavage (BAL supernatants from lung cancer patients in a cohort of 50 cases and 22 controls (CUN cohort. The present study was designed to determine the diagnostic performance of these complement fragments (hereinafter jointly referred as C4d in bronchial fluids. C4d levels were determined in BAL supernatants from two independent cohorts: the CU cohort (25 cases and 26 controls and the HUVR cohort (60 cases and 98 controls. A series of spontaneous sputum samples from 68 patients with lung cancer and 10 controls was also used (LCCCIO cohort. Total protein content, complement C4, complement C5a, and CYFRA 21-1 were also measured in all cohorts. C4d levels were significantly increased in BAL samples from lung cancer patients. The area under the ROC curve was 0.82 (95%CI = 0.71-0.94 and 0.67 (95%CI = 0.58-0.76 for the CU and HUVR cohorts, respectively. In addition, unlike the other markers, C4d levels in BAL samples were highly consistent across the CUN, CU and HUVR cohorts. Interestingly, C4d test markedly increased the sensitivity of bronchoscopy in the two cohorts in which cytological data were available (CUN and HUVR cohorts. Finally, in the LCCCIO cohort, C4d levels were higher in sputum supernatants from patients with lung cancer (area under the ROC curve: 0.7; 95%CI = 0.56-0.83. In conclusion, C4d is consistently elevated in bronchial fluids from lung cancer patients and may be used to improve the diagnosis of the disease.

  11. Short Horizon Control Strategies for an Alternating Activated Sludge Process

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard

    1996-01-01

    Three control strategies allowing improved operational flexibility of an alternating type activated sludge process are presented in a unified model based framework. The control handles employed are the addition rate of an external carbon source to denitrification, the cycle length, and the dissol...

  12. Evasion Mechanisms Used by Pathogens to Escape the Lectin Complement Pathway

    DEFF Research Database (Denmark)

    Rosbjerg, Anne; Genster, Ninette; Pilely, Katrine

    2017-01-01

    The complement system is a crucial defensive network that protects the host against invading pathogens. It is part of the innate immune system and can be initiated via three pathways: the lectin, classical and alternative activation pathway. Overall the network compiles a group of recognition...... the level of activity. The result is a pro-inflammatory response meant to combat foreign microbes. Microbial elimination is, however, not a straight forward procedure; pathogens have adapted to their environment by evolving a collection of evasion mechanisms that circumvent the human complement system....... Complement evasion strategies features different ways of exploiting human complement proteins and moreover features different pathogen-derived proteins that interfere with the normal processes. Accumulated, these mechanisms target all three complement activation pathways as well as the final common part...

  13. Methylation of the phosphate oxygen moiety of phospholipid-methoxy(polyethylene glycol) conjugate prevents PEGylated liposome-mediated complement activation and anaphylatoxin production

    DEFF Research Database (Denmark)

    Moghimi, S.M.; Hamad, I.; Andresen, Thomas Lars

    2006-01-01

    Methoxy(polyethylene glycol), mPEG, -grafted liposomes are known to exhibit prolonged circulation time in the blood, but their infusion into a substantial percentage of human subjects triggers immediate non-IgE-mediated hypersensitivity reactions. These reactions are strongly believed to arise from...... to PEGylated liposome-mediated complement activation. Our findings provide a rational conceptual basis for development of safer vesicles for site-specific drug delivery and controlled release at pathological sites....

  14. Solid-phase classical complement activation by C-reactive protein (CRP) is inhibited by fluid-phase CRP-C1q interaction

    International Nuclear Information System (INIS)

    Sjoewall, Christopher; Wetteroe, Jonas; Bengtsson, Torbjoern; Askendal, Agneta; Almroth, Gunnel; Skogh, Thomas; Tengvall, Pentti

    2007-01-01

    C-reactive protein (CRP) interacts with phosphorylcholine (PC), Fcγ receptors, complement factor C1q and cell nuclear constituents, yet its biological roles are insufficiently understood. The aim was to characterize CRP-induced complement activation by ellipsometry. PC conjugated with keyhole limpet hemocyanin (PC-KLH) was immobilized to cross-linked fibrinogen. A low-CRP serum with different amounts of added CRP was exposed to the PC-surfaces. The total serum protein deposition was quantified and deposition of IgG, C1q, C3c, C4, factor H, and CRP detected with polyclonal antibodies. The binding of serum CRP to PC-KLH dose-dependently triggered activation of the classical pathway. Unexpectedly, the activation was efficiently down-regulated at CRP levels >150 mg/L. Using radial immunodiffusion, CRP-C1q interaction was observed in serum samples with high CRP concentrations. We propose that the underlying mechanism depends on fluid-phase interaction between C1q and CRP. This might constitute another level of complement regulation, which has implications for systemic lupus erythematosus where CRP is often low despite flare-ups

  15. CSF coccidioides complement fixation

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003526.htm CSF coccidioides complement fixation test To use the sharing features on this page, please enable JavaScript. CSF coccidioides complement fixation is a test that checks ...

  16. Natural IgM antibodies that bind neoepitopes exposed as a result of spinal cord injury , drive secondary injury by activating complement.

    Science.gov (United States)

    Narang, Aarti; Qiao, Fei; Atkinson, Carl; Zhu, Hong; Yang, Xiaofeng; Kulik, Liudmila; Holers, V Michael; Tomlinson, Stephen

    2017-06-19

    Natural IgM antibodies (Abs) function as innate immune sensors of injury via recognition of neoepitopes expressed on damaged cells, although how this recognition systems function following spinal cord injury (SCI) exposes various neoepitopes and their precise nature remains largely unknown. Here, we investigated the role of two natural IgM monoclonal Abs (mAbs), B4 and C2, that recognize post-ischemic neoepitopes following ischemia and reperfusion in other tissues. Identification of post-SCI expressed neoepitopes was examined using previously characterized monoclonal Abs (B4 and C2 mAbs). The role of post-SCI neoepitopes and their recognition by natural IgM Abs in propagating secondary injury was examined in Ab-deficient Rag1-/- or wild type C57BL/6 mice using Ab reconstitution experiments and neoepitope-targeted therapeutic studies, respectively. Administration of B4 or C2 mAb following murine SCI increased lesion size and worsened functional outcome in otherwise protected Ab-deficient Rag1-/- mice. Injury correlated with colocalized deposition of IgM and C3d in injured spinal cords from both mAb reconstituted Rag1-/- mice and untreated wild-type mice. Depletion of peritoneal B1 B cells, a source of natural Abs, reduced circulating levels of IgM with B4 (annexin-IV) and C2 (subset of phospholipids) reactivity, reduced IgM and complement deposition in the spinal cord, and protected against SCI. We therefore investigated whether the B4 neoepitope represents a therapeutic target for complement inhibition. B4-Crry, a fusion protein consisting of a single-chain Ab derived from B4 mAb, linked to the complement inhibitor Crry, significantly protected against SCI. B4-Crry exhibited a dual function in that it inhibited both the binding of pathogenic IgM and blocked complement activation in the spinal cord. This study identifies important neoepitopes expressed within the spinal cord after injury. These neoepitopes are recognized by clonally specific natural IgM Abs that

  17. Specificity of EIA immunoassay for complement factor Bb testing.

    Science.gov (United States)

    Pavlov, Igor Y; De Forest, Nikol; Delgado, Julio C

    2011-01-01

    During the alternative complement pathway activation, factor B is cleaved in two fragments, Ba and Bb. Concentration of those fragments is about 2 logs lower than of factor B present in the blood, which makes fragment detection challenging because of potential cross-reactivity. Lack of information on Bb assay cross-reactivity stimulated the authors to investigate this issue. We ran 109 healthy donor EDTA plasmas and 80 sera samples with both factor B immunodiffusion (The Binding Site) and Quidel Bb EIA assays. During the study it was shown that physiological concentrations of gently purified factor B demonstrated approximately 0.15% cross-reactivity in the Quidel Bb EIA assay. We also observed that Bb concentration in serum is higher than in plasma due to complement activation during clot formation which let us use sera as samples representing complement activated state. Our study demonstrated that despite the potential 0.15% cross-reactivity between endogenous factor B and cleaved Bb molecule, measuring plasma concentrations of factor Bb is adequate to evaluate the activation of the alternative complement pathway.

  18. Complement: Alive and Kicking Nanomedicines

    DEFF Research Database (Denmark)

    Andersen, Alina Joukainen; Hashemi, S.H.; Andresen, Thomas Lars

    2009-01-01

    Administration of liposome- and polymer-based clinical nanomedicines, as well as many other proposed multifunctional nanoparticles, often triggers hypersensitivity reactions without the involvement of IgE. These anaphylactic reactions are believed to be secondary to activation of the complement...... their procoagulant activity, and has the capacity to elicit non-lytic stimulatory responses from vascular endothelial cells. Here we discuss the molecular basis of complement activation by liposomes, including poly(ethylene glycol) coated vesicles, and other related lipid-based and phospholipid-poly(ethylene glycol...

  19. Complementing Gender Analysis Methods.

    Science.gov (United States)

    Kumar, Anant

    2016-01-01

    The existing gender analysis frameworks start with a premise that men and women are equal and should be treated equally. These frameworks give emphasis on equal distribution of resources between men and women and believe that this will bring equality which is not always true. Despite equal distribution of resources, women tend to suffer and experience discrimination in many areas of their lives such as the power to control resources within social relationships, and the need for emotional security and reproductive rights within interpersonal relationships. These frameworks believe that patriarchy as an institution plays an important role in women's oppression, exploitation, and it is a barrier in their empowerment and rights. Thus, some think that by ensuring equal distribution of resources and empowering women economically, institutions like patriarchy can be challenged. These frameworks are based on proposed equality principle which puts men and women in competing roles. Thus, the real equality will never be achieved. Contrary to the existing gender analysis frameworks, the Complementing Gender Analysis framework proposed by the author provides a new approach toward gender analysis which not only recognizes the role of economic empowerment and equal distribution of resources but suggests to incorporate the concept and role of social capital, equity, and doing gender in gender analysis which is based on perceived equity principle, putting men and women in complementing roles that may lead to equality. In this article the author reviews the mainstream gender theories in development from the viewpoint of the complementary roles of gender. This alternative view is argued based on existing literature and an anecdote of observations made by the author. While criticizing the equality theory, the author offers equity theory in resolving the gender conflict by using the concept of social and psychological capital.

  20. Analysis of alternatives for immobilized low activity waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Burbank, D.A.

    1997-10-28

    This report presents a study of alternative disposal system architectures and implementation strategies to provide onsite near-surface disposal capacity to receive the immobilized low-activity waste produced by the private vendors. The analysis shows that a flexible unit strategy that provides a suite of design solutions tailored to the characteristics of the immobilized low-activity waste will provide a disposal system that best meets the program goals of reducing the environmental, health, and safety impacts; meeting the schedule milestones; and minimizing the life-cycle cost of the program.

  1. Analysis of alternatives for immobilized low-activity waste disposal

    International Nuclear Information System (INIS)

    Burbank, D.A.

    1997-01-01

    This report presents a study of alternative disposal system architectures and implementation strategies to provide onsite near-surface disposal capacity to receive the immobilized low-activity waste produced by the private vendors. The analysis shows that a flexible unit strategy that provides a suite of design solutions tailored to the characteristics of the immobilized low-activity waste will provide a disposal system that best meets the program goals of reducing the environmental, health, and safety impacts; meeting the schedule milestones; and minimizing the life-cycle cost of the program

  2. The membrane attack complex of complement contributes to plasmin-induced synthesis of platelet-activating factor by endothelial cells and neutrophils.

    Science.gov (United States)

    Lupia, Enrico; Del Sorbo, Lorenzo; Bergerone, Serena; Emanuelli, Giorgio; Camussi, Giovanni; Montrucchio, Giuseppe

    2003-08-01

    Thrombolytic agents, used to restore blood flow to ischaemic tissues, activate several enzymatic systems with pro-inflammatory effects, thus potentially contributing to the pathogenesis of ischaemia-reperfusion injury. Platelet-activating factor (PAF), a phospholipid mediator of inflammation, has been implicated in the pathogenesis of this process. We previously showed that the infusion of streptokinase (SK) induces the intravascular release of PAF in patients with acute myocardial infarction (AMI), and that cultured human endothelial cells (EC) synthesized PAF in response to SK and plasmin (PLN). In the present study, we investigated the role of the membrane attack complex (MAC) of complement in the PLN-induced synthesis of PAF. In vivo, we showed a correlation between the levels of soluble terminal complement components (sC5b-9) and the concentrations of PAF detected in blood of patients with AMI infused with SK. In vitro both EC and polymorphonuclear neutrophils (PMN), incubated in the presence of PLN and normal human serum, showed an intense staining for the MAC neoepitope, while no staining was detected when they were incubated with PLN in the presence of heat-inactivated normal human serum. Moreover, the insertion of MAC on EC and PMN plasmamembrane elicited the synthesis of PAF. In conclusion, our results elucidate the mechanisms involved in PAF production during the activation of the fibrinolytic system, showing a role for complement products in this setting. The release of PAF may increase the inflammatory response, thus limiting the beneficial effects of thrombolytic therapy. Moreover, it may have a pathogenic role in other pathological conditions, such as transplant rejection, tumoral angiogenesis, and septic shock, where fibrinolysis is activated.

  3. Dynamics of human complement-mediated killing of Klebsiella pneumoniae.

    Science.gov (United States)

    Nypaver, Christina M; Thornton, Margaret M; Yin, Suellen M; Bracho, David O; Nelson, Patrick W; Jones, Alan E; Bortz, David M; Younger, John G

    2010-11-01

    With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacterial metabolic activity in near-real-time, we investigated the dynamics of complement-mediated attack in healthy individuals and in patients presenting to the emergency department with community-acquired severe sepsis. A novel mathematical/statistical model was developed to simplify light output trajectories over time into two fitted parameters, the rate of complement activation and the delay from activation to the onset of killing. Using Factor B-depleted serum, the alternative pathway was found to be the primary bactericidal effector: In the absence of B, C3 opsonization as measured by flow cytometry did not progress and bacteria proliferated near exponentially. Defects in bacterial killing were easily demonstrable in patients with severe sepsis compared with healthy volunteers. In most patients with sepsis, the rate of activation was higher than in normal subjects but was associated with a prolonged delay between activation and bacterial killing (P < 0.05 for both). Theoretical modeling suggested that this combination of accentuated but delayed function should allow successful bacterial killing but with significantly greater complement activation. The use of luminescent bacteria allowed for the development of a novel and powerful tool for assessing complement immunology for the purposes of mechanistic study and patient evaluation.

  4. Age-Related Macular Degeneration: A Connection between Human Herpes Virus-6A-Induced CD46 Downregulation and Complement Activation?

    Directory of Open Access Journals (Sweden)

    Walter Fierz

    2017-10-01

    Full Text Available Viruses are able to interfere with the immune system by docking to receptors on host cells that are important for proper functioning of the immune system. A well-known example is the human immunodeficiency virus that uses CD4 cell surface molecules to enter host lymphocytes and thereby deleteriously destroying the helper cell population of the immune system. A more complicated mechanism is seen in multiple sclerosis (MS where human herpes virus-6A (HHV-6A infects astrocytes by docking to the CD46 surface receptor. Such HHV-6A infection in the brain of MS patients has recently been postulated to enable Epstein–Barr virus (EBV to transform latently infected B-lymphocytes in brain lesions leading to the well-known phenomenon of oligoclonal immunoglobulin production that is widely used in the diagnosis of MS. The cellular immune response to HHV-6A and EBV is one part of the pathogenic mechanisms in MS. A more subtle pathogenic mechanism can be seen in the downregulation of CD46 on astrocytes by the infecting HHV-6A. Since CD46 is central in regulating the complement system, a lack of CD46 can lead to hyperactivation of the complement system. In fact, activation of the complement system in brain lesions is a well-known pathogenic mechanism in MS. In this review, it is postulated that a similar mechanism is central in the development of age-related macular degeneration (AMD. One of the earliest changes in the retina of AMD patients is the loss of CD46 expression in the retinal pigment epithelial (RPE cells in the course of geographic atrophy. Furthermore, CD46 deficient mice spontaneously develop dry-type AMD-like changes in their retina. It is also well known that certain genetic polymorphisms in the complement-inhibiting pathways correlate with higher risks of AMD development. The tenet is that HHV-6A infection of the retina leads to downregulation of CD46 and consequently to hyperactivation of the complement system in the eyes of susceptible

  5. An integrated assessment of morphology, size, and complement activation of the PEGylated liposomal doxorubicin products Doxil®, Caelyx®, DOXOrubicin, and SinaDoxosome

    DEFF Research Database (Denmark)

    Wibroe, Peter P; Ahmadvand, Davoud; Oghabian, Mohammad Ali

    2016-01-01

    follow-on products DOXOrubicin (approved by the US Food and Drug Administration) and SinaDoxosome (produced in Iran) by cryogenic transmission electron microscopy, dynamic light scattering and Nanoparticle Tracking Analysis, and assess their potential in activating the complement system in human sera. We...... found subtle physicochemical differences between the tested liposomal products and even between the tested batches of Doxil® and Caelyx®. Notably, these included differences in vesicular population aspect ratios and particle number. Among the tested products, only SinaDoxosome, in addition...

  6. Characterization of vanadate-dependent NADH oxidation activity and isolation of yeast DNA which complements a class 1 vanadate resistance mutation

    International Nuclear Information System (INIS)

    Minasi, L.E.

    1989-01-01

    A vanadate-dependent NADH oxidation activity has been characterized in plasma membranes from the yeast S cerevisiae. NADH oxidation activity was maximally stimulated at pH 5.0 in phosphate buffer. NADH oxidation was not dependent on the concentration of plasma membranes. The vanadate-dependent NADH oxidation activity was abolished under anaerobic conditions and the concomitant uptake of oxygen occurred during NADH oxidation. The activity was inhibited by superoxide dismutase and stimulated by the presence of paraquat. These results indicate that the vanadate stimulation of NADH oxidation in yeast plasma membranes occurs as a result of the vanadate-dependent oxidation of NADH by superoxide, generated by a plasma membrane NADH oxidase. 51 V-NMR results indicated that a phosphate-vanadate anhydride was the stimulatory species in pH 5.0 and pH 7.0 phosphate buffer. Yeast DNA has been isolated which complements a class 1 vanadate resistance mutation

  7. Complement activation capacity in plasma before and during high-dose prednisolone treatment and tapering in exacerbations of Crohn's disease and ulcerative colitis

    Directory of Open Access Journals (Sweden)

    Baatrup Gunnar

    2005-09-01

    Full Text Available Abstract Background Ulcerative colitis (UC and Crohn's disease (CD are characterized by intestinal inflammation mainly caused by a disturbance in the balance between cytokines and increased complement (C activation. Our aim was to evaluate possible associations between C activation capacity and prednisolone treatment. Methods Plasma from patients with exacerbations of UC (n = 18 or CD (n = 18 were collected before and during high dose prednisolone treatment (1 mg/kg body weight and tapering. Friedman's two way analysis of variance, Mann-Whitney U test and Wilcoxon signed-rank sum test were used Results Before treatment, plasma from CD patients showed significant elevations in all C-mediated analyses compared to the values obtained from 38 healthy controls (p Conclusion Our findings indicate that C activation capacity is up-regulated significantly in plasma from CD patients. The decreases observed after prednisolone treatment reflect a general down-regulation in immune activation.

  8. Comprehensive approach to study complement C4 in systemic lupus erythematosus: Gene polymorphisms, protein levels and functional activity.

    Science.gov (United States)

    Tsang-A-Sjoe, M W P; Bultink, I E M; Korswagen, L A; van der Horst, A; Rensink, I; de Boer, M; Hamann, D; Voskuyl, A E; Wouters, D

    2017-12-01

    Genetic variation of the genes encoding complement component C4 is strongly associated with systemic lupus erythematosus (SLE), a chronic multi-organ auto-immune disease. This study examined C4 and its isotypes on a genetic, protein, and functional level in 140 SLE patients and 104 healthy controls. Gene copy number (GCN) variation, silencing CT-insertion, and the retroviral HERV-K(C4) insertion) were analyzed with multiplex ligation-dependent probe amplification. Increased susceptibility to SLE was found for low GCN (≪2) of C4A. Serositis was the only clinical manifestation associated with low C4A GCN. One additional novel silencing mutation in the C4A gene was found by Sanger sequencing. This mutation causes a premature stop codon in exon 11. Protein concentrations of C4 isoforms C4A and C4B were determined with ELISA and were significantly lower in SLE patients compared to healthy controls. To study C4 isotypes on a functional level, a new C4 assay was developed, which distinguishes C4A from C4B by its binding capacity to amino or hydroxyl groups, respectively. This assay showed high correlation with ELISA and detected crossing over of Rodgers and Chido antigens in 3.2% (8/244) of individuals. The binding capacity of available C4 to its substrates was unaffected in SLE. Our study provides, for the first time, a complete overview of C4 in SLE from genetic variation to binding capacity using a novel test. As this test detects crossing over of Rodgers and Chido antigens, it will allow for more accurate measurement of C4 in future studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. N-terminal prodomain of Pfs230 synthesized using a cell-free system is sufficient to induce complement-dependent malaria transmission-blocking activity.

    Science.gov (United States)

    Tachibana, Mayumi; Wu, Yimin; Iriko, Hideyuki; Muratova, Olga; MacDonald, Nicholas J; Sattabongkot, Jetsumon; Takeo, Satoru; Otsuki, Hitoshi; Torii, Motomi; Tsuboi, Takafumi

    2011-08-01

    The aim of a malaria transmission-blocking vaccine is to block the development of malaria parasites in the mosquito and thus prevent subsequent infection of the human host. Previous studies have demonstrated that the gametocyte/gamete surface protein Pfs230 can induce transmission-blocking immunity and have evaluated Escherichia coli-produced Pfs230 as a transmission-blocking vaccine candidate. In this study, we used the wheat germ cell-free expression system to produce N-terminal fragments of Pfs230 and evaluated the transmission-blocking activity of antisera raised against the recombinant Pfs230 protein. The rabbit antisera reacted to the surface of cultured gametocytes and gametes of the Plasmodium falciparum NF54 line, recognized the 360-kDa form of parasite-produced Pfs230 by Western blot assay, and reduced the infectivity of NF54 parasites to Anopheles stefensi mosquitoes in the presence of complement in a standard membrane feeding assay. Thus, our data demonstrate that the N-terminal pro domain of Pfs230 is sufficient to induce complement-dependent transmission-blocking activity against P. falciparum.

  10. Coordinated Expression of Borrelia burgdorferi Complement Regulator-Acquiring Surface Proteins during the Lyme Disease Spirochete's Mammal-Tick Infection Cycle▿

    OpenAIRE

    Bykowski, Tomasz; Woodman, Michael E.; Cooley, Anne E.; Brissette, Catherine A.; Brade, Volker; Wallich, Reinhard; Kraiczy, Peter; Stevenson, Brian

    2007-01-01

    The Lyme disease spirochete, Borrelia burgdorferi, is largely resistant to being killed by its hosts’ alternative complement activation pathway. One possible resistance mechanism of these bacteria is to coat their surfaces with host complement regulators, such as factor H. Five different B. burgdorferi outer surface proteins having affinities for factor H have been identified: complement regulator-acquiring surface protein 1 (BbCRASP-1), encoded by cspA; BbCRASP-2, encoded by cspZ; and three ...

  11. Serum complement changes during double-blind food challenges in children with a history of food sensitivity.

    Science.gov (United States)

    Martin, M E; Guthrie, L A; Bock, S A

    1984-04-01

    Serum levels of C3, C4, factor B, properdin, total hemolytic complement and alternative-pathway hemolytic activity were measured before and after double-blind food challenge in 23 children with impressive histories of adverse reactions to foods. The 23 subjects had 11 positive food challenges and 12 negative food challenges. Nine patients with reagin-mediated positive food challenges showed increases in all six complement assays after double-blind food challenge, while the group with negative food challenges showed decreases in five of the six assays. The difference between the two groups for complement changes after double-blind food challenge was significant only for the alternative-pathway assay. Individual subject analysis revealed markedly heterogeneous changes in direction and magnitude within both groups for all complement assays. Therefore, it is concluded that measurement of serum complement levels is not a useful test for the clinical evaluation of a patient with suspected food sensitivity.

  12. Complement factor H family proteins in their non-canonical role as modulators of cellular functions.

    Science.gov (United States)

    Józsi, Mihály; Schneider, Andrea E; Kárpáti, Éva; Sándor, Noémi

    2018-01-04

    Complement factor H is a major regulator of the alternative pathway of the complement system. The factor H-related proteins are less characterized, but recent data indicate that they rather promote complement activation. These proteins have some common ligands with factor H and have both overlapping and distinct functions depending on domain composition and the degree of conservation of amino acid sequence. Factor H and some of the factor H-related proteins also appear in a non-canonical function that is beyond their role in the modulation of complement activation. This review covers our current understanding on this emerging role of factor H family proteins in modulating the activation and function of various cells by binding to receptors or receptor ligands. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Physical activity recommendations: an alternative approach using energy expenditure.

    Science.gov (United States)

    Mudd, Lanay M; Rafferty, Ann P; Reeves, Mathew J; Pivarnik, James M

    2008-10-01

    Most adults do not meet the American College of Sports Medicine and Centers for Disease Control and Prevention (ACSM/CDC) physical activity recommendations. Even fewer meet the more extreme Institute of Medicine (IOM) physical activity recommendations. Compliance with either recommendation has been conventionally assessed by combining frequencies and durations of self-reported activities. Leisure-time energy expenditure is a cumulative measure of activity that offers an alternative method of defining compliance. To calculate the leisure-time energy expenditure of adults complying with the ACSM/CDC or the IOM physical activity recommendations determined by conventional measures and to reexamine compliance with the IOM recommendation using energy expenditure criteria. National, cross-sectional data from the 2000 Behavioral Risk Factor Surveillance System determined the mode, frequency, and duration of up to two leisure-time activities performed by adults. Four mutually exclusive activity groups (Non-, Low-, ACSM/CDC-, and IOM-Active) were defined on the basis of frequencies and durations of reported activities. Leisure-time energy expenditure (kcal x kg(-1) x wk(-1)) was calculated per respondent. The energy expenditure threshold for meeting the IOM recommendation was calculated as 21 kcal x kg(-1) x wk(-1). Of the 162,669 respondents included in the analyses, 29.9% were Nonactive, whereas 42.3%, 23.3%, and 4.5% were Low-, ACSM/CDC-, and IOM-Active, respectively. Median leisure-time energy expenditure values were 9.0, 27.4, and 63.0 kcal x kg(-1) x wk(-1) for Low-, ACSM/CDC-, and IOM-Active groups, respectively. When using energy expenditure criteria, compliance with the IOM recommendation rose to 27.7% of respondents. Compliance with the IOM physical activity recommendation dramatically increased when assessed by energy expenditure compared with conventional criteria, thereby highlighting the potential bias of conventional methods. A significant proportion of adults

  14. The Complement System: A Prey of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Kárita C. F. Lidani

    2017-04-01

    Full Text Available Trypanosoma cruzi is a protozoan parasite known to cause Chagas disease (CD, a neglected sickness that affects around 6–8 million people worldwide. Originally, CD was mainly found in Latin America but more recently, it has been spread to countries in North America, Asia, and Europe due the international migration from endemic areas. Thus, at present CD represents an important concern of global public health. Most of individuals that are infected by T. cruzi may remain in asymptomatic form all lifelong, but up to 40% of them will develop cardiomyopathy, digestive mega syndromes, or both. The interaction between the T. cruzi infective forms and host-related immune factors represents a key point for a better understanding of the physiopathology of CD. In this context, the complement, as one of the first line of host defense against infection was shown to play an important role in recognizing T. cruzi metacyclic trypomastigotes and in controlling parasite invasion. The complement consists of at least 35 or more plasma proteins and cell surface receptors/regulators, which can be activated by three pathways: classical (CP, lectin (LP, and alternative (AP. The CP and LP are mainly initiated by immune complexes or pathogen-associated molecular patterns (PAMPs, respectively, whereas AP is spontaneously activated by hydrolysis of C3. Once activated, several relevant complement functions are generated which include opsonization and phagocytosis of particles or microorganisms and cell lysis. An important step during T. cruzi infection is when intracellular trypomastigotes are release to bloodstream where they may be target by complement. Nevertheless, the parasite uses a sequence of events in order to escape from complement-mediated lysis. In fact, several T. cruzi molecules are known to interfere in the initiation of all three pathways and in the assembly of C3 convertase, a key step in the activation of complement. Moreover, T. cruzi promotes secretion

  15. Changing University Students’ Alternative Conceptions of Optics by Active Learning

    Directory of Open Access Journals (Sweden)

    Zalkida Hadžibegović

    2013-01-01

    Full Text Available Active learning is individual and group participation in effective activities such as in-class observing, writing, experimenting, discussion, solving problems, and talking about to-be-learned topics. Some instructors believe that active learning is impossible, or at least extremely difficult to achieve in large lecture sessions. Nevertheless, the truly impressive implementation results of theSCALE-UP learning environment suggest that such beliefs are false (Beichner et al., 2000. In this study, we present a design of an active learning environment with positive effect on students. The design is based on the following elements: (1 helping students to learn from interactive lecture experiment; (2 guiding students to use justified explanation and prediction after observing and exploring a phenomenon; (3 developing a conceptual question sequencedesigned for use in an interactive lecture with students answering questions in worksheets by writing and drawing; (4 evaluating students’ conceptual change and gains by questions related to light reflection, refraction, and image formation in an exam held a week after the active learning session. Data were collected from 95 science freshmen with different secondary school backgrounds. They participated in geometrical optics classes organized for collecting research results during and after only one active learning session.The results have showed that around 60% of the students changed their initial alternative conceptions of vision and of image formation. It was also found that a large group of university students is likely to be engaged in active learning, shifting from a passive role they usually play during teacher’s lectures.

  16. Noun complement clauses as referential modifiers

    Directory of Open Access Journals (Sweden)

    Carlos de Cuba

    2017-01-01

    Full Text Available A number of recent analyses propose that so-called noun complement clauses should be analyzed as a type of relative clause. In this paper, I present a number of complications for any analysis that equates noun complement clauses to relative clauses, and conclude that this type of analysis is on the wrong track. I present cross-linguistic evidence showing that the syntactic behavior of noun complement clauses does not pattern with relative clauses. Patterns of complementizer choice and complementizer drop as well as patterns involving main clause phenomena and extraction differ in the two constructions, which I argue is unexpected under a relative clause analysis that involves operator movement. Instead I present an alternative analysis in which I propose that the referentiality of a noun complement clause is linked to its syntactic behavior. Following recent work, I claim that referential clauses have a syntactically truncated left-periphery, and this truncation can account for the lack of main clause phenomena in noun complement clauses. I argue that the truncation analysis is also able to accommodate complementizer data patterns more easily than relative clause analyses that appeal to operator movement.

  17. Growth, serum biochemistry, complement activity, and liver gene expression responses of Pekin ducklings to graded levels of cultured aflatoxin B1.

    Science.gov (United States)

    Chen, X; Horn, N; Cotter, P F; Applegate, T J

    2014-08-01

    A 14-d study was conducted to evaluate the effects of cultured aflatoxin B1 (AFB1) on performance, serum biochemistry, serum natural antibody and complement activity, and hepatic gene expression parameters in Pekin ducklings. A total of 144 male Pekin ducklings were weighed, tagged, and randomly allotted to 4 dietary treatments containing 4 concentrations of AFB1 (0, 0.11, 0.14, and 0.21 mg/kg) from 0 to 14 d of age (6 cages per diet; 6 ducklings per cage). Compared with the control group, there was a 10.9, 31.7, and 47.4% (P feed efficiency was not affected. Increasing concentrations of AFB1 reduced cumulative BW gain and feed intake both linearly and quadratically, and regression equations were developed with r(2) ≥0.73. Feeding 0.11 to 0.21 mg of AFB1/kg reduced serum glucose, creatinine, albumin, total protein, globulin, Ca, P, and creatine phosphokinase linearly, whereas serum urea N, Cl, alkaline phosphatase, and aspartate amino transferase concentrations increased linearly with increasing AFB1 (P complement pathways in the duckling serum when tested by lysis of rabbit, human type O, and horse erythrocytes, and decreased rabbit and horse agglutinins (P feed intake and BW gain decrease approximately 230 and 169 g per duckling from hatch to 14 d; and that AFB1 at very low concentrations can significantly impair liver function and gene expression, and innate immune dynamics in Pekin ducklings. © Poultry Science Association Inc.

  18. Reduction in erythrocyte-bound complement activation products and titres of anti-C1q antibodies associate with clinical improvement in systemic lupus erythematosus.

    Science.gov (United States)

    Buyon, Jill; Furie, Richard; Putterman, Chaim; Ramsey-Goldman, Rosalind; Kalunian, Kenneth; Barken, Derren; Conklin, John; Dervieux, Thierry

    2016-01-01

    The relationship between cell-bound complement activation products (CB-CAPs: EC4d, EC3d), anti-C1q, soluble complement C3/C4 and disease activity in systemic lupus erythematosus (SLE) was evaluated. Per protocol, at baseline all SLE subjects enrolled in this longitudinal study presented with active disease and elevated CB-CAPs. At each monthly visit, the non-serological (ns) Safety of Estrogens in Lupus Erythematosus: National Assessment (SELENA-SLEDAI) and the British Isles Lupus Assessment Group (BILAG)-2004 index scores were determined as was a random urinary protein to creatinine ratio (uPCR). Short-form 36 (SF-36) questionnaires were also collected. All soluble markers were determined using immunoassays, while EC4d and EC3d were determined using flow cytometry. Statistical analysis consisted of linear mixed models with random intercept and fixed slopes. A total of 36 SLE subjects (mean age 34 years; 94% female) were enrolled and evaluated monthly for an average 11 visits per subject. Clinical improvements were observed during the study, with significant decreases in ns-SELENA-SLEDAI scores, BILAG-2004 index scores and uPCR, and increases in all domains of SF-36 (pimprovements in at least six out of the eight domains of SF-36 and outperformed C3/C4. Anti-dsDNA titres did not correlate with changes in disease activity. These data indicate that CB-CAPs and anti-C1q are helpful in monitoring patients with SLE.

  19. Complement elevation in spinal cord injury.

    Science.gov (United States)

    Rebhun, J; Botvin, J

    1980-05-01

    Laboratory studies revealed an elevated complement in 66% of patients with spinal cord injury. It is postulated that the activated complement may be a component of self-feeding immunological mechanism responsible for the failure of regeneration of a mature mammalian spinal cord. There was no evidence that such an injury had any effect on pre-existing atopy.

  20. Viral mimicry of the complement system

    Indian Academy of Sciences (India)

    The complement system is a potent innate immune mechanism consisting of cascades of proteins which are designed to fight against and annul intrusion of all the foreign pathogens. Although viruses are smaller in size and have relatively simple structure, they are not immune to complement attack. Thus, activation of the ...

  1. Complement Receptor 3-Mediated Inhibition of Inflammasome Priming by Ras GTPase-Activating Protein During Francisella tularensis Phagocytosis by Human Mononuclear Phagocytes

    Directory of Open Access Journals (Sweden)

    Ky V. Hoang

    2018-03-01

    Full Text Available Francisella tularensis is a remarkably infectious facultative intracellular bacterium of macrophages that causes tularemia. Early evasion of host immune responses contributes to the success of F. tularensis as a pathogen. F. tularensis entry into human monocytes and macrophages is mediated by the major phagocytic receptor, complement receptor 3 (CR3, CD11b/CD18. We recently determined that despite a significant increase in macrophage uptake following C3 opsonization of the virulent Type A F. tularensis spp. tularensis Schu S4, this phagocytic pathway results in limited pro-inflammatory cytokine production. Notably, MAP kinase/ERK activation is suppressed immediately during C3-opsonized Schu S4-CR3 phagocytosis. A mathematical model of CR3-TLR2 crosstalk predicted early involvement of Ras GTPase-activating protein (RasGAP in immune suppression by CR3. Here, we link CR3-mediated uptake of opsonized Schu S4 by human monocytes and macrophages with inhibition of early signal 1 inflammasome activation, evidenced by limited caspase-1 cleavage and IL-18 release. This inhibition is due to increased RasGAP activity, leading to a reduction in the Ras-ERK signaling cascade upstream of the early inflammasome activation event. Thus, our data uncover a novel signaling pathway mediated by CR3 following engagement of opsonized virulent F. tularensis to limit inflammasome activation in human phagocytic cells, thereby contributing to evasion of the host innate immune system.

  2. Variability of biological effects of silicas: Different degrees of activation of the fifth component of complement by amorphous silicas

    International Nuclear Information System (INIS)

    Governa, Mario; Amati, Monica; Fenoglio, Ivana; Valentino, Matteo; Coloccini, Sabrina; Bolognini, Lucia; Carlo Botta, Gian; Emanuelli, Monica; Pierella, Francesca; Volpe, Anna Rita; Astolfi, Paola; Carmignani, Marco; Fubini, Bice

    2005-01-01

    A biogenic and a pyrogenic amorphous silica were incubated in normal human plasma and compared on a per unit surface basis for their ability to split C5 molecules and yield small C5a peptides. Since C5a peptides induce selective chemotactic attraction of polymorphonuclear leukocytes (PMN), measurement of PMN-induced chemotaxis was used as an index of C5 activation. Though to a lesser extent than the crystalline forms, amorphous silicas can promote the cleavage of C5 protein and generation of C5a-like fragment. The biogenic silica, which differs from the pyrogenic variety in particle shape, level of contaminants, and degree of surface hydrophilicity, besides specific surface, induced a greater response. Both silicas activated C5 through a process which seems to involve multiple events similar to those induced by crystalline silica. C5 molecules are adsorbed and hydroxyl radicals are generated through Haber Weiss cycles catalyzed by the redox-active iron present at the particle surface either as trace impurities or chelated from plasma by silanol groups. In turn, these radicals convert native C5 to an oxidized C5-like form C5(H 2 O 2 ). Finally, C5(H 2 O 2 ) is cleaved by protease enzymatic action of plasma kallikrein activated by the same silica dusts, yielding a product, C5a(H 2 O 2 ), having the same functional characteristic as C5a

  3. Self-association and domain rearrangements between complement C3 and C3u provide insight into the activation mechanism of C3.

    Science.gov (United States)

    Li, Keying; Gor, Jayesh; Perkins, Stephen J

    2010-10-01

    Component C3 is the central protein of the complement system. During complement activation, the thioester group in C3 is slowly hydrolysed to form C3u, then the presence of C3u enables the rapid conversion of C3 into functionally active C3b. C3u shows functional similarities to C3b. To clarify this mechanism, the self-association properties and solution structures of C3 and C3u were determined using analytical ultracentrifugation and X-ray scattering. Sedimentation coefficients identified two different dimerization events in both proteins. A fast dimerization was observed in 50 mM NaCl but not in 137 mM NaCl. Low amounts of a slow dimerization was observed for C3u and C3 in both buffers. The X-ray radius of gyration RG values were unchanged for both C3 and C3u in 137 mM NaCl, but depend on concentration in 50 mM NaCl. The C3 crystal structure gave good X-ray fits for C3 in 137 mM NaCl. By randomization of the TED (thioester-containing domain)/CUB (for complement protein subcomponents C1r/C1s, urchin embryonic growth factor and bone morphogenetic protein 1) domains in the C3b crystal structure, X-ray fits showed that the TED/CUB domains in C3u are extended and differ from the more compact arrangement of C3b. This TED/CUB conformation is intermediate between those of C3 and C3b. The greater exposure of the TED domain in C3u (which possesses the hydrolysed reactive thioester) accounts for the greater self-association of C3u in low-salt conditions. This conformational variability of the TED/CUB domains would facilitate their interactions with a broad range of antigenic surfaces. The second dimerization of C3 and C3u may correspond to a dimer observed in one of the crystal structures of C3b.

  4. Effects of experimentally increased in ovo lysozyme on egg hatchability, chicks complement activity, and phenotype in a precocial bird

    Czech Academy of Sciences Publication Activity Database

    Javůrková, Veronika; Krkavcová, E.; Kreisinger, J.; Hyršl, P.; Hyánková, L.

    2015-01-01

    Roč. 323, č. 8 (2015), s. 497-505 ISSN 1932-5223 R&D Projects: GA ČR(CZ) GAP506/12/2472; GA MŠk EE2.3.20.0303 Institutional support: RVO:68081766 Keywords : gram-negative bacteria * barn swallow nestlings * white proteins * embryonic development * divergent selection * albumin removal * japanese-quail * avian egg * antimicrobial proteins * antibacterial activity Subject RIV: EG - Zoology Impact factor: 1.226, year: 2015

  5. Human Pol ζ purified with accessory subunits is active in translesion DNA synthesis and complements Pol η in cisplatin bypass.

    Science.gov (United States)

    Lee, Young-Sam; Gregory, Mark T; Yang, Wei

    2014-02-25

    DNA polymerase ζ (Pol ζ) is a eukaryotic B-family DNA polymerase that specializes in translesion synthesis and is essential for normal embryogenesis. At a minimum, Pol ζ consists of a catalytic subunit Rev3 and an accessory subunit Rev7. Mammalian Rev3 contains >3,000 residues and is twice as large as the yeast homolog. To date, no vertebrate Pol ζ has been purified for biochemical characterization. Here we report purification of a series of human Rev3 deletion constructs expressed in HEK293 cells and identification of a minimally catalytically active human Pol ζ variant. With a tagged form of an active Pol ζ variant, we isolated two additional accessory subunits of human Pol ζ, PolD2 and PolD3. The purified four-subunit Pol ζ4 (Rev3-Rev7-PolD2-PolD3) is much more efficient and more processive at bypassing a 1,2-intrastrand d(GpG)-cisplatin cross-link than the two-subunit Pol ζ2 (Rev3-Rev7). We show that complete bypass of cisplatin lesions requires Pol η to insert dCTP opposite the 3' guanine and Pol ζ4 to extend the primers.

  6. Controlling the complement system in inflammation.

    Science.gov (United States)

    Kirschfink, M

    1997-12-01

    Inappropriate or excessive activation of the complement system can lead to harmful, potentially life-threatening consequences due to severe inflammatory tissue destruction. These consequences are clinically manifested in various disorders, including septic shock, multiple organ failure and hyperacute graft rejection. Genetic complement deficiencies or complement depletion have been proven to be beneficial in reducing tissue injury in a number of animal models of severe complement-dependent inflammation. It is therefore believed that therapeutic inhibition of complement is likely to arrest the process of certain diseases. Attempts to efficiently inhibit complement include the application of endogenous soluble complement inhibitors (C1-inhibitor, recombinant soluble complement receptor 1- rsCR1), the administration of antibodies, either blocking key proteins of the cascade reaction (e.g. C3, C5), neutralizing the action of the complement-derived anaphylatoxin C5a, or interfering with complement receptor 3 (CR3, CD18/11b)-mediated adhesion of inflammatory cells to the vascular endothelium. In addition, incorporation of membrane-bound complement regulators (DAF-CD55, MCP-CD46, CD59) has become possible by transfection of the correspondent cDNA into xenogeneic cells. Thereby, protection against complement-mediated inflammatory tissue damage could be achieved in various animal models of sepsis, myocardial as well as intestinal ischemia/reperfusion injury, adult respiratory distress syndrome, nephritis and graft rejection. Supported by results from first clinical trials, complement inhibition appears to be a suitable therapeutic approach to control inflammation. Current strategies to specifically inhibit complement in inflammation have been discussed at a recent meeting on the 'Immune Consequences of Trauma, Shock and Sepsis', held from March 4-8, 1997, in Munich, Germany. The Congress (chairman: E. Faist, Munich, Germany), which was held in close cooperation with various

  7. GLUCOCORTICOSTEROIDS' EFFECT UPON THE COMPLEMENT LEVEL

    Directory of Open Access Journals (Sweden)

    Voja Pavlovic

    2001-03-01

    Full Text Available The effect of high doses of cortisol upon the level of the overall complements'hemolytic activity and particular complements' components is studies. The experimentsinvolved guinea pigs of male sex of the body mass from 300 to 400 g, namelythose that have not been treated by anything so far. The doses of hydrocortisone(Hemofarm DD were also used for the experiment. The overall complements'activity was determined by testing the capabilities of a series of various solutions ofthe guinea pigs' serum to separate sheep erythrocytes that were made sensitive byrabbit anti-erythrocyte antibodies. The determination of the C1, C2, C3 and C4complements' components was done by the method of the quantitative diffusion ofthe radial type by using the Partigen blocks Behringwerke AG. The series comprised25 guinea pigs of male sex. The low cortisol level rapidly increase the overallhemolytic activity of the complements of the C1 est erase concentration. Along withthe cortisol dose increase the overall hemolytic complements' activity is dropping aswell as that of the C1, C2, C3 and C4 complements' components.

  8. Crosstalk between Complement and Toll-like Receptor Activation in Relation to Donor Brain Death and Renal Ischemia-Reperfusion Injury

    NARCIS (Netherlands)

    Damman, Jeffrey; Daha, Mohamed R.; van Son, Willem J.; Leuvenink, Henri G.; Ploeg, Rutger J.; Seelen, Marc A.

    Two central pathways of innate immunity, complement and Toll-like receptors (TLRs), play an important role in the pathogenesis of renal injury inherent to kidney transplantation. Recent findings indicate close crosstalk between complement and TLR signaling pathways. It is suggested that mitogen

  9. Depletion of the Third Complement Component Ameliorates Age-Dependent Oxidative Stress and Positively Modulates Autophagic Activity in Aged Retinas in a Mouse Model

    Directory of Open Access Journals (Sweden)

    Dorota Rogińska

    2017-01-01

    Full Text Available The aim of the study was to investigate the influence of complement component C3 global depletion on the biological structure and function of the aged retina. In vivo morphology (OCT, electrophysiological function (ERG, and the expression of selected oxidative stress-, apoptosis-, and autophagy-related proteins were assessed in retinas of 12-month-old C3-deficient and WT mice. Moreover, global gene expression in retinas was analyzed by RNA arrays. We found that the absence of active C3 was associated with (1 alleviation of the age-dependent decrease in retinal thickness and gradual deterioration of retinal bioelectrical function, (2 significantly higher levels of antioxidant enzymes (catalase and glutathione reductase and the antiapoptotic survivin and Mcl-1/Bak dimer, (3 lower expression of the cellular oxidative stress marker—4HNE—and decreased activity of proapoptotic caspase-3, (4 ameliorated retinal autophagic activity with localization of ubiquitinated protein conjugates commonly along the retinal pigment epithelium (RPE layer, and (5 significantly increased expression of several gene sets associated with maintenance of the physiological functions of the neural retina. Our findings shed light on mechanisms of age-related retinal alterations by identifying C3 as a potential therapeutic target for retinal aging.

  10. The complement inhibitor eculizumab in paroxysmal nocturnal hemoglobinuria.

    NARCIS (Netherlands)

    Hillmen, P.; Young, N.S.; Schubert, J.; Brodsky, R.A.; Socie, G.; Muus, P.; Roth, A.; Szer, J.; Elebute, M.O.; Nakamura, R.; Browne, P.; Risitano, A.M.; Hill, A.; Schrezenmeier, H.; Fu, C.L.; Maciejewski, J; Rollins, S.A.; Mojcik, C.F.; Rother, R.P.; Luzzatto, L.

    2006-01-01

    BACKGROUND: We tested the safety and efficacy of eculizumab, a humanized monoclonal antibody against terminal complement protein C5 that inhibits terminal complement activation, in patients with paroxysmal nocturnal hemoglobinuria (PNH). METHODS: We conducted a double-blind, randomized,

  11. Surface-bound capsular polysaccharide of type Ia group B Streptococcus mediates C1 binding and activation of the classic complement pathway

    International Nuclear Information System (INIS)

    Levy, N.J.; Kasper, D.L.

    1986-01-01

    The role of surface-bound type Ia group B Streptococcus (GBS) capsular polysaccharide in anti-body-independent binding of C1 and activation of the classic component pathway was investigated. In a radiolabeled bacterial-polymorphonuclear leukocyte (PMN) association assay, a measure of bacterial opsonization, preincubation of 3 H-type Ia GBS with purified F(ab') 2 to the organism blocked the association of the bacteria with PMN', and the inhibitory effect was dose dependent. The specificity of F(ab') 2 blocking was shown after adsorption of F(ab') 2 with type Ia polysaccharide-sensitized erythrocytes. Polysaccharide-adsorbed F(ab') 2 had a 70% decrease in ability to block the association of bacteria with PMN. Neuraminidase digestion removed 80% of the terminal sialic acid residues from the native polysaccharide. These neuraminidase-digested organisms had a 72% decrease in binding and transfer of purified C1 compared with non-enzyme-treated organisms. Type Ia capsular polysaccharide bound to sheep erythrocytes promoted classic complement pathway-mediated hemolysis of the cells. The role of C1 inhibitor (INH) in modulation of C1 activation by the organisms was investigated. The possibility existed that the C1 INH could be bound by the bacteria, allowing C1 activation to occur in the fluid phase. The inhibitor was purified from human serum, and its activity was measured before and after incubation with type Ia GBS. The organisms had no effect on C1 INH activity. Thus surface-bound capsular polysacchardie of type Ia GBS mediates C1 binding and classic pathway activation, and this does not involve the C1 INH

  12. Experiences of nursing professionals in alternative and complementing therapies applied to people in pain situations Experiencias de profesionales de enfermería en terapias alternativas y complementarias aplicadas a personas en situaciones de dolor

    Directory of Open Access Journals (Sweden)

    MARÍN ARIZA DIEGO ANDRÉS

    2008-07-01

    Full Text Available To know the experiences of nursing professionals on the use of alternative and complementing therapies applied during health care to people in pain situations, a qualitative study was carried out, as a graduation project for a group of nursing students –undergraduates– from the Universidad del Bosque, between 2005 and 2007, in which four nursing professionals took part. They had several years of experience in the use of floral therapy, acupuncture, homeopathy, chiropractic massage therapy and naturopathy; in other words, those therapies that also enable a synergic action when combined with the conventional therapeutic medical-pharmacologic-surgical procedures, which they complement; the selection of participants wasmadeusing the "snow ball" technique. The information was gathered by means of semi-structured deep interviews. The analysis of the results enabled us to learn that said experiences do not have as sole purpose to relieve a determined type of pain, but, generally, to evaluate the health condition and to intervene with an integral focus, considering the individual as a holistic human being; on the other hand, this work has given the students great satisfaction and possibilities for personal development.Para conocer las experiencias de profesionales de enfermería en el uso de terapias alternativas y complementarias aplicadas durante el cuidado de la salud a personas en situación de dolor, se realizó un estudio cualitativo, como trabajo de grado de un grupo de estudiantes –de pregrado– de Enfermería de la Uni-versidad El Bosque, entre los años 2005 y 2007, en el que participaron cuatro profesionales de enfermería, con varios años de experiencia en la utilización de Terapia Floral, Acupuntura, Homeopatía, Quiromasaje y Naturopatía; es decir, aquellas terapias que, además permiten una acción sinérgica al combinarse con los procedimientos terapéuticos médico-farmacológicos-quirúrgicos convencionales, a los cuales

  13. Antiglycopeptide Mouse Monoclonal Antibody LpMab-21 Exerts Antitumor Activity Against Human Podoplanin Through Antibody-Dependent Cellular Cytotoxicity and Complement-Dependent Cytotoxicity.

    Science.gov (United States)

    Kato, Yukinari; Kunita, Akiko; Fukayama, Masashi; Abe, Shinji; Nishioka, Yasuhiko; Uchida, Hiroaki; Tahara, Hideaki; Yamada, Shinji; Yanaka, Miyuki; Nakamura, Takuro; Saidoh, Noriko; Yoshida, Kanae; Fujii, Yuki; Honma, Ryusuke; Takagi, Michiaki; Ogasawara, Satoshi; Murata, Takeshi; Kaneko, Mika K

    2017-02-01

    The interaction between podoplanin (PDPN) and C-type lectin-like receptor 2 (CLEC-2) is involved in tumor malignancy. We have established many monoclonal antibodies (mAbs) against human podoplanin using the cancer-specific mAb (CasMab) technology. LpMab-21, one of the mouse antipodoplanin mAbs, is of the IgG 2a subclass, and its minimum epitope was determined to be Thr76-Arg79 of the human podoplanin. Importantly, sialic acid is linked to Thr76; therefore, LpMab-21 is an antiglycopeptide mAb (GpMab). In this study, we investigated whether LpMab-21 shows antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against human podoplanin-expressing cancer cell lines in vitro and also studied its antitumor activities using a xenograft model. LpMab-21 showed high ADCC and CDC activities against not only podoplanin-expressing Chinese hamster ovary cells but also LN319 glioblastoma cells and PC-10 lung cancer cells, both of which endogenously express podoplanin. Furthermore, LpMab-21 decreased tumor growth in vivo, indicating that LpMab-21 could be useful for antibody therapy against human podoplanin-expressing cancers.

  14. Complement and thrombosis in the antiphospholipid syndrome.

    Science.gov (United States)

    Oku, Kenji; Nakamura, Hiroyuki; Kono, Michihiro; Ohmura, Kazumasa; Kato, Masaru; Bohgaki, Toshiyuki; Horita, Tetsuya; Yasuda, Shinsuke; Amengual, Olga; Atsumi, Tatsuya

    2016-10-01

    The involvement of complement activation in the pathophysiology of antiphospholipid syndrome (APS) was first reported in murine models of antiphospholipid antibody (aPL)-related pregnancy morbidities. We previously reported that complement activation is prevalent and may function as a source of procoagulant cell activation in the sera of APS patients. Recently, autoantibodies against C1q, a component of complement 1, were reported to be correlated with complement activation in systemic lupus erythematosus. These antibodies target neoepitopes of deformed C1q bound to various molecules (i.e., anionic phospholipids) and induce accelerated complement activation. We found that anti-C1q antibodies are more frequently detected in primary APS patients than in control patients and in refractory APS patients with repeated thrombotic events. The titer of anti-C1q antibodies was significantly higher in refractory APS patients than in APS patients without flare. The binding of C1q to anionic phospholipids may be associated with the surge in complement activation in patients with anti-C1q antibodies when triggered by 'second-hit' biological stressors such as infection. Such stressors will induce overexpression of anionic phospholipids, with subsequent increases in deformed C1q that is targeted by anti-C1q antibodies. Copyright © 2016. Published by Elsevier B.V.

  15. Complement C5a-C5aR interaction enhances MAPK signaling pathway activities to mediate renal injury in trichloroethylene sensitized BALB/c mice.

    Science.gov (United States)

    Zhang, Jia-xiang; Zha, Wan-sheng; Ye, Liang-ping; Wang, Feng; Wang, Hui; Shen, Tong; Wu, Chang-hao; Zhu, Qi-xing

    2016-02-01

    We have previously shown complement activation as a possible mechanism for trichloroethylene (TCE) sensitization, leading to multi-organ damage including the kidneys. In particular, excessive deposition of C5 and C5b-9-the membrane attack complex, which can generate significant tissue damage, was observed in the kidney tissue after TCE sensitization. The present study tested the hypothesis that anaphylatoxin C5a binding to its receptor C5aR mediates renal injury in TCE-sensitized BALB/c mice. BALB/c mice were sensitized through skin challenge with TCE, with or without pretreatment by the C5aR antagonist W54011. Kidney histopathology and the renal functional test were performed to assess renal injury, and immunohistochemistry and fluorescent labeling were carried out to assess C5a and C5aR expressions. TCE sensitization up-regulated C5a and C5aR expressions in kidney tissue, generated inflammatory infiltration, renal tubule damage, glomerular hypercellularity and impaired renal function. Antagonist pretreatment blocked C5a binding to C5aR and attenuated TCE-induced tissue damage and renal dysfunction. TCE sensitization also caused the deposition of major pro-inflammatory cytokines IL-2, TNF-α and IFN-γ in the kidney tissue (P < 0.05); this was accompanied by increased expression of P-p38, P-ERK and P-JNK proteins (P < 0.05). Pretreatment with the C5aR antagonist attenuated the increase of expression of P-p38, P-ERK and P-JNK proteins (P < 0.05) and also consistently reduced the TCE sensitization-induced increase of IL-2, TNF-α and IFN-γ (P < 0.05). These data identify C5a binding to C5aR, MAP kinase activation, and inflammatory cytokine release as a novel mechanism for complement-mediated renal injury by sensitization with TCE or other environmental chemicals. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Evasion Mechanisms Used by Pathogens to Escape the Lectin Complement Pathway.

    Science.gov (United States)

    Rosbjerg, Anne; Genster, Ninette; Pilely, Katrine; Garred, Peter

    2017-01-01

    The complement system is a crucial defensive network that protects the host against invading pathogens. It is part of the innate immune system and can be initiated via three pathways: the lectin, classical and alternative activation pathway. Overall the network compiles a group of recognition molecules that bind specific patterns on microbial surfaces, a group of associated proteases that initiates the complement cascade, and a group of proteins that interact in proteolytic complexes or the terminal pore-forming complex. In addition, various regulatory proteins are important for controlling the level of activity. The result is a pro-inflammatory response meant to combat foreign microbes. Microbial elimination is, however, not a straight forward procedure; pathogens have adapted to their environment by evolving a collection of evasion mechanisms that circumvent the human complement system. Complement evasion strategies features different ways of exploiting human complement proteins and moreover features different pathogen-derived proteins that interfere with the normal processes. Accumulated, these mechanisms target all three complement activation pathways as well as the final common part of the cascade. This review will cover the currently known lectin pathway evasion mechanisms and give examples of pathogens that operate these to increase their chance of invasion, survival and dissemination.

  17. Complement System Part II: Role in Immunity

    Science.gov (United States)

    Merle, Nicolas S.; Noe, Remi; Halbwachs-Mecarelli, Lise; Fremeaux-Bacchi, Veronique; Roumenina, Lubka T.

    2015-01-01

    The complement system has been considered for a long time as a simple lytic cascade, aimed to kill bacteria infecting the host organism. Nowadays, this vision has changed and it is well accepted that complement is a complex innate immune surveillance system, playing a key role in host homeostasis, inflammation, and in the defense against pathogens. This review discusses recent advances in the understanding of the role of complement in physiology and pathology. It starts with a description of complement contribution to the normal physiology (homeostasis) of a healthy organism, including the silent clearance of apoptotic cells and maintenance of cell survival. In pathology, complement can be a friend or a foe. It acts as a friend in the defense against pathogens, by inducing opsonization and a direct killing by C5b–9 membrane attack complex and by triggering inflammatory responses with the anaphylatoxins C3a and C5a. Opsonization plays also a major role in the mounting of an adaptive immune response, involving antigen presenting cells, T-, and B-lymphocytes. Nevertheless, it can be also an enemy, when pathogens hijack complement regulators to protect themselves from the immune system. Inadequate complement activation becomes a disease cause, as in atypical hemolytic uremic syndrome, C3 glomerulopathies, and systemic lupus erythematosus. Age-related macular degeneration and cancer will be described as examples showing that complement contributes to a large variety of conditions, far exceeding the classical examples of diseases associated with complement deficiencies. Finally, we discuss complement as a therapeutic target. PMID:26074922

  18. Mesenchymal stromal cells engage complement and complement receptor bearing innate effector cells to modulate immune responses.

    Directory of Open Access Journals (Sweden)

    Guido Moll

    Full Text Available Infusion of human third-party mesenchymal stromal cells (MSCs appears to be a promising therapy for acute graft-versus-host disease (aGvHD. To date, little is known about how MSCs interact with the body's innate immune system after clinical infusion. This study shows, that exposure of MSCs to blood type ABO-matched human blood activates the complement system, which triggers complement-mediated lymphoid and myeloid effector cell activation in blood. We found deposition of complement component C3-derived fragments iC3b and C3dg on MSCs and fluid-phase generation of the chemotactic anaphylatoxins C3a and C5a. MSCs bound low amounts of immunoglobulins and lacked expression of complement regulatory proteins MCP (CD46 and DAF (CD55, but were protected from complement lysis via expression of protectin (CD59. Cell-surface-opsonization and anaphylatoxin-formation triggered complement receptor 3 (CD11b/CD18-mediated effector cell activation in blood. The complement-activating properties of individual MSCs were furthermore correlated with their potency to inhibit PBMC-proliferation in vitro, and both effector cell activation and the immunosuppressive effect could be blocked either by using complement inhibitor Compstatin or by depletion of CD14/CD11b-high myeloid effector cells from mixed lymphocyte reactions. Our study demonstrates for the first time a major role of the complement system in governing the immunomodulatory activity of MSCs and elucidates how complement activation mediates the interaction with other immune cells.

  19. Lattices with unique complements

    CERN Document Server

    Saliĭ, V N

    1988-01-01

    The class of uniquely complemented lattices properly contains all Boolean lattices. However, no explicit example of a non-Boolean lattice of this class has been found. In addition, the question of whether this class contains any complete non-Boolean lattices remains unanswered. This book focuses on these classical problems of lattice theory and the various attempts to solve them. Requiring no specialized knowledge, the book is directed at researchers and students interested in general algebra and mathematical logic.

  20. A revised mechanism for the activation of complement C3 to C3b: a molecular explanation of a disease-associated polymorphism.

    Science.gov (United States)

    Rodriguez, Elizabeth; Nan, Ruodan; Li, Keying; Gor, Jayesh; Perkins, Stephen J

    2015-01-23

    The solution structure of complement C3b is crucial for the understanding of complement activation and regulation. C3b is generated by the removal of C3a from C3. Hydrolysis of the C3 thioester produces C3u, an analog of C3b. C3b cleavage results in C3c and C3d (thioester-containing domain; TED). To resolve functional questions in relation to C3b and C3u, analytical ultracentrifugation and x-ray and neutron scattering studies were used with C3, C3b, C3u, C3c, and C3d, using the wild-type allotype with Arg(102). In 50 mm NaCl buffer, atomistic scattering modeling showed that both C3b and C3u adopted a compact structure, similar to the C3b crystal structure in which its TED and macroglobulin 1 (MG1) domains were connected through the Arg(102)-Glu(1032) salt bridge. In physiological 137 mm NaCl, scattering modeling showed that C3b and C3u were both extended in structure, with the TED and MG1 domains now separated by up to 6 nm. The importance of the Arg(102)-Glu(1032) salt bridge was determined using surface plasmon resonance to monitor the binding of wild-type C3d(E1032) and mutant C3d(A1032) to immobilized C3c. The mutant did not bind, whereas the wild-type form did. The high conformational variability of TED in C3b in physiological buffer showed that C3b is more reactive than previously thought. Because the Arg(102)-Glu(1032) salt bridge is essential for the C3b-Factor H complex during the regulatory control of C3b, the known clinical associations of the major C3S (Arg(102)) and disease-linked C3F (Gly(102)) allotypes of C3b were experimentally explained for the first time. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Autocrine Effects of Tumor-Derived Complement

    Directory of Open Access Journals (Sweden)

    Min Soon Cho

    2014-03-01

    Full Text Available We describe a role for the complement system in enhancing cancer growth. Cancer cells secrete complement proteins that stimulate tumor growth upon activation. Complement promotes tumor growth via a direct autocrine effect that is partially independent of tumor-infiltrating cytotoxic T cells. Activated C5aR and C3aR signal through the PI3K/AKT pathway in cancer cells, and silencing the PI3K or AKT gene in cancer cells eliminates the progrowth effects of C5aR and C3aR stimulation. In patients with ovarian or lung cancer, higher tumoral C3 or C5aR mRNA levels were associated with decreased overall survival. These data identify a role for tumor-derived complement proteins in promoting tumor growth, and they therefore have substantial clinical and therapeutic implications.

  2. Human pentraxin 3 binds to the complement regulator c4b-binding protein.

    Directory of Open Access Journals (Sweden)

    Anne Braunschweig

    Full Text Available The long pentraxin 3 (PTX3 is a soluble recognition molecule with multiple functions including innate immune defense against certain microbes and the clearance of apoptotic cells. PTX3 interacts with recognition molecules of the classical and lectin complement pathways and thus initiates complement activation. In addition, binding of PTX3 to the alternative complement pathway regulator factor H was shown. Here, we show that PTX3 binds to the classical and lectin pathway regulator C4b-binding protein (C4BP. A PTX3-binding site was identified within short consensus repeats 1-3 of the C4BP α-chain. PTX3 did not interfere with the cofactor activity of C4BP in the fluid phase and C4BP maintained its complement regulatory activity when bound to PTX3 on surfaces. While C4BP and factor H did not compete for PTX3 binding, the interaction of C4BP with PTX3 was inhibited by C1q and by L-ficolin. PTX3 bound to human fibroblast- and endothelial cell-derived extracellular matrices and recruited functionally active C4BP to these surfaces. Whereas PTX3 enhanced the activation of the classical/lectin pathway and caused enhanced C3 deposition on extracellular matrix, deposition of terminal pathway components and the generation of the inflammatory mediator C5a were not increased. Furthermore, PTX3 enhanced the binding of C4BP to late apoptotic cells, which resulted in an increased rate of inactivation of cell surface bound C4b and a reduction in the deposition of C5b-9. Thus, in addition to complement activators, PTX3 interacts with complement inhibitors including C4BP. This balanced interaction on extracellular matrix and on apoptotic cells may prevent excessive local complement activation that would otherwise lead to inflammation and host tissue damage.

  3. Activities of electric utilities in alternative energy projects

    International Nuclear Information System (INIS)

    Silva, D.B. da; Reis Neto, J.L. dos

    1990-01-01

    Since oil crisis, in 1973 and 1979, some electrical utilities in Brazil begun investments in alternative projects for example production of electrolytic hydrogen, peats with energetics goals, steam from electric boiler, and methanol from wood gasification. With oil substitution goals, these projects have not success actually, after attenuated the crisis. However, the results acquired is experience for the development of the brazilian energy patterns. (author)

  4. Site-targeted complement inhibition by a complement receptor 2-conjugated inhibitor (mTT30) ameliorates post-injury neuropathology in mouse brains.

    Science.gov (United States)

    Rich, Megan C; Keene, Chesleigh N; Neher, Miriam D; Johnson, Krista; Yu, Zhao-Xue; Ganivet, Antoine; Holers, V Michael; Stahel, Philip F

    2016-03-23

    Intracerebral complement activation after severe traumatic brain injury (TBI) leads to a cascade of neuroinflammatory pathological sequelae that propagate host-mediated secondary brain injury and adverse outcomes. There are currently no specific pharmacological agents on the market to prevent or mitigate the development of secondary cerebral insults after TBI. A novel chimeric CR2-fH compound (mTT30) provides targeted inhibition of the alternative complement pathway at the site of tissue injury. This experimental study was designed to test the neuroprotective effects of mTT30 in a mouse model of closed head injury. The administration of 500 μg mTT30 i.v. at 1 h, 4 h and 24 h after head injury attenuated complement C3 deposition in injured brains, reduced the extent of neuronal cell death, and decreased post-injury microglial activation, compared to vehicle-injected placebo controls. These data imply that site-targeted alternative pathway complement inhibition may represent a new promising therapeutic avenue for the future management of severe TBI. Copyright © 2016. Published by Elsevier Ireland Ltd.

  5. Redefining the transcriptional regulatory dynamics of classically and alternatively activated macrophages by deepCAGE transcriptomics

    KAUST Repository

    Roy, S.; Schmeier, S.; Arner, E.; Alam, Tanvir; Parihar, S. P.; Ozturk, M.; Tamgue, O.; Kawaji, H.; de Hoon, M. J. L.; Itoh, M.; Lassmann, T.; Carninci, P.; Hayashizaki, Y.; Forrest, A. R. R.; Bajic, Vladimir B.; Guler, R.; Consortium, F.; Brombacher, F.; Suzuki, H.

    2015-01-01

    Classically or alternatively activated macrophages (M1 and M2, respectively) play distinct and important roles for microbiocidal activity, regulation of inflammation and tissue homeostasis. Despite this, their transcriptional regulatory dynamics

  6. Complementary Roles of the Classical and Lectin Complement Pathways in the Defense against Aspergillus fumigatus

    DEFF Research Database (Denmark)

    Rosbjerg, Anne; Genster, Ninette; Pilely, Katrine

    2016-01-01

    Aspergillus fumigatus infections are associated with a high mortality rate for immunocompromised patients. The complement system is considered to be important in protection against this fungus, yet the course of activation is unclear. The aim of this study was to unravel the role of the classical......, lectin, and alternative pathways under both immunocompetent and immunocompromised conditions to provide a relevant dual-perspective on the response against A. fumigatus. Conidia (spores) from a clinical isolate of A. fumigatus were combined with various human serum types (including serum deficient...... complement on A. fumigatus, but required classical and/or lectin pathway for initiation. In normal human serum, this initiation came primarily from the classical pathway. However, with a dysfunctional classical pathway (C1q-deficient serum), lectin pathway activated complement and mediated opsonophagocytosis...

  7. Heterocomplexes of mannose-binding lectin and the pentraxins PTX3 or SAP trigger cross-activation of the complement system

    DEFF Research Database (Denmark)

    Ma, Ying Jie; Doni, Andrea; Skjødt, Mikkel-Ole

    2011-01-01

    The long pentraxin 3 (PTX3), serum amyloid P component (SAP) and C-reactive protein (CRP) belong to the pentraxin family of pattern recognition molecules involved in tissue homeostasis and innate immunity. They interact with C1q from the classical complement pathway. Whether this also occurs via...... the analogous mannose-binding lectin (MBL) from the lectin complement pathway is unknown. Thus, we investigated the possible interaction between MBL and the pentraxins. We report that MBL bound PTX3 and SAP partly via its collagen-like domain, but not CRP. MBL:PTX3 complex formation resulted in recruitment of C......1q, but this was not seen for the MBL:SAP complex. However, both MBL:PTX3 and MBL:SAP complexes enhanced C4 and C3 deposition and opsonophagocytosis of Candida albicans by polymorphonuclear leukocytes. Interaction between MBL and PTX3 lead to communication between the lectin and classical complement...

  8. Changing University Students' Alternative Conceptions of Optics by Active Learning

    Science.gov (United States)

    Hadžibegovic, Zalkida; Sliško, Josip

    2013-01-01

    Active learning is individual and group participation in effective activities such as in-class observing, writing, experimenting, discussion, solving problems, and talking about to-be-learned topics. Some instructors believe that active learning is impossible, or at least extremely difficult to achieve in large lecture sessions. Nevertheless, the…

  9. complement C3, Complement C4 and C-reactive protein

    African Journals Online (AJOL)

    ajl yemi

    2011-12-19

    Dec 19, 2011 ... (IL-6), E-selectin and P-selectin (Perlstein and Lee,. 2006). Studies have ... of cigarette smoke causes complement activation which is in turn ..... are decreased by long term smoking cessation in male smokers. Prevent. Med.

  10. Human IgG is produced in a pro-form that requires clipping of C-terminal lysines for maximal complement activation

    DEFF Research Database (Denmark)

    van den Bremer, E. T. J.; Beurskens, F. J.; Voorhorst, M.

    2015-01-01

    Human IgG is produced with C-terminal lysines that are cleaved off in circulation. The function of this modification was unknown and generally thought not to affect antibody function. We recently reported that efficient C1q binding and complement-dependent cytotoxicity (CDC) requires IgG hexameri...

  11. Antibody-dependent NK cell activation is associated with late kidney allograft dysfunction and the complement-independent alloreactive potential of donor-specific antibodies

    Directory of Open Access Journals (Sweden)

    Tristan Legris

    2016-08-01

    Full Text Available Although kidney transplantation remains the best treatment for end-stage renal failure, it is limited by chronic humoral aggression of the graft vasculature by donor-specific antibodies (DSAs. The complement-independent mechanisms that lead to the antibody-mediated rejection (ABMR of kidney allografts remain poorly understood. Increasing lines of evidence have revealed the relevance of natural killer (NK cells as innate immune effectors of antibody-dependent cellular cytotoxicity, but few studies have investigated their alloreactive potential in the context of solid organ transplantation. Our study aimed to investigate the potential contribution of the antibody-dependent alloreactive function of NK cells to kidney graft dysfunction. We first conducted an observational study to investigate whether the cytotoxic function of NK cells is associated with chronic allograft dysfunction. The NK-Cellular Humoral Activation Test (NK-CHAT was designed to evaluate the recipient and antibody-dependent reactivity of NK cells against allogeneic target cells. The release of CD107a/Lamp1+ cytotoxic granules, resulting from the recognition of rituximab-coated B cells by NK cells, was analyzed in 148 kidney transplant recipients (KTRs, mean graft duration: 6.2 years. Enhanced ADCC responsiveness was associated with reduced graft function and identified as an independent risk factor predicting a decline in the estimated glomerular filtration rate (eGFR over a 1-year period (hazard ratio: 2.83. In a second approach, we used the NK-CHAT to reveal the cytotoxic potential of circulating alloantibodies in vitro. The level of CD16 engagement resulting from the in vitro recognition of serum-coated allogeneic B cells or splenic cells was further identified as a specific marker of DSA-induced ADCC. The NK-CHAT scoring of sera obtained from 40 patients at the time of transplant biopsy was associated with ABMR diagnosis. Our findings indicate that despite the administration

  12. Hijacking Complement Regulatory Proteins for Bacterial Immune Evasion.

    Science.gov (United States)

    Hovingh, Elise S; van den Broek, Bryan; Jongerius, Ilse

    2016-01-01

    The human complement system plays an important role in the defense against invading pathogens, inflammation and homeostasis. Invading microbes, such as bacteria, directly activate the complement system resulting in the formation of chemoattractants and in effective labeling of the bacteria for phagocytosis. In addition, formation of the membrane attack complex is responsible for direct killing of Gram-negative bacteria. In turn, bacteria have evolved several ways to evade complement activation on their surface in order to be able to colonize and invade the human host. One important mechanism of bacterial escape is attraction of complement regulatory proteins to the microbial surface. These molecules are present in the human body for tight regulation of the complement system to prevent damage to host self-surfaces. Therefore, recruitment of complement regulatory proteins to the bacterial surface results in decreased complement activation on the microbial surface which favors bacterial survival. This review will discuss recent advances in understanding the binding of complement regulatory proteins to the bacterial surface at the molecular level. This includes, new insights that have become available concerning specific conserved motives on complement regulatory proteins that are favorable for microbial binding. Finally, complement evasion molecules are of high importance for vaccine development due to their dominant role in bacterial survival, high immunogenicity and homology as well as their presence on the bacterial surface. Here, the use of complement evasion molecules for vaccine development will be discussed.

  13. Alternatives evaluation of high activity radioactive wastes disposal

    International Nuclear Information System (INIS)

    Ciallella, N.R.; Petraitis, E.J.

    1989-01-01

    Different alternatives considered in the world to be used as barriers to isolate the high level radioactive from the environment wastes produced during the electric energy generation of nuclear origin are presented. Engineering and geologic barriers, are analyzed, considering nuclear fuel cycles with or without plutonium recycling; to that purpose the consideration of elements such as durability and resistance of the various engineering, availability of the fabrication processes, associated radiological impact, geological media apt to be used as geological barrier. Finally, the scopes of the Feasibility Study and Engineering draft are presented for the construction of a repository for high-level radioactive wastes, for the Argentine Nuclear Program needs, which contemplates the construction of six nuclear power plants with a potential installed towards the year 2000 GW( e ), with natural and/or lowly enriched uranium power plants and recycling of plutonium generated in the cycle. (Author) [es

  14. Francisella tularensis Confronts the Complement System

    Directory of Open Access Journals (Sweden)

    Susan R. Brock

    2017-12-01

    Full Text Available Francisella tularensis has developed a number of effective evasion strategies to counteract host immune defenses, not the least of which is its ability to interact with the complement system to its own advantage. Following exposure of the bacterium to fresh human serum, complement is activated and C3b and iC3b can be found covalently attached to the bacterial surface. However, the lipopolysaccharide and capsule of the F. tularensis cell wall prevent complement-mediated lysis and endow the bacterium with serum resistance. Opsonization of F. tularensis with C3 greatly increases its uptake by human neutrophils, dendritic cells and macrophages. Uptake occurs by an unusual looping morphology in human macrophages. Complement receptor 3 is thought to play an important role in opsonophagocytosis by human macrophages, and signaling through this receptor can antagonize Toll-like receptor 2-initiated macrophage activation. Complement C3 also determines the survival of infected human macrophages and perhaps other cell types. C3-opsonization of F. tularensis subsp. tularensis strain SCHU S4 results in greatly increased death of infected human macrophages, which requires more than complement receptor engagement and is independent of the intracellular replication by the pathogen. Given its entry into the cytosol of host cells, F. tularensis has the potential for a number of other complement-mediated interactions. Studies on the uptake C3-opsonized adenovirus have suggested the existence of a C3 sensing system that initiates cellular responses to cytosolic C3b present on invading microbes. Here we propose that C3 peptides enter the cytosol of human macrophages following phagosome escape of F. tularensis and are recognized as intruding molecular patterns that signal host cell death. With the discovery of new roles for intracellular C3, a better understanding of tularemia pathogenesis is likely to emerge.

  15. SELENIUM TREATMENT/REMOVAL ALTERNATIVES DEMONSTRATION PROJECT - MINE WASTE TECHNOLOGY PROGRAM ACTIVITY III, PROJECT 20

    Science.gov (United States)

    This document is the final report for EPA's Mine WAste Technology Program (MWTP) Activity III, Project 20--Selenium Treatment/Removal Alternatives Demonstration project. Selenium contamination originates from many sources including mining operations, mineral processing, abandoned...

  16. Electrochemically activated water as an alternative to chlorine for decentralized disinfection

    KAUST Repository

    Ghebremichael, Kebreab A.; Muchelemba, E.; Petruševski, Branislav; Amy, Gary L.

    2011-01-01

    Electrochemically activated (ECA) water is being extensively studied and considered as an alternative to chlorine for disinfection. Some researchers claim that ECA is by and large a chlorine solution, while others claim the presence of reactive

  17. Complement, a target for therapy in inflammatory and degenerative diseases.

    Science.gov (United States)

    Morgan, B Paul; Harris, Claire L

    2015-12-01

    The complement system is a key innate immune defence against infection and an important driver of inflammation; however, these very properties can also cause harm. Inappropriate or uncontrolled activation of complement can cause local and/or systemic inflammation, tissue damage and disease. Complement provides numerous options for drug development as it is a proteolytic cascade that involves nine specific proteases, unique multimolecular activation and lytic complexes, an arsenal of natural inhibitors, and numerous receptors that bind to activation fragments. Drug design is facilitated by the increasingly detailed structural understanding of the molecules involved in the complement system. Only two anti-complement drugs are currently on the market, but many more are being developed for diseases that include infectious, inflammatory, degenerative, traumatic and neoplastic disorders. In this Review, we describe the history, current landscape and future directions for anti-complement therapies.

  18. Alternative method for quantification of alfa-amylase activity.

    Science.gov (United States)

    Farias, D F; Carvalho, A F U; Oliveira, C C; Sousa, N M; Rocha-Bezerrra, L C B; Ferreira, P M P; Lima, G P G; Hissa, D C

    2010-05-01

    A modification of the sensitive agar diffusion method was developed for macro-scale determination of alfa-amylase. The proposed modifications lower costs with the utilisation of starch as substrate and agar as supporting medium. Thus, a standard curve was built using alfa-amylase solution from Aspergillus oryzae, with concentrations ranging from 2.4 to 7,500 U.mL-1. Clear radial diffusion zones were measured after 4 hours of incubation at 20 A degrees C. A linear relationship between the logarithm of enzyme activities and the area of clear zones was obtained. The method was validated by testing alpha-amylase from barley at the concentrations of 2.4; 60; 300 and 1,500 U.mL-1. The proposed method turned out to be simpler, faster, less expensive and able to determine on a macro-scale alpha-amylase over a wide range (2.4 to 7,500 U.mL-1) in scientific investigation as well as in teaching laboratory activities.

  19. Alternative method for quantification of alfa-amylase activity

    Directory of Open Access Journals (Sweden)

    DF. Farias

    Full Text Available A modification of the sensitive agar diffusion method was developed for macro-scale determination of alfa-amylase. The proposed modifications lower costs with the utilisation of starch as substrate and agar as supporting medium. Thus, a standard curve was built using alfa-amylase solution from Aspergillus oryzae, with concentrations ranging from 2.4 to 7,500 U.mL-1. Clear radial diffusion zones were measured after 4 hours of incubation at 20 °C. A linear relationship between the logarithm of enzyme activities and the area of clear zones was obtained. The method was validated by testing α-amylase from barley at the concentrations of 2.4; 60; 300 and 1,500 U.mL-1. The proposed method turned out to be simpler, faster, less expensive and able to determine on a macro-scale α-amylase over a wide range (2.4 to 7,500 U.mL-1 in scientific investigation as well as in teaching laboratory activities.

  20. Urease Activity Represents an Alternative Pathway for Mycobacterium tuberculosis Nitrogen Metabolism

    Science.gov (United States)

    Lin, Wenwei; Mathys, Vanessa; Ang, Emily Lei Yin; Koh, Vanessa Hui Qi; Martínez Gómez, Julia María; Ang, Michelle Lay Teng; Zainul Rahim, Siti Zarina; Tan, Mai Ping; Pethe, Kevin

    2012-01-01

    Urease represents a critical virulence factor for some bacterial species through its alkalizing effect, which helps neutralize the acidic microenvironment of the pathogen. In addition, urease serves as a nitrogen source provider for bacterial growth. Pathogenic mycobacteria express a functional urease, but its role during infection has yet to be characterized. In this study, we constructed a urease-deficient Mycobacterium tuberculosis strain and confirmed the alkalizing effect of the urease activity within the mycobacterium-containing vacuole in resting macrophages but not in the more acidic phagolysosomal compartment of activated macrophages. However, the urease-mediated alkalizing effect did not confer any growth advantage on M. tuberculosis in macrophages, as evidenced by comparable growth profiles for the mutant, wild-type (WT), and complemented strains. In contrast, the urease-deficient mutant exhibited impaired in vitro growth compared to the WT and complemented strains when urea was the sole source of nitrogen. Substantial amounts of ammonia were produced by the WT and complemented strains, but not with the urease-deficient mutant, which represents the actual nitrogen source for mycobacterial growth. However, the urease-deficient mutant displayed parental colonization profiles in the lungs, spleen, and liver in mice. Together, our data demonstrate a role for the urease activity in M. tuberculosis nitrogen metabolism that could be crucial for the pathogen's survival in nutrient-limited microenvironments where urea is the sole nitrogen source. Our work supports the notion that M. tuberculosis virulence correlates with its unique metabolic versatility and ability to utilize virtually any carbon and nitrogen sources available in its environment. PMID:22645285

  1. Complement propriety and conspiracy in nanomedicine

    DEFF Research Database (Denmark)

    Moghimi, Seyed Moein

    2016-01-01

    The complement system is the first line of body's defense against intruders and it acts as a functional bridge between innate and adaptive arms of the immune system. This commentary examines the key roles of complement activation in response to nanomedicine administration, including nucleic acid...... complexes. These comprise beneficial (eg, adjuvanticity) as well as adverse effects (eg, infusion-related reactions). Pigs (and sheep) are often used as predictive models of nanomedicine-mediated infusion-related reactions in humans. The validity of these models in relation to human responses is questioned...

  2. Brain activity during bilateral rapid alternate finger tapping measured with magnetoencephalography

    Science.gov (United States)

    Fukuda, Hiroshi; Odagaki, Masato; Hiwaki, Osamu; Kodabashi, Atsushi; Fujimoto, Toshiro

    2009-04-01

    Using magnetoencephalography (MEG), brain regions involved in an alternate bimanual tapping task by index fingers triggered with spontaneous timing were investigated. The tapping mode in which both index fingers moved simultaneously was interlaced during the task. The groups of the alternate tapping (AL mode) and the simultaneous tapping (SI mode) were extracted from the successive alternating taps with a histogram of intervals between the right and left index fingers. MEG signals in each mode were averaged separately before and after the tapping initiation of the dominant index finger. The activities of the contralateral sensorimotor cortex before and after the tapping initiation in the AL mode were larger than that in the SI mode. The result indicates that the activity of the contralateral sensorimotor cortex depends on the degree of achievement in the difficult motor task such as the voluntary alternate tapping movements.

  3. Inhibition of the classical pathway of the complement system by saliva of Amblyomma cajennense (Acari: Ixodidae).

    Science.gov (United States)

    Franco, Paula F; Silva, Naylene C S; Fazito do Vale, Vladimir; Abreu, Jéssica F; Santos, Vânia C; Gontijo, Nelder F; Valenzuela, Jesus G; Pereira, Marcos H; Sant'Anna, Mauricio R V; Gomes, Alessandra P S; Araujo, Ricardo N

    2016-05-01

    Inhibition of the complement system during and after haematophagy is of utmost importance for tick success in feeding and tick development. The role of such inhibition is to minimise damage to the intestinal epithelium as well as avoiding inflammation and opsonisation of salivary molecules at the bite site. Despite its importance, the salivary anti-complement activity has been characterised only in species belonging to the Ixodes ricinus complex which saliva is able to inhibit the alternative and lectin pathways. Little is known about this activity in other species of the Ixodidae family. Thus, the aim of this study was to describe the inhibition of the classical pathway of the complement system by the saliva of Amblyomma cajennense at different stages of the haematophagy. The A. cajennense saliva and salivary gland extract (SGE) were able to inhibit the complement classical pathway through haemolytic assays with higher activity observed when saliva was used. The anti-complement activity is present in the salivary glands of starving females and also in females throughout the whole feeding process, with significant higher activity soon after tick detachment. The SGE activity from both females fed on mice or horses had no significant correlation (p > 0.05) with tick body weight. The pH found in the intestinal lumen of A. cajennense was 8.04 ± 0.08 and haemolytic assays performed at pH 8.0 showed activation of the classical pathway similarly to what occurs at pH 7.4. Consequently, inhibition could be necessary to protect the tick enterocytes. Indeed, the inhibition observed by SGE was higher in pH 8.0 in comparison to pH 7.4 reinforcing the role of saliva in protecting the intestinal cells. Further studies should be carried out in order to identify the inhibitor molecule and characterise its inhibition mechanism. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Complement component 4

    Science.gov (United States)

    ... the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic ... with an autoimmune disorder . For example, people with active systemic lupus erythematosus may have lower-than-normal ...

  5. Complement-mediated solubilization of immune complexes and their interaction with complement C3 receptors

    DEFF Research Database (Denmark)

    Petersen, Ivan; Baatrup, Gunnar; Jepsen, H H

    1985-01-01

    Some of the molecular events in the complement (C)-mediated solubilization of immune complexes (IC) have been clarified in recent years. The solubilization is primarily mediated by alternative C pathway proteins whereas factors in the classical pathway accelerate the process. Components of the me......Some of the molecular events in the complement (C)-mediated solubilization of immune complexes (IC) have been clarified in recent years. The solubilization is primarily mediated by alternative C pathway proteins whereas factors in the classical pathway accelerate the process. Components...... of the cellular localization, expression and structure of the C3 receptors, especially the C3b (CR1) receptor, has been considerably extended in the last few years, whereas our understanding of the physiological role of these receptors is still fragmentary. However, it is becoming increasingly evident...

  6. Complementing the sugar code: role of GAGs and sialic acid in complement regulation

    Directory of Open Access Journals (Sweden)

    Alex eLangford-Smith

    2015-02-01

    Full Text Available Sugar molecules play a vital role on both microbial and mammalian cells, where they are involved in cellular communication, govern microbial virulence and modulate host immunity and inflammatory responses. The complement cascade, as part of a host’s innate immune system, is a potent weapon against invading bacteria but has to be tightly regulated to prevent inappropriate attack and damage to host tissues. A number of complement regulators, such as factor H and properdin, interact with sugar molecules, such as glycosaminoglycans and sialic acid, on host and pathogen membranes and direct the appropriate complement response by either promoting the binding of complement activators or inhibitors. The binding of these complement regulators to sugar molecules can vary from location to location, due to their different specificities and because distinct structural and functional subpopulations of sugars are found in different human organs, such as the brain, kidney and eye. This review will cover recent studies that have provided important new insights into the role of glycosaminoglycans and sialic acid in complement regulation and how sugar recognition may be compromised in disease

  7. Immune complex modulation by plasma proteins. With special reference to the complement system and autoimmune diseases

    DEFF Research Database (Denmark)

    Baatrup, G

    1989-01-01

    The complement (C) system consists of two activation pathways, the classical and the alternative, which may both be activated by immune complexes (IC). C activation products become attached to the IC during activation leading to profound changes in the properties of the complexes. The common...... inflammation. 5) Tissue damage by activation and/or lysis of bystanding cells. 6) Modulation of B-cell proliferation and differentiation. Activation of the C system by IC is an essential normal component in the clearance of invading foreign material. However, in conditions with a persistent high concentration...... preformed, fluid phase IC (CMS assay). The CMS was found to be dependent upon the alternative pathway of C and facilitated by the classical. Further studies concerning the influence of C deficiencies or depletion of C factors, the concentration of divalent metallions, the temperature and the ionic strength...

  8. Complement-mediated killing of Borrelia burgdorferi by nonimmune sera from sika deer.

    Science.gov (United States)

    Nelson, D R; Rooney, S; Miller, N J; Mather, T N

    2000-12-01

    Various species of cervid deer are the preferred hosts for adult, black-legged ticks (Ixodes scapularis and Ixodes pacificus) in the United States. Although frequently exposed to the agent of Lyme disease (Borrelia burgdorferi), these animals, for the most part, are incompetent as transmission reservoirs. We examined the borreliacidal activity of normal and B. burgdorferi-immune sera from sika deer (Cervus nippon) maintained in a laboratory setting and compared it to that of similar sera from reservoir-competent mice and rabbits. All normal deer sera (NDS) tested killed > 90% of B. burgdorferi cells. In contrast, normal mouse and rabbit sera killed feeding exhibited IFA titers of 1:256, whereas sera from mice and rabbits similarly exposed had titers of > 1:1,024. Heat treatment (56 C, 30 min) of NDS reduced borreliacidal activity, with complement-mediated killing. The chelators EGTA and EDTA were used to block the classical or both the classical and alternative complement pathways, respectively. Addition of 10 mM EGTA to NDS had a negligible effect on borreliacidal activity, with > 90% of the cells killed. Addition of 10 mM EDTA reduced the killing to approximately 30%, whereas the addition of Mg2+ (10 mM) restored borreliacidal activity to NDS. The addition of zymosan A, an activator of the alternative pathway, increased the survival of B. burgdorferi cells to approximately 80% in NDS. These data suggest that the alternative complement activation pathway plays a major role in the borreliacidal activity of NDS. Additionally, 10 mM EGTA had almost no effect on the killing activity of B. burgdorferi-exposed deer sera, suggesting that the classical pathway is not involved in Borrelia killing, even in sera from B. burgdorferi-exposed deer.

  9. A vital role for complement in heart disease

    DEFF Research Database (Denmark)

    Lappegård, Knut T; Garred, Peter; Jonasson, Lena

    2014-01-01

    fibrillation often share risk factors both with coronary heart disease and heart failure, and there is some evidence implicating complement activation in atrial fibrillation. Moreover, Chagas heart disease, a protozoal infection, is an important cause of heart failure in Latin America, and the complement...

  10. Evaluation of treatment alternatives for wastes from both spent fuel rod consolidation and miscellaneous commercial activities

    International Nuclear Information System (INIS)

    Ross, W.A.; Schneider, K.J.; Oma, K.H.; Smith, R.I.; Bunnell, L.R.

    1986-07-01

    Alternative treatments were considered for both existing commercial transuranic wastes and future wastes from spent fuel rod consolidation. Waste treatment was assumed to occur at a hypothetical central treatment facility (a Monitored Retrieval Storage [MRS] facility was used as a reference). Disposal of the waste in a geologic repository was also assumed. The waste form charcteristics, process characteristics, and costs were evaluated for each waste treatment alternative. The evaluation indicated that selection of a high volume reduction alternative can save almost $1 billion in life-cycle costs for the management of transuranic and high-activity wastes from 70,000 MTU of spent fuel compared to the reference MRS waste treatment processes. The supercompaction, arc pyrolysis and melting, and maximum volume reduction alternatives are recommended for further consideration; the latter two are recommended for further testing and demonstration

  11. Studies on coagulation, fibrinolysis, kallikrein-kinin and complement activation in systemic and pulmonary circulation during hip arthroplasty with acrylic cement.

    Science.gov (United States)

    Dahl, O E; Molnar, I; Vinje, A; Rø, J S; Kierulf, P; Andersen, A B; Dalaker, K; Prydz, H

    1988-06-15

    This study was designed to evaluate the contribution of the plasma cascade systems to the cardiopulmonary complications, occasionally leading to sudden death during hip arthroplasty using acrylic cement. The intraoperative pattern following uneventful surgery was therefore investigated in 8 patients with osteoarthrosis with frequent sampling from the radial and pulmonary arteries. The following general findings emerged: A gradual consumption of coagulation factors (platelets, fibrinogen, factor VII, antithrombin III), fibrinolytic components (plasminogen, alpha-2-antiplasmin), kallikrein-kinin factors (prekallikrein, kallikrein inhibitor) and complement factors (C3c, C4) was observed. Some intrapulmonary proteolytic inhibition was noticed as evidenced by lower arterial than mixed venous blood levels of alpha-2-antiplasmin and kallikrein inhibitor. Insignificant changes occurred for factor VII-phospholipid complex. A rapid, massive and transient increase in fibrinopeptide A (FPA) values in the radial artery, as opposed to the moderate increase in the pulmonary artery, was found immediately after reaming and broaching of bone. This probably reflected intrapulmonary fibrinogen to fibrin conversion, reaching a maximum 15-20 minutes before the femoral implantation. As estimated from the FPA arterial peak values and the fall in fibrinogen concentrations, approximately 5-10% of the circulating fibrinogen molecules were devoided of FPA during this intraoperative phase. The marked a-v difference in FPA level supports earlier findings of intrapulmonary fibrin formation and deposition. This process, however preceded the critical period of cardiorespiratory collapse (CRC) by at least 15 minutes, and may thus predispose to this complication.

  12. In vitro and in situ activation of the complement system by the fungus Lacazia loboi Ativação in vitro e in situ do sistema complemento pelo fungo Lacazia loboi

    Directory of Open Access Journals (Sweden)

    Fátima Regina Vilani-Moreno

    2007-04-01

    Full Text Available Since there are no studies evaluating the participation of the complement system (CS in Jorge Lobo's disease and its activity on the fungus Lacazia loboi, we carried out the present investigation. Fungal cells with a viability index of 48% were obtained from the footpads of BALB/c mice and incubated with a pool of inactivated serum from patients with the mycosis or with sterile saline for 30 min at 37 ºC. Next, the tubes were incubated for 2 h with a pool of noninactivated AB+ serum, inactivated serum, serum diluted in EGTA-MgCl2, and serum diluted in EDTA. The viability of L. loboi was evaluated and the fungal suspension was cytocentrifuged. The slides were submitted to immunofluorescence staining using human anti-C3 antibody. The results revealed that 98% of the fungi activated the CS by the alternative pathway and no significant difference in L. loboi viability was observed after CS activation. In parallel, frozen histological sections from 11 patients were analyzed regarding the presence of C3 and IgG by immunofluorescence staining. C3 and IgG deposits were observed in the fungal wall of 100% and 91% of the lesions evaluated, respectively. The results suggest that the CS and immunoglobulins may contribute to the defense mechanisms of the host against L. loboi.Considerando que não existe nenhum estudo avaliando a participação do sistema complemento (SC na doença de Jorge Lobo e sua atividade sobre o fungo Lacazia loboi, realizamos o presente trabalho. Os fungos foram obtidos dos coxins plantares de camundongos BALB/c com índice de viabilidade de 48% e, em seguida, foram incubados com pool de soro inativado de pacientes ou com solução salina estéril (SSE por 30 min, a 37 ºC. Os tubos foram incubados, por 2 h, com pool de soro AB+ sem inativar, inativado, diluído em EGTA-MgCl2 e EDTA. A viabilidade do L. loboi foi avaliada e a suspensão fúngica foi citocentrifugada. As lâminas foram submetidas à técnica de imunofluoresc

  13. Combining fluidized activated carbon with weak alternating electric fields for disinfection

    NARCIS (Netherlands)

    Racyte, J.; Sharabati, J.; Paulitsch-Fuchs, A.H.; Yntema, D.R.; Mayer, M.J.J.; Bruning, H.; Rijnaarts, H.H.M.

    2011-01-01

    This study presents fluidized bed electrodes as a new device for disinfection. In the fluidized bed electrodes system, granular activated carbon particles were suspended, and an alternating radio frequency electric field was applied over the suspended bed. Proof-of-principle studies with the

  14. Alternative Fuels and Hybrid Technology: A Classroom Activity Designed to Evaluate a Contemporary Problem

    Science.gov (United States)

    Roy MacArthur, Amy H.; Copper, Christine L.

    2009-01-01

    As petroleum reserves are being depleted worldwide and energy costs are increasing, the use of alternative fuels is being more widely considered as a solution to the impending energy crisis. In this classroom activity students are presented with a real-world problem in which they must evaluate the properties and environmental impacts of a variety…

  15. Complement fixation test to C burnetii

    Science.gov (United States)

    ... complement fixation test; Coxiella burnetii - complement fixation test; C burnetii - complement fixation test ... a specific foreign substance ( antigen ), in this case, C burnetii . Antibodies defend the body against bacteria, viruses, ...

  16. Complement evasion by Bordetella pertussis: implications for improving current vaccines.

    Science.gov (United States)

    Jongerius, Ilse; Schuijt, Tim J; Mooi, Frits R; Pinelli, Elena

    2015-04-01

    Bordetella pertussis causes whooping cough or pertussis, a highly contagious disease of the respiratory tract. Despite high vaccination coverage, reported cases of pertussis are rising worldwide and it has become clear that the current vaccines must be improved. In addition to the well-known protective role of antibodies and T cells during B. pertussis infection, innate immune responses such as the complement system play an essential role in B. pertussis killing. In order to evade this complement activation and colonize the human host, B. pertussis expresses several molecules that inhibit complement activation. Interestingly, one of the known complement evasion proteins, autotransporter Vag8, is highly expressed in the recently emerged B. pertussis isolates. Here, we describe the current knowledge on how B. pertussis evades complement-mediated killing. In addition, we compare this to complement evasion strategies used by other bacterial species. Finally, we discuss the consequences of complement evasion by B. pertussis on adaptive immunity and how identification of the bacterial molecules and the mechanisms involved in complement evasion might help improve pertussis vaccines.

  17. Complement Attack against Aspergillus and Corresponding Evasion Mechanisms

    Directory of Open Access Journals (Sweden)

    Cornelia Speth

    2012-01-01

    Full Text Available Invasive aspergillosis shows a high mortality rate particularly in immunocompromised patients. Perpetually increasing numbers of affected patients highlight the importance of a clearer understanding of interactions between innate immunity and fungi. Innate immunity is considered to be the most significant host defence against invasive fungal infections. Complement represents a crucial part of this first line defence and comprises direct effects against invading pathogens as well as bridging functions to other parts of the immune network. However, despite the potency of complement to attack foreign pathogens, the prevalence of invasive fungal infections is increasing. Two possible reasons may explain that phenomenon: First, complement activation might be insufficient for an effective antifungal defence in risk patients (due to, e.g., low complement levels, poor recognition of fungal surface, or missing interplay with other immune elements in immunocompromised patients. On the other hand, fungi may have developed evasion strategies to avoid recognition and/or eradication by complement. In this review, we summarize the most important interactions between Aspergillus and the complement system. We describe the various ways of complement activation by Aspergillus and the antifungal effects of the system, and also show proven and probable mechanisms of Aspergillus for complement evasion.

  18. Defining the complement biomarker profile of c3 glomerulopathy

    DEFF Research Database (Denmark)

    Zhang, Yuzhou; Nester, Carla M; Martin, Bertha

    2014-01-01

    BACKGROUND AND OBJECTIVES: C3 glomerulopathy (C3G) applies to a group of renal diseases defined by a specific renal biopsy finding: a dominant pattern of C3 fragment deposition on immunofluorescence. The primary pathogenic mechanism involves abnormal control of the alternative complement pathway......, although a full description of the disease spectrum remains to be determined. This study sought to validate and define the association of complement dysregulation with C3G and to determine whether specific complement pathway abnormalities could inform disease definition. DESIGN, SETTING, PARTICIPANTS......, & MEASUREMENTS: This study included 34 patients with C3G (17 with C3 glomerulonephritis [C3GN] and 17 with dense deposit disease [DDD]) diagnosed between 2008 and 2013 selected from the C3G Registry. Control samples (n=100) were recruited from regional blood drives. Nineteen complement biomarkers were assayed...

  19. Force Dynamics of Verb Complementation

    Directory of Open Access Journals (Sweden)

    Jacek Woźny

    2015-12-01

    Full Text Available Force Dynamics of Verb Complementation The concepts of motion and force are both extensively discussed in cognitive linguistics literature. But they are discussed separately. The first usually in the context of ‘motion situations’ (Talmy, Slobin, Zlatev, the other as part of the Force Dynamics framework, which was developed by Talmy. The aim of this paper is twofold: first, to argue that the concepts of force and motion should not be isolated but considered as two inseparable parts of force-motion events. The second goal is to prove that the modified Force Dynamics (force-motion framework can be used for precise characterization of the verb complementation patterns. To this end, a random sample of 50 sentences containing the verb ‘went’ is analyzed, demonstrating the differences between the categories of intensive and intransitive complementation with respect to the linguistically coded parameters of force and motion.

  20. Redefining the transcriptional regulatory dynamics of classically and alternatively activated macrophages by deepCAGE transcriptomics

    KAUST Repository

    Roy, S.

    2015-06-27

    Classically or alternatively activated macrophages (M1 and M2, respectively) play distinct and important roles for microbiocidal activity, regulation of inflammation and tissue homeostasis. Despite this, their transcriptional regulatory dynamics are poorly understood. Using promoter-level expression profiling by non-biased deepCAGE we have studied the transcriptional dynamics of classically and alternatively activated macrophages. Transcription factor (TF) binding motif activity analysis revealed four motifs, NFKB1_REL_RELA, IRF1,2, IRF7 and TBP that are commonly activated but have distinct activity dynamics in M1 and M2 activation. We observe matching changes in the expression profiles of the corresponding TFs and show that only a restricted set of TFs change expression. There is an overall drastic and transient up-regulation in M1 and a weaker and more sustainable up-regulation in M2. Novel TFs, such as Thap6, Maff, (M1) and Hivep1, Nfil3, Prdm1, (M2) among others, were suggested to be involved in the activation processes. Additionally, 52 (M1) and 67 (M2) novel differentially expressed genes and, for the first time, several differentially expressed long non-coding RNA (lncRNA) transcriptome markers were identified. In conclusion, the finding of novel motifs, TFs and protein-coding and lncRNA genes is an important step forward to fully understand the transcriptional machinery of macrophage activation.

  1. Induction of complement proteins in a mouse model for cerebral microvascular Aβ deposition

    Directory of Open Access Journals (Sweden)

    DeFilippis Kelly

    2007-09-01

    Full Text Available Abstract The deposition of amyloid β-protein (Aβ in cerebral vasculature, known as cerebral amyloid angiopathy (CAA, is a common pathological feature of Alzheimer's disease and related disorders. In familial forms of CAA single mutations in the Aβ peptide have been linked to the increase of vascular Aβ deposits accompanied by a strong localized activation of glial cells and elevated expression of neuroinflammatory mediators including complement proteins. We have developed human amyloid-β precursor protein transgenic mice harboring two CAA Aβ mutations (Dutch E693Q and Iowa D694N that mimic the prevalent cerebral microvascular Aβ deposition observed in those patients, and the Swedish mutations (K670N/M671L to increase Aβ production. In these Tg-SwDI mice, we have reported predominant fibrillar Aβ along microvessels in the thalamic region and diffuse plaques in cortical region. Concurrently, activated microglia and reactive astrocytes have been detected primarily in association with fibrillar cerebral microvascular Aβ in this model. Here we show that three native complement components in classical and alternative complement pathways, C1q, C3, and C4, are elevated in Tg-SwDI mice in regions rich in fibrillar microvascular Aβ. Immunohistochemical staining of all three proteins was increased in thalamus, hippocampus, and subiculum, but not frontal cortex. Western blot analysis showed significant increases of all three proteins in the thalamic region (with hippocampus as well as the cortical region, except C3 that was below detection level in cortex. Also, in the thalamic region (with hippocampus, C1q and C3 mRNAs were significantly up-regulated. These complement proteins appeared to be expressed largely by activated microglial cells associated with the fibrillar microvascular Aβ deposits. Our findings demonstrate that Tg-SwDI mice exhibit elevated complement protein expression in response to fibrillar vascular Aβ deposition that is

  2. Expression, purification, cocrystallization and preliminary crystallographic analysis of sucrose octasulfate/human complement regulator factor H SCRs 6–8

    Energy Technology Data Exchange (ETDEWEB)

    Prosser, Beverly E.; Johnson, Steven; Roversi, Pietro [The Sir William Dunn School of Pathology, The University of Oxford, South Parks Road, Oxford OX1 3RE (United Kingdom); Clark, Simon J. [Faculty of Life Sciences, Manchester University, Michael Smith Building, Oxford Road, Manchester M13 9PT (United Kingdom); Tarelli, Edward [Medical Biomics Centre, St George’s, University of London, Cranmer Terrace, London SW17 0RE (United Kingdom); Sim, Robert B. [The MRC Immunochemistry Unit, The University of Oxford, South Parks Road, Oxford OX1 3RE (United Kingdom); Day, Antony J. [Faculty of Life Sciences, Manchester University, Michael Smith Building, Oxford Road, Manchester M13 9PT (United Kingdom); Lea, Susan M., E-mail: susan.lea@bnc.ox.ac.uk [The Sir William Dunn School of Pathology, The University of Oxford, South Parks Road, Oxford OX1 3RE (United Kingdom)

    2007-06-01

    The crystallization of human complement regulator FH-678{sub 402H} with a glycosaminoglycan analogue is described. Human plasma protein complement factor H (FH) is an inhibitor of the spontaneously activated alternative complement pathway. An allotypic variant of FH, 402His, has been associated with age-related macular degeneration, the leading cause of blindness in the elderly. Crystals of FH domains 6–8 (FH678) containing 402His have been grown in the presence of a polyanionic sucrose octasulfate ligand (an analogue of the natural glycosaminoglycan ligands of FH) using both native and selenomethionine-derivatized protein. Native data sets diffracting to 2.3 Å and SeMet data sets of up to 2.8 Å resolution have been collected. An anomalous difference Patterson map reveals self- and cross-peaks from two incorporated Se atoms. The corresponding selenium substructure has been solved.

  3. An Alternate Splicing Variant of the Human Telomerase Catalytic Subunit Inhibits Telomerase Activity

    Directory of Open Access Journals (Sweden)

    Xiaoming Yi

    2000-09-01

    Full Text Available Telomerase, a cellular reverse transcriptase, adds telomeric repeats to chromosome ends. In normal human somatic cells, telomerase is repressed and telomeres progressively shorten, leading to proliferative senescence. Introduction of the telomerase (hTERT cDNA is sufficient to produce telomerase activity and immortalize normal human cells, suggesting that the repression of telomerase activity is transcriptional. The telomerase transcript has been shown to have at least six alternate splicing sites (four insertion sites and two deletion sites, and variants containing both or either of the deletion sites are present during development and in a panel of cancer cell lines we surveyed. One deletion (β site and all four insertions cause premature translation terminations, whereas the other deletion (α site is 36 by and lies within reverse transcriptase (RT motif A, suggesting that this deletion variant may be a candidate as a dominant-negative inhibitor of telomerase. We have cloned three alternately spliced hTERT variants that contain the α,β or both α and,β deletion sites. These alternate splicing variants along with empty vector and wild-type hTERT were introduced into normal human fibroblasts and several telomerase-positive immortal and tumor cell lines. Expression of the α site deletion variant (hTERT α− construct was confirmed by Western blotting. We found that none of the three alternate splicing variants reconstitutes telomerase activity in fibroblasts. However, hTERT α− inhibits telomerase activities in telomerase-positive cells, causes telomere shortening and eventually cell death. This alternately spliced dominant-negative variant may be important in understanding telomerase regulation during development, differentiation and in cancer progression.

  4. Alternatively activated macrophages (M2 macrophages) in the skin of patient with localized scleroderma.

    Science.gov (United States)

    Higashi-Kuwata, Nobuyo; Makino, Takamitsu; Inoue, Yuji; Takeya, Motohiro; Ihn, Hironobu

    2009-08-01

    Localized scleroderma is a connective tissue disorder that is limited to the skin and subcutaneous tissue. Macrophages have been reported to be particularly activated in patients with skin disease including systemic sclerosis and are potentially important sources for fibrosis-inducing cytokines, such as transforming growth factor beta. To clarify the features of immunohistochemical characterization of the immune cell infiltrates in localized scleroderma focusing on macrophages, skin biopsy specimens were analysed by immunohistochemistry. The number of cells stained with monoclonal antibodies, CD68, CD163 and CD204, was calculated. An evident macrophage infiltrate and increased number of alternatively activated macrophages (M2 macrophages) in their fibrotic areas were observed along with their severity of inflammation. This study revealed that alternatively activated macrophages (M2 macrophages) may be a potential source of fibrosis-inducing cytokines in localized scleroderma, and may play a crucial role in the pathogenesis of localized scleroderma.

  5. Developmentally regulated expression by Trypanosoma cruzi of molecules that accelerate the decay of complement C3 convertases

    International Nuclear Information System (INIS)

    Rimoldi, M.T.; Sher, A.; Heiny, A.; Lituchy, A.; Hammer, C.H.; Joiner, K.

    1988-01-01

    The authors recently showed that culture-derived metacyclic trypomastigotes (CMT), but not epimastigotes (Epi), of the Miranda 99 strain of Trypanosoma cruzi evade lysis by the human alternative complement pathway because of inefficient binding of factor B to complement component C3b on the parasite surface. These results suggested that CMT and tissue-culture-derived trypomastigotes (TCT), which also activate the alternative pathway poorly, might produce a molecule capable of interfering with factor B binding to C3b. They now demonstrate that CMT and TCT lysates, as well as molecules spontaneously shed from CMT and TCT but not Epi, accelerate decay of 125 I-labeled factor Bb from the alternative-pathway C3 convertase (C3bBb) assembled on zymosan or Epi and also accelerate decay of the classical-pathway C3 convertase (C4b2a) on sheep erythrocytes. Parasites metabolically labeled with [ 35 S]methionine spontaneously shed a limited number of radioactive components, ranging in molecular mass from 86 to 155 kDa for trypomastigotes and 25 to 80 kDa for Epi. Decay-accelerating activity within supernatants is inactivated by papain and is coeluted with 35 S-containing polypeptides on FPLC anion-exchange chromatography, suggesting that the active constituents are protein molecules. Molecules with decay-accelerating activity may explain the developmentally regulated resistance to complement-mediated lysis in infective and vertebrate stages for T. cruzi life cycle

  6. Evaluation of complement proteins as screening markers for colorectal cancer

    DEFF Research Database (Denmark)

    Storm, Line; Christensen, Ib J; Jensenius, Jens C

    2015-01-01

    BACKGROUND: Colorectal cancer (CRC) is a leading cause of cancer death worldwide. Lack of symptoms results in late detection and increased mortality. Inflammation, including complement activation, plays an important role in tumorigenesis. EXPERIMENTAL DESIGN: The concentrations of nine proteins...

  7. Detection of telomerase activity by the TRAP assay and its variants and alternatives.

    Science.gov (United States)

    Fajkus, Jirí

    2006-09-01

    Telomerase activity is closely connected to problems of cellular immortality, proliferative capacity, differentiation, cancer and aging. Correspondingly, techniques for its detection have been essential for progress in telomere biology and are of still increasing importance in molecular diagnostics and therapy of cancer. This article reviews the development of the telomere repeat amplification protocol (TRAP) and its various modifications as the most widespread assay to detect and measure telomerase activity. Alternative possibilities of telomerase activity detection are also discussed which make it possible to omit the PCR-mediated amplification of telomerase products. These approaches are based on recent advances in highly sensitive detection systems.

  8. Inactivation of complement by Loxosceles reclusa spider venom.

    Science.gov (United States)

    Gebel, H M; Finke, J H; Elgert, K D; Cambell, B J; Barrett, J T

    1979-07-01

    Zymosan depletion of serum complement in guinea pigs rendered them highly resistant to lesion by Loxosceles reclusa spider venom. Guinea pigs deficient in C4 of the complement system are as sensitive to the venom as normal guinea pigs. The injection of 35 micrograms of whole recluse venom intradermally into guinea pigs lowered their complement level by 35.7%. Brown recluse spider venom in concentrations as slight as 0.02 micrograms protein/ml can totally inactivate one CH50 of guinea pig complement in vitro. Bee, scorpion, and other spider venoms had no influence on the hemolytic titer of complement. Fractionation of recluse spider venom by Sephadex G-200 filtration separated the complement-inactivating property of the venom into three major regions which could be distinguished on the basis of heat stability as well as size. None was neutralized by antivenom. Polyacrylamide gel electrophoresis of venom resolved the complement inactivators into five fractions. Complement inactivated by whole venom or the Sephadex fractions could be restored to hemolytic activity by supplements of fresh serum but not by heat-inactivated serum, pure C3, pure C5, or C3 and C5 in combination.

  9. Molecular Characterization of the Rhesus Rhadinovirus (RRV) ORF4 Gene and the RRV Complement Control Protein It Encodes▿

    Science.gov (United States)

    Mark, Linda; Spiller, O. Brad; Okroj, Marcin; Chanas, Simon; Aitken, Jim A.; Wong, Scott W.; Damania, Blossom; Blom, Anna M.; Blackbourn, David J.

    2007-01-01

    The diversity of viral strategies to modulate complement activation indicates that this component of the immune system has significant antiviral potential. One example is the Kaposi's sarcoma-associated herpesvirus (KSHV) complement control protein (KCP), which inhibits progression of the complement cascade. Rhesus rhadinovirus (RRV), like KSHV, is a member of the subfamily Gammaherpesvirinae and currently provides the only in vivo model of KSHV pathobiology in primates. In the present study, we characterized the KCP homologue encoded by RRV, RRV complement control protein (RCP). Two strains of RRV have been sequenced to date (H26-95 and 17577), and the RCPs they encode differ substantially in structure: RCP from strain H26-95 has four complement control protein (CCP) domains, whereas RCP from strain 17577 has eight CCP domains. Transcriptional analyses of the RCP gene (ORF4, referred to herein as RCP) in infected rhesus macaque fibroblasts mapped the ends of the transcripts of both strains. They revealed that H26-95 encodes a full-length, unspliced RCP transcript, while 17577 RCP generates a full-length unspliced mRNA and two alternatively spliced transcripts. Western blotting confirmed that infected cells express RCP, and immune electron microscopy disclosed this protein on the surface of RRV virions. Functional studies of RCP encoded by both RRV strains revealed their ability to suppress complement activation by the classical (antibody-mediated) pathway. These data provide the foundation for studies into the biological significance of gammaherpesvirus complement regulatory proteins in a tractable, non-human primate model. PMID:17287274

  10. Critical illness induces alternative activation of M2 macrophages in adipose tissue.

    Science.gov (United States)

    Langouche, Lies; Marques, Mirna B; Ingels, Catherine; Gunst, Jan; Derde, Sarah; Vander Perre, Sarah; D'Hoore, André; Van den Berghe, Greet

    2011-01-01

    We recently reported macrophage accumulation in adipose tissue of critically ill patients. Classically activated macrophage accumulation in adipose tissue is a known feature of obesity, where it is linked with increasing insulin resistance. However, the characteristics of adipose tissue macrophage accumulation in critical illness remain unknown. We studied macrophage markers with immunostaining and gene expression in visceral and subcutaneous adipose tissue from healthy control subjects (n = 20) and non-surviving prolonged critically ill patients (n = 61). For comparison, also subcutaneous in vivo adipose tissue biopsies were studied from 15 prolonged critically ill patients. Subcutaneous and visceral adipose tissue biopsies from non-surviving prolonged critically ill patients displayed a large increase in macrophage staining. This staining corresponded with elevated gene expression of "alternatively activated" M2 macrophage markers arginase-1, IL-10 and CD163 and low levels of the "classically activated" M1 macrophage markers tumor necrosis factor (TNF)-α and inducible nitric-oxide synthase (iNOS). Immunostaining for CD163 confirmed positive M2 macrophage staining in both visceral and subcutaneous adipose tissue biopsies from critically ill patients. Surprisingly, circulating levels and tissue gene expression of the alternative M2 activators IL-4 and IL-13 were low and not different from controls. In contrast, adipose tissue protein levels of peroxisome proliferator-activated receptor-γ (PPARγ), a nuclear receptor required for M2 differentiation and acting downstream of IL-4, was markedly elevated in illness. In subcutaneous abdominal adipose tissue biopsies from surviving critically ill patients, we could confirm positive macrophage staining with CD68 and CD163. We also could confirm elevated arginase-1 gene expression and elevated PPARγ protein levels. Unlike obesity, critical illness evokes adipose tissue accumulation of alternatively activated M2

  11. Bohm's mysterious 'quantum force' and 'active information': alternative interpretation and statistical properties

    International Nuclear Information System (INIS)

    Lan, B.L.

    2001-01-01

    An alternative interpretation to Bohm's 'quantum force' and 'active information' is proposed. Numerical evidence is presented, which suggests that the time series of Bohm's 'quantum force' evaluated at the Bohmian position for non-stationary quantum states are typically non-Gaussian stable distributed with a flat power spectrum in classically chaotic Hamiltonian systems. An important implication of these statistical properties is briefly mentioned. (orig.)

  12. Effects of radiographic contrast media on the serum complement system

    International Nuclear Information System (INIS)

    Tirone, P.; Boldrini, E.

    1983-01-01

    The authors explored the activation of the complement system produced by a nonionic organic iodine compound, namely iopamidol, which is proposed as a contrast medium for radiographic examination by intravenous and intra-arterial injection. The study was conducted in vitro versus established ionic contrasts (diatrizoate, iothalamate, acetrizoate) and a nonionic compound (metrizamide). The adopted experimental model was the immunohemolytic detector system, in which the immune complex consisted of goat erythrocytes sensitized with the corresponding antibody (hemolysin), and complement (C') was supplied by guinea pig serum. All the products caused complement activation. The results show that nonionic contrast media produce less activation of the complement system than the traditional ionic contrast. Thus the use of nonionic contrast for radiological procedures necessitating the introduction of contrast material into the blood compartment would imply a reduced risk of anaphylactoid reactions. (orig.)

  13. Plasma complement and vascular complement deposition in patients with coronary artery disease with and without inflammatory rheumatic diseases

    Science.gov (United States)

    2017-01-01

    Purpose Inflammatory rheumatic diseases (IRD) are associated with accelerated coronary artery disease (CAD), which may result from both systemic and vascular wall inflammation. There are indications that complement may be involved in the pathogenesis of CAD in Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA). This study aimed to evaluate the associations between circulating complement and complement activation products with mononuclear cell infiltrates (MCI, surrogate marker of vascular inflammation) in the aortic media and adventitia in IRDCAD and non-IRDCAD patients undergoing coronary artery bypass grafting (CABG). Furthermore, we compared complement activation product deposition patterns in rare aorta adventitial and medial biopsies from SLE, RA and non-IRD patients. Methods We examined plasma C3 (p-C3) and terminal complement complexes (p-TCC) in 28 IRDCAD (SLE = 3; RA = 25), 52 non-IRDCAD patients, and 32 IRDNo CAD (RA = 32) from the Feiring Heart Biopsy Study. Aortic biopsies taken from the CAD only patients during CABG were previously evaluated for adventitial MCIs. The rare aortic biopsies from 3 SLE, 3 RA and 3 non-IRDCAD were assessed for the presence of C3 and C3d using immunohistochemistry. Results IRDCAD patients had higher p-TCC than non-IRDCAD or IRDNo CAD patients (prheumatic disease, and, in particular, SLE with the complement system. Exaggerated systemic and vascular complement activation may accelerate CVD, serve as a CVD biomarker, and represent a target for new therapies. PMID:28362874

  14. Characterization and expression analysis of a complement component gene in sea cucumber ( Apostichopus japonicus)

    Science.gov (United States)

    Chen, Zhong; Zhou, Zunchun; Yang, Aifu; Dong, Ying; Guan, Xiaoyan; Jiang, Bei; Wang, Bai

    2015-12-01

    The complement system plays a crucial role in the innate immune system of animals. It can be activated by distinct yet overlapping classical, alternative and lectin pathways. In the alternative pathway, complement factor B (Bf) serves as the catalytic subunit of complement component 3 (C3) convertase, which plays the central role among three activation pathways. In this study, the Bf gene in sea cucumber ( Apostichopus japonicus), termed AjBf, was obtained by rapid amplification of cDNA ends (RACE). The full-length cDNA of AjBf was 3231 bp in length barring the poly (A) tail. It contained an open reading frame (ORF) of 2742 bp encoding 913 amino acids, a 105 bp 5'-UTR (5'-terminal untranslated region) and a 384 bp 3'-UTR. AjBf was a mosaic protein with six CCP (complement control protein) domains, a VWA (von Willebrand factor A) domain, and a serine protease domain. The deduced molecular weight of AjBf protein was 101 kDa. Quantitative real time PCR (qRT-PCR) analysis indicated that the expression level of AjBf in A. japonicus was obviously higher at larval stage than that at embryonic stage. Expression detection in different tissues showed that AjBf expressed higher in coelomocytes than in other four tissues. In addation, AjBf expression in different tissues was induced significantly after LPS or PolyI:C challenge. These results indicated that AjBf plays an important role in immune responses to pathogen infection.

  15. Interpain A, a cysteine proteinase from Prevotella intermedia, inhibits complement by degrading complement factor C3.

    Directory of Open Access Journals (Sweden)

    Michal Potempa

    2009-02-01

    Full Text Available Periodontitis is an inflammatory disease of the supporting structures of the teeth caused by, among other pathogens, Prevotella intermedia. Many strains of P. intermedia are resistant to killing by the human complement system, which is present at up to 70% of serum concentration in gingival crevicular fluid. Incubation of human serum with recombinant cysteine protease of P. intermedia (interpain A resulted in a drastic decrease in bactericidal activity of the serum. Furthermore, a clinical strain 59 expressing interpain A was more serum-resistant than another clinical strain 57, which did not express interpain A, as determined by Western blotting. Moreover, in the presence of the cysteine protease inhibitor E64, the killing of strain 59 by human serum was enhanced. Importantly, we found that the majority of P. intermedia strains isolated from chronic and aggressive periodontitis carry and express the interpain A gene. The protective effect of interpain A against serum bactericidal activity was found to be attributable to its ability to inhibit all three complement pathways through the efficient degradation of the alpha-chain of C3 -- the major complement factor common to all three pathways. P. intermedia has been known to co-aggregate with P. gingivalis, which produce gingipains to efficiently degrade complement factors. Here, interpain A was found to have a synergistic effect with gingipains on complement degradation. In addition, interpain A was able to activate the C1 complex in serum, causing deposition of C1q on inert and bacterial surfaces, which may be important at initial stages of infection when local inflammatory reaction may be beneficial for a pathogen. Taken together, the newly characterized interpain A proteinase appears to be an important virulence factor of P. intermedia.

  16. Alternative Splicing of the Pituitary Adenylate Cyclase-Activating Polypeptide Receptor PAC1: Mechanisms of Fine Tuning of Brain Activity

    Directory of Open Access Journals (Sweden)

    Janna eBlechman

    2013-05-01

    Full Text Available Alternative splicing of the precursor mRNA encoding for the neuropeptide receptor PAC1/ADCYAP1R1 generates multiple protein products that exhibit pleiotropic activities. Recent studies in mammals and zebrafish have implicated some of these splice isoforms in control of both cellular and body homeostasis. Here, we review the regulation of PAC1 splice variants and their underlying signal transduction and physiological processes in the nervous system.

  17. Oxidized LDL Induces Alternative Macrophage Phenotype through Activation of CD36 and PAFR

    Directory of Open Access Journals (Sweden)

    Francisco J. Rios

    2013-01-01

    Full Text Available OxLDL is recognized by macrophage scavenger receptors, including CD36; we have recently found that Platelet-Activating Factor Receptor (PAFR is also involved. Since PAFR in macrophages is associated with suppressor function, we examined the effect of oxLDL on macrophage phenotype. It was found that the presence of oxLDL during macrophage differentiation induced high mRNA levels to IL-10, mannose receptor, PPARγ and arginase-1 and low levels of IL-12 and iNOS. When human THP-1 macrophages were pre-treated with oxLDL then stimulated with LPS, the production of IL-10 and TGF-β significantly increased, whereas that of IL-6 and IL-8 decreased. In murine TG-elicited macrophages, this protocol significantly reduced NO, iNOS and COX2 expression. Thus, oxLDL induced macrophage differentiation and activation towards the alternatively activated M2-phenotype. In murine macrophages, oxLDL induced TGF-β, arginase-1 and IL-10 mRNA expression, which were significantly reduced by pre-treatment with PAFR antagonists (WEB and CV or with antibodies to CD36. The mRNA expression of IL-12, RANTES and CXCL2 were not affected. We showed that this profile of macrophage activation is dependent on the engagement of both CD36 and PAFR. We conclude that oxLDL induces alternative macrophage activation by mechanisms involving CD36 and PAFR.

  18. On the influence of the alternation of two different cooling systems on dairy cow daily activities

    Directory of Open Access Journals (Sweden)

    Simona M.C. Porto

    2017-02-01

    Full Text Available Among the causes that influence cow welfare, heat stress induced by microclimatic conditions is one of the most relevant and many studies have investigated the efficacy of different cooling systems on animal health status. Nevertheless, the direct influence of the cooling systems on possible modifications of dairy cow behaviour has been addressed in a few studies and the related results were affected by the presence of a paddock, which gave a refuge from hot temperature. Since an alteration of the daily time budget spent by dairy cows in their usual activities can be associated with changes in their health status, this study investigated the effects of the alternation of two different cooling systems on lying, standing, and feeding behaviour of a group of dairy cows bred in a free-stall dairy house where animals had no access to a paddock. The barn was equipped with a fogging system associated with forced ventilation installed in the resting area and a sprinkler system associated with forced ventilation installed in the feeding area. The two systems were activated alternately. The results demonstrated that the management of the two cooling systems affected the analysed behaviours. Though the activation of the cooling system installed in the resting area encouraged the decubitus of animals in the stalls, the activation of that one of the feeding alley could not be able to influence the standing behaviour and had only a moderate positive influence on the feeding activity.

  19. The lectin pathway of complement

    DEFF Research Database (Denmark)

    Ballegaard, Vibe Cecilie Diederich; Haugaard, Anna Karen; Garred, P

    2014-01-01

    The pattern recognition molecules of the lectin complement pathway are important components of the innate immune system with known functions in host-virus interactions. This paper summarizes current knowledge of how these intriguing molecules, including mannose-binding lectin (MBL), Ficolin-1, -2......-1, -2 and -3 and CL-11 could have similar functions in HIV infection as the ficolins have been shown to play a role in other viral infections, and CL-11 resembles MBL and the ficolins in structure and binding capacity.......The pattern recognition molecules of the lectin complement pathway are important components of the innate immune system with known functions in host-virus interactions. This paper summarizes current knowledge of how these intriguing molecules, including mannose-binding lectin (MBL), Ficolin-1, -2...

  20. Complement's participation in acquired immunity

    DEFF Research Database (Denmark)

    Nielsen, Claus Henrik; Leslie, Robert Graham Quinton

    2002-01-01

    of the B cell receptor for antigen (BCR), a complex composed of the iC3b/C3d fragment-binding complement type 2 receptor (CR2, CD21) and its signaling element CD19 and the IgG-binding receptor FcgammaRIIb (CD32). The positive or negative outcome of signaling through this triad is determined by the context...

  1. Accurate Assessment of the Oxygen Reduction Electrocatalytic Activity of Mn/Polypyrrole Nanocomposites Based on Rotating Disk Electrode Measurements, Complemented with Multitechnique Structural Characterizations

    Science.gov (United States)

    Sánchez, Carolina Ramírez; Taurino, Antonietta; Bozzini, Benedetto

    2016-01-01

    This paper reports on the quantitative assessment of the oxygen reduction reaction (ORR) electrocatalytic activity of electrodeposited Mn/polypyrrole (PPy) nanocomposites for alkaline aqueous solutions, based on the Rotating Disk Electrode (RDE) method and accompanied by structural characterizations relevant to the establishment of structure-function relationships. The characterization of Mn/PPy films is addressed to the following: (i) morphology, as assessed by Field-Emission Scanning Electron Microscopy (FE-SEM) and Atomic Force Microscope (AFM); (ii) local electrical conductivity, as measured by Scanning Probe Microscopy (SPM); and (iii) molecular structure, accessed by Raman Spectroscopy; these data provide the background against which the electrocatalytic activity can be rationalised. For comparison, the properties of Mn/PPy are gauged against those of graphite, PPy, and polycrystalline-Pt (poly-Pt). Due to the literature lack of accepted protocols for precise catalytic activity measurement at poly-Pt electrode in alkaline solution using the RDE methodology, we have also worked on the obtainment of an intralaboratory benchmark by evidencing some of the time-consuming parameters which drastically affect the reliability and repeatability of the measurement. PMID:28042491

  2. Accurate Assessment of the Oxygen Reduction Electrocatalytic Activity of Mn/Polypyrrole Nanocomposites Based on Rotating Disk Electrode Measurements, Complemented with Multitechnique Structural Characterizations

    Directory of Open Access Journals (Sweden)

    Patrizia Bocchetta

    2016-01-01

    Full Text Available This paper reports on the quantitative assessment of the oxygen reduction reaction (ORR electrocatalytic activity of electrodeposited Mn/polypyrrole (PPy nanocomposites for alkaline aqueous solutions, based on the Rotating Disk Electrode (RDE method and accompanied by structural characterizations relevant to the establishment of structure-function relationships. The characterization of Mn/PPy films is addressed to the following: (i morphology, as assessed by Field-Emission Scanning Electron Microscopy (FE-SEM and Atomic Force Microscope (AFM; (ii local electrical conductivity, as measured by Scanning Probe Microscopy (SPM; and (iii molecular structure, accessed by Raman Spectroscopy; these data provide the background against which the electrocatalytic activity can be rationalised. For comparison, the properties of Mn/PPy are gauged against those of graphite, PPy, and polycrystalline-Pt (poly-Pt. Due to the literature lack of accepted protocols for precise catalytic activity measurement at poly-Pt electrode in alkaline solution using the RDE methodology, we have also worked on the obtainment of an intralaboratory benchmark by evidencing some of the time-consuming parameters which drastically affect the reliability and repeatability of the measurement.

  3. Listening to Puns Elicits the Co-Activation of Alternative Homophone Meanings during Language Production.

    Directory of Open Access Journals (Sweden)

    Sebastian Benjamin Rose

    Full Text Available Recent evidence suggests that lexical-semantic activation spread during language production can be dynamically shaped by contextual factors. In this study we investigated whether semantic processing modes can also affect lexical-semantic activation during word production. Specifically, we tested whether the processing of linguistic ambiguities, presented in the form of puns, has an influence on the co-activation of unrelated meanings of homophones in a subsequent language production task. In a picture-word interference paradigm with word distractors that were semantically related or unrelated to the non-depicted meanings of homophones we found facilitation induced by related words only when participants listened to puns before object naming, but not when they heard jokes with unambiguous linguistic stimuli. This finding suggests that a semantic processing mode of ambiguity perception can induce the co-activation of alternative homophone meanings during speech planning.

  4. ALTERNATIVE EQUATIONS FOR DYNAMIC BEHAVIOR OF IONIC CHANNEL ACTIVATION AND INACTIVATION GATES

    Directory of Open Access Journals (Sweden)

    Mahmut ÖZER

    2003-03-01

    Full Text Available In this paper, alternative equations for dynamics of ionic channel activation and inactivation gates are proposed based on the path probability method. Dynamic behavior of a voltage-gated ionic channel is modeled by the conventional Hodgkin-Huxley (H-H mathematical formalism. In that model, conductance of the channel is defined in terms of activation and inactivation gates. Dynamics of the activation and inactivation gates is modeled by first-order differential equations dependent on the gate variable and the membrane potential. In the new approach proposed in this study, dynamic behavior of activation and inactivation gates is modeled by a firstorder differential equation dependent on internal energy and membrane potential by using the path probability method which is widely used in statistical physics. The new model doesn't require the time constant and steadystate values which are used explicitly in the H-H model. The numerical results show validity of the proposed method.

  5. MAG4 versus alternative techniques for forecasting active region flare productivity

    Science.gov (United States)

    Falconer, David A; Moore, Ronald L; Barghouty, Abdulnasser F; Khazanov, Igor

    2014-01-01

    MAG4 is a technique of forecasting an active region's rate of production of major flares in the coming few days from a free magnetic energy proxy. We present a statistical method of measuring the difference in performance between MAG4 and comparable alternative techniques that forecast an active region's major-flare productivity from alternative observed aspects of the active region. We demonstrate the method by measuring the difference in performance between the “Present MAG4” technique and each of three alternative techniques, called “McIntosh Active-Region Class,” “Total Magnetic Flux,” and “Next MAG4.” We do this by using (1) the MAG4 database of magnetograms and major flare histories of sunspot active regions, (2) the NOAA table of the major-flare productivity of each of 60 McIntosh active-region classes of sunspot active regions, and (3) five technique performance metrics (Heidke Skill Score, True Skill Score, Percent Correct, Probability of Detection, and False Alarm Rate) evaluated from 2000 random two-by-two contingency tables obtained from the databases. We find that (1) Present MAG4 far outperforms both McIntosh Active-Region Class and Total Magnetic Flux, (2) Next MAG4 significantly outperforms Present MAG4, (3) the performance of Next MAG4 is insensitive to the forward and backward temporal windows used, in the range of one to a few days, and (4) forecasting from the free-energy proxy in combination with either any broad category of McIntosh active-region classes or any Mount Wilson active-region class gives no significant performance improvement over forecasting from the free-energy proxy alone (Present MAG4). Key Points Quantitative comparison of performance of pairs of forecasting techniques Next MAG4 forecasts major flares more accurately than Present MAG4 Present MAG4 forecast outperforms McIntosh AR Class and total magnetic flux PMID:26213517

  6. Work activities and musculoskeletal discomforts amongst active older Albertans on alternative employment trajectories.

    Science.gov (United States)

    Doan, Jon B; Copeland, Jennifer L; Brown, Lesley A; Newman, Jeff T; Hudson, D Shane

    2014-01-01

    Bridge employment (scheduled paid work after retirement age) may promote successful aging and continued health, as work can be an important component of daily physical activity. Appropriate work demands for older adults are neither well-established nor well-applied, however, and excessive loading or increased perceptions of discomfort may negate the health benefits of work activity. This study examined work status and musculoskeletal discomfort (MSD) amongst older Albertans. 1044 Albertans aged 55 years and older participating in an organized 'Games' received a research package. Enclosed in the package were an introductory letter, a return envelope, and modified versions of validated questionnaires examining leisure and work activities, activity frequency, and perceptions of musculoskeletal health. 228 respondents were classified into one of three employment trajectory groups: fully retired, fully employed, or bridge employed. Groups differed in age, and both employed groups more frequently reported MSDs in all body areas. Bridge employed reported increased 'occasional' frequency of musculoskeletal injury risk factors, while both groups reported similar overall ratings of work-related exertion. The increased MSDs reported by bridge employed adults may be the result of irregularity of work activity and soft tissue loading. Detailed examination of work demands and musculoskeletal injuries amongst bridge employed adults could help define safer levels for less regular work activity.

  7. Influence of complementing a robotic upper limb rehabilitation system with video games on the engagement of the participants: a study focusing on muscle activities.

    Science.gov (United States)

    Li, Chong; Rusák, Zoltán; Horváth, Imre; Ji, Linhong

    2014-12-01

    Efficacious stroke rehabilitation depends not only on patients' medical treatment but also on their motivation and engagement during rehabilitation exercises. Although traditional rehabilitation exercises are often mundane, technology-assisted upper-limb robotic training can provide engaging and task-oriented training in a natural environment. The factors that influence engagement, however, are not fully understood. This paper therefore studies the relationship between engagement and muscle activities as well as the influencing factors of engagement. To this end, an experiment was conducted using a robotic upper limb rehabilitation system with healthy individuals in three training exercises: (a) a traditional exercise, which is typically used for training the grasping function, (b) a tracking exercise, currently used in robot-assisted stroke patient rehabilitation for fine motor movement, and (c) a video game exercise, which is a proliferating approach of robot-assisted rehabilitation enabling high-level active engagement of stroke patients. These exercises differ not only in the characteristics of the motion that they use but also in their method of triggering engagement. To measure the level of engagement, we used facial expressions, motion analysis of the arm movements, and electromyography. The results show that (a) the video game exercise could engage the participants for a longer period than the other two exercises, (b) the engagement level decreased when the participants became too familiar with the exercises, and (c) analysis of normalized root mean square in electromyographic data indicated that muscle activities were more intense when the participants are engaged. This study shows that several sub-factors on engagement, such as versatility of feedback, cognitive tasks, and competitiveness, may influence engagement more than the others. To maintain a high level of engagement, the rehabilitation system needs to be adaptive, providing different exercises to

  8. [Delayed reactions of active avoidance in white rats under conditions of an alternative choice].

    Science.gov (United States)

    Ioseliani, T K; Sikharulidze, N I; Kadagishvili, A Ia; Mitashvili, E G

    1995-01-01

    It was shown that if the rats had been learned and then tested using conventional pain punishment of erroneous choice they were able to solve the problem of alternative choice only in the period of immediate action of conditioned stimuli. If the pain punishment for erroneously chosen compartment had not been applied in animal learning and testing, rats successfully solved the problem of alternative choice even after 5-second delay. Introduction of pain punishment led to the frustration of earlier elaborated delayed avoidance reactions. Analysis of the obtained results allows us to argue that the apparent incapability of white rats for solving the problems of delayed avoidance is caused by simultaneous action of two different mechanisms, i.e., those of the active and passive avoidance rather than short-term memory deficit.

  9. Activity and functional interaction of alternative oxidase and uncoupling protein in mitochondria from tomato fruit

    Directory of Open Access Journals (Sweden)

    F.E. Sluse

    2000-03-01

    Full Text Available Cyanide-resistant alternative oxidase (AOX is not limited to plant mitochondria and is widespread among several types of protists. The uncoupling protein (UCP is much more widespread than previously believed, not only in tissues of higher animals but also in plants and in an amoeboid protozoan. The redox energy-dissipating pathway (AOX and the proton electrochemical gradient energy-dissipating pathway (UCP lead to the same final effect, i.e., a decrease in ATP synthesis and an increase in heat production. Studies with green tomato fruit mitochondria show that both proteins are present simultaneously in the membrane. This raises the question of a specific physiological role for each energy-dissipating system and of a possible functional connection between them (shared regulation. Linoleic acid, an abundant free fatty acid in plants which activates UCP, strongly inhibits cyanide-resistant respiration mediated by AOX. Moreover, studies of the evolution of AOX and UCP protein expression and of their activities during post-harvest ripening of tomato fruit show that AOX and plant UCP work sequentially: AOX activity decreases in early post-growing stages and UCP activity is decreased in late ripening stages. Electron partitioning between the alternative oxidase and the cytochrome pathway as well as H+ gradient partitioning between ATP synthase and UCP can be evaluated by the ADP/O method. This method facilitates description of the kinetics of energy-dissipating pathways and of ATP synthase when state 3 respiration is decreased by limitation of oxidizable substrate.

  10. Dengue-Immune Humans Have Higher Levels of Complement-Independent Enhancing Antibody than Complement-Dependent Neutralizing Antibody.

    Science.gov (United States)

    Yamanaka, Atsushi; Konishi, Eiji

    2017-09-25

    Dengue is the most important arboviral disease worldwide. We previously reported that most inhabitants of dengue-endemic countries who are naturally immune to the disease have infection-enhancing antibodies whose in vitro activity does not decrease in the presence of complement (complement-independent enhancing antibodies, or CiEAb). Here, we compared levels of CiEAb and complement-dependent neutralizing antibodies (CdNAb) in dengue-immune humans. A typical antibody dose-response pattern obtained in our assay system to measure the balance between neutralizing and enhancing antibodies showed both neutralizing and enhancing activities depending on serum dilution factor. The addition of complement to the assay system increased the activity of neutralizing antibodies at lower dilutions, indicating the presence of CdNAb. In contrast, similar dose-response curves were obtained with and without complement at higher dilutions, indicating higher levels of CiEAb than CdNAb. For experimental support for the higher CiEAb levels, a cocktail of mouse monoclonal antibodies against dengue virus type 1 was prepared. The antibody dose-response curves obtained in this assay, with or without complement, were similar to those obtained with human serum samples when a high proportion of D1-V-3H12 (an antibody exhibiting only enhancing activity and thus a model for CiEAb) was used in the cocktail. This study revealed higher-level induction of CiEAb than CdNAb in humans naturally infected with dengue viruses.

  11. Afolayan and Otunola Afr J Tradit Complement Altern Med. (2014 ...

    African Journals Online (AJOL)

    cadewumi

    ULTRASTRUCTURE AND ELEMENTAL ANALYSIS OF HYPOXIS .... Chromium is an essential mineral that is necessary for normal glucose and lipid homeostasis especially in .... Magnesium intake and risk of type 2 diabetes: a Meta analysis.

  12. Semenya and Potgieter Afr J Tradit Complement Altern Med. (2014 ...

    African Journals Online (AJOL)

    cadewumi

    Results: A total of 43 plant species (67.4% indigenous and 32.5% exotics) from 32 ... endangered in wild habitats are conserved in home-gardens by traditional ... surveyed home-gardens are protected by South Africa's National Forest Act no.

  13. Abuelgassim and Al-Showayman Afr J Tradit Complement Altern ...

    African Journals Online (AJOL)

    AJTCAM

    C reactive protein (CRP) levels in serum were determined by the sandwich ELISA ... of diluted samples was assayed by Biuret method (Gornall et al., 1949). ... The data presented in this investigation are expressed as means ± standard error ...

  14. WANNPRES 2014 ABSTRACTS Afr J Tradit Complement Altern ...

    African Journals Online (AJOL)

    the global herbal products' market which is estimated to be US$5 trillion by 2050. .... provides a concise critical review of ethnoveterinary research and practices in ...... This work will serve to guide the users of the plant at various stages of ...

  15. Oladeji and Agbelusi, Afr J Tradit Complement Altern Med., (2017 ...

    African Journals Online (AJOL)

    Oladeji

    2017-12-29

    Dec 29, 2017 ... Local Knowledge was captured through focus group discussions with ... Sources of collecting the medicinal plant species and their mode of administration were different. Conclusion: The .... rotundifolia, Cleome ciliata.

  16. Elufioye and Awosika Afr J Tradit Complement Altern Med. (2015 ...

    African Journals Online (AJOL)

    cadewumi

    the treatment of scurvy as well as for skin care, eye care, digestion, constipation, respiratory disorders, gout, weight loss, and urinary disorders due to presence of a large amount of vitamin-C and flavonoids, both of which are class-1 antioxidants, antibiotic and disinfectants (Agrawal and. Paridhavi , 2007). Honey is used as ...

  17. Li et al., Afr J Tradit Complement Altern Med., (2017)

    African Journals Online (AJOL)

    combination with Cisplatin (CP) on SKOV-3 ovarian cancer cells. ... Treatment inhibited SKOV-3 cells by arresting of G1/G0 phase in the cell cycle, ... These drugs of natural origin can manipulate molecular targets of cell ..... One of the major aspects of platinum based therapy is resistance; mechanisms indicate decreased.

  18. Nemudzivhadi and Masoko Afr J Tradit Complement Altern Med ...

    African Journals Online (AJOL)

    cadewumi

    ANTIOXIDANT AND ANTIBACTERIAL PROPERTIES OF ZIZIPHUS MUCRONATA AND RICINUS COMMUNIS. LEAVES EXTRACTS. Vhutshilo Nemudzivhadi and Peter Masoko*. Department of Biochemistry, Microbiology and Biotechnology, University of Limpopo, Private Bag X1106, Sovenga,. 0727, South Africa.

  19. Alkali activated slag cements using waste glass as alternative activators. Rheological behaviour

    Directory of Open Access Journals (Sweden)

    Manuel Torres-Carrasco

    2015-03-01

    The findings show that AAS paste behaviour of rheology when the activator was a commercial waterglass solution or NaOH/Na2CO3 with waste glass was similar, fit the Herschel-Bulkley model. The formation of primary C-S-H gel in both cases were confirmed. However, the rheological behaviour in standard cements fit the Bingham model. The use of the waste glass may be feasible from a rheological point of view in pastes can be used.

  20. Lentiviral-mediated administration of IL-25 in the CNS induces alternative activation of microglia

    DEFF Research Database (Denmark)

    Maiorino, C; Khorooshi, R; Ruffini, F

    2013-01-01

    Interleukin-25 (IL-25) is the only anti-inflammatory cytokine of the IL-17 family, and it has been shown to be efficacious in inhibiting neuroinflammation. Known for its effects on cells of the adaptive immune system, it has been more recently described to be effective also on cells of the innate...... was partly inhibited and the CNS protected from immune-mediated damage. To our knowledge, this is the first example of M2 shift (alternative activation) induced in vivo on CNS-resident myeloid cells by gene therapy, and may constitute a promising strategy to investigate the potential role of protective...

  1. Alternate radiolabeled markers for detecting metabolic activity of Mycobacterium leprae residing in murine macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, H.K.; Hastings, R.C.

    1985-05-01

    This study demonstrated the utility of using 4% NaOH as a murine macrophage cell-solubilizing agent to discriminate between host macrophage metabolism and that of intracellular Mycobacterium leprae. A 4% concentration of NaOH had no deleterious effect on labeled mycobacteria. Thereby, alternate radiolabeled indicators of the metabolic activity of intracellular M. leprae could be experimented with. Significant incorporation of /sup 14/C-amino acid mixture, (/sup 14/C)leucine, (/sup 14/C)uridine, and carrier-free /sup 32/P was observed in cultures containing freshly extracted (''live'') strains of M. leprae as compared with control cultures containing autoclaved bacilli.

  2. Alternate radiolabeled markers for detecting metabolic activity of Mycobacterium leprae residing in murine macrophages

    International Nuclear Information System (INIS)

    Prasad, H.K.; Hastings, R.C.

    1985-01-01

    This study demonstrated the utility of using 4% NaOH as a murine macrophage cell-solubilizing agent to discriminate between host macrophage metabolism and that of intracellular Mycobacterium leprae. A 4% concentration of NaOH had no deleterious effect on labeled mycobacteria. Thereby, alternate radiolabeled indicators of the metabolic activity of intracellular M. leprae could be experimented with. Significant incorporation of 14 C-amino acid mixture, [ 14 C]leucine, [ 14 C]uridine, and carrier-free 32 P was observed in cultures containing freshly extracted (''live'') strains of M. leprae as compared with control cultures containing autoclaved bacilli

  3. The CAZyome of Phytophthora spp.: A comprehensive analysis of the gene complement coding for carbohydrate-active enzymes in species of the genus Phytophthora

    Directory of Open Access Journals (Sweden)

    Laird Emma W

    2010-09-01

    Full Text Available Abstract Background Enzymes involved in carbohydrate metabolism include Carbohydrate esterases (CE, Glycoside hydrolases (GH, Glycosyl transferases (GT, and Polysaccharide lyases (PL, commonly referred to as carbohydrate-active enzymes (CAZymes. The CE, GH, and PL superfamilies are also known as cell wall degrading enzymes (CWDE due to their role in the disintegration of the plant cell wall by bacterial and fungal pathogens. In Phytophthora infestans, penetration of the plant cells occurs through a specialized hyphal structure called appressorium; however, it is likely that members of the genus Phytophthora also use CWDE for invasive growth because hyphal forces are below the level of tensile strength exhibited by the plant cell wall. Because information regarding the frequency and distribution of CAZyme coding genes in Phytophthora is currently unknown, we have scanned the genomes of P. infestans, P. sojae, and P. ramorum for the presence of CAZyme-coding genes using a homology-based approach and compared the gene collinearity in the three genomes. In addition, we have tested the expression of several genes coding for CE in cultures grown in vitro. Results We have found that P. infestans, P. sojae and P. ramorum contain a total of 435, 379, and 310 CAZy homologs; in each genome, most homologs belong to the GH superfamily. Most GH and PL homologs code for enzymes that hydrolyze substances present in the pectin layer forming the middle lamella of the plant cells. In addition, a significant number of CE homologs catalyzing the deacetylation of compounds characteristic of the plant cell cuticle were found. In general, a high degree of gene location conservation was observed, as indicated by the presence of sequential orthologous pairs in the three genomes. Such collinearity was frequently observed among members of the GH superfamily. On the other hand, the CE and PL superfamilies showed less collinearity for some of their putative members

  4. Alternative pathways of thromboplastin-dependent activation of human factor X in plasma

    International Nuclear Information System (INIS)

    Marlar, R.A.; Griffin, J.H.

    1981-01-01

    To determine the interrelationships of the major coagulation pathways, the activation of 3H-labeled factor X in normal and various deficient human plasmas was evaluated when clotting was triggered by dilute rabbit or human thromboplastin. Various dilutions of thromboplastin and calcium were added to plasma samples containing 3H-factor X, and the time course of factor X activation was determined. At a 1/250 dilution of rabbit brain thromboplastin, the rate of factor X activation in plasmas deficient in factor VIII or factor IX was 10% of the activation rate of normal plasma or of factor XI deficient plasma. Reconstitution of the deficient plasmas with factors VIII or IX, respectively, reconstituted normal factor X activation. Similar results were obtained when various dilutions of human thromboplastin replaced the rabbit thromboplastin. From these plasma experiments, it is inferred that the dilute thromboplastin-dependent activation of factor X requires factors VII, IX, and VIII. An alternative extrinsic pathway that involves factors IX and VIII may be the physiologic extrinsic pathway and hence help to explain the consistent clinical observations of bleeding diatheses in patients deficient in factors IX or VIII

  5. Subversion of complement by hematophagous parasites

    OpenAIRE

    Schroeder, Hélène; Skelly, Patrick; Zipfel, Peter F.; Losson, Bertrand; Vanderplasschen, Alain

    2009-01-01

    The complement system is a crucial part of innate and adaptive immunity which exerts a significant evolutionary pressure on pathogens. It has selected for those pathogens, mainly micro-organisms but also parasites, that have evolved countermeasures. The characterization of how pathogens evade complement attack is a rapidly developing field of current research. In recent years, multiple complement evasion strategies have been characterized. In this review, we focus on complement escape mechani...

  6. Depression of Complement Regulatory Factors in Rat and Human Renal Grafts Is Associated with the Progress of Acute T-Cell Mediated Rejection.

    Directory of Open Access Journals (Sweden)

    Kazuaki Yamanaka

    Full Text Available The association of complement with the progression of acute T cell mediated rejection (ATCMR is not well understood. We investigated the production of complement components and the expression of complement regulatory proteins (Cregs in acute T-cell mediated rejection using rat and human renal allografts.We prepared rat allograft and syngeneic graft models of renal transplantation. The expression of Complement components and Cregs was assessed in the rat grafts using quantitative real-time PCR (qRT-PCR and immunofluorescent staining. We also administered anti-Crry and anti-CD59 antibodies to the rat allograft model. Further, we assessed the relationship between the expression of membrane cofactor protein (MCP by immunohistochemical staining in human renal grafts and their clinical course.qRT-PCR results showed that the expression of Cregs, CD59 and rodent-specific complement regulator complement receptor 1-related gene/protein-y (Crry, was diminished in the rat allograft model especially on day 5 after transplantation in comparison with the syngeneic model. In contrast, the expression of complement components and receptors: C3, C3a receptor, C5a receptor, Factor B, C9, C1q, was increased, but not the expression of C4 and C5, indicating a possible activation of the alternative pathway. When anti-Crry and anti-CD59 mAbs were administered to the allograft, the survival period for each group was shortened. In the human ATCMR cases, the group with higher MCP expression in the grafts showed improved serum creatinine levels after the ATCMR treatment as well as a better 5-year graft survival rate.We conclude that the expression of Cregs in allografts is connected with ATCMR. Our results suggest that controlling complement activation in renal grafts can be a new strategy for the treatment of ATCMR.

  7. conformational complexity of complement component C3

    NARCIS (Netherlands)

    Janssen, B.J.C.

    2007-01-01

    The complement system is an important part of the immune system and critical for the elimination of pathogens. In mammals the complement system consists of an intricate set of about 35 soluble and cell-surface plasma proteins. Central to complement is component C3, a large protein of 1,641 residues.

  8. CFTR-dependent defect in alternatively-activated macrophages in cystic fibrosis.

    Science.gov (United States)

    Tarique, Abdullah A; Sly, Peter D; Holt, Patrick G; Bosco, Anthony; Ware, Robert S; Logan, Jayden; Bell, Scott C; Wainwright, Claire E; Fantino, Emmanuelle

    2017-07-01

    The role of the macrophages in cystic fibrosis (CF) lung disease has been poorly studied. We hypothesized that alternatively activated M2 macrophages are abnormal in CF lung disease. Blood samples were collected from adults (n=13) children (n=27) with CF on admission for acute pulmonary exacerbation and when clinically stable. Monocytes were differentiated into macrophages and polarized into classical (M1) and alternatively-activated (M2) phenotypes, function determined ex-vivo and compared with healthy controls. In the absence of functional cystic fibrosis trans-membrane conductance regulator (CFTR), either naturally in patients with CF or induced with CFTR inhibitors, monocyte-derived macrophages do not respond to IL-13/IL-4, fail to polarize into M2s associated with a post-transcriptional failure to produce and express IL-13Rα1 on the macrophage surface Polarization to the M1 phenotype was unaffected. CFTR-dependent imbalance of macrophage phenotypes and functions could contribute to the exaggerated inflammatory response seen in CF lung disease. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  9. Novel alternating polymer adsorption/surface activation self-assembled film based on hydrogen bond

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yongjun; Yang Shuguang; Guan Ying; Miao Xiaopeng; Cao Weixiao; Xu Jian

    2003-08-01

    By combining hydrogen bonding layer-by-layer self-assembly and the stepwise chemisorption method, a new alternating polymer adsorption/surface activation self-assembly method was developed. First a layer of diphenylamine-4-diazonium-formaldehyde resin (diazo resin or DR) is deposited on a substrate. In the following surface activation step, the diazonium groups on the surface couple with resorcin in the outside solution. The deposition of another layer of DR is feasible due to the formation of hydrogen bond between the diazonium group of DR and the hydroxy group of the resorcin moieties. The resulting film is photosensitive. After UV irradiation, the film becomes very stable towards polar organic solvents.

  10. Sleep and alertness during alternating monophasic and polyphasic rest-activity cycles.

    Science.gov (United States)

    Porcú, S; Casagrande, M; Ferrara, M; Bellatreccia, A

    1998-07-01

    People involved in shift work often have to face altered patterns of sleep and wakefulness. This is particularly true for schedules involving night shifts and/or fragmentation of duty periods throughout the 24-hr day. In such conditions, it can be difficult to obtain satisfactory periods of sleep, and sleepiness on duty is a frequent and dangerous occurrence. The aim of this study was to evaluate sleep and wakefulness periods of subjects whose work schedule was characterized by an alternation of 2 hours of activity and 4 hours of rest (sleep allowed), repeated 4 times throughout the 24-hr day. This schedule was alternated with 24 hours off duty. Nine healthy male volunteers were monitored by means of ambulatory polysomnography while attending their 24-hr rest-activity schedule. Sleep periods were visually scored according to standard criteria. Wake periods were visually scored using both 30 s and 5 s epochs in order to reveal episodes of drowsiness and/or microsleep. Results showed that total sleep time was substantially reduced as compared to the usual 7-8 hour monophasic nocturnal sleep. Subjects did not sleep during the first rest period (11.00-15.00). Time in sleep linearly increased in the course of the 3 remaining rest periods. Normal sleep stage distribution was substantially spared only in the last rest period (3.00-7.00 a.m.). With regard to duty periods, only a few microsleeps were detected and their number did not significantly vary across the four 2-hr activity periods. In conclusion, this rest-activity schedule, despite the considerable sleep reduction, allowed maintaining good levels of vigilance as shown by the virtual absence of EEG microsleeps. Whether future research will prove that this regimen does not cause an impairment of performance, it should be a suitable strategy for the management of continuous operations.

  11. Complement activation in chromosome 13 dementias

    DEFF Research Database (Denmark)

    Rostagno, A.; Revesz, T.; Lashley, T.

    2002-01-01

    Chromosome 13 dementias, familial British dementia (FBD) and familial Danish dementia (FDD), are associated with neurodegeneration and cerebrovascular amyloidosis, with striking neuropathological similarities to Alzheimer's disease (AD). Despite the structural differences among the amyloid subunits...

  12. CipA of Acinetobacter baumannii Is a Novel Plasminogen Binding and Complement Inhibitory Protein.

    Science.gov (United States)

    Koenigs, Arno; Stahl, Julia; Averhoff, Beate; Göttig, Stephan; Wichelhaus, Thomas A; Wallich, Reinhard; Zipfel, Peter F; Kraiczy, Peter

    2016-05-01

    Acinetobacter baumannii is an emerging opportunistic pathogen, responsible for up to 10% of gram-negative, nosocomial infections. The global increase of multidrug-resistant and pan-resistant Acinetobacter isolates presents clinicians with formidable challenges. To establish a persistent infection,A. baumannii must overcome the detrimental effects of complement as the first line of defense against invading microorganisms. However, the immune evasion principles underlying serum resistance inA. baumannii remain elusive. Here, we identified a novel plasminogen-binding protein, termed CipA. Bound plasminogen, upon conversion to active plasmin, degraded fibrinogen and complement C3b and contributed to serum resistance. Furthermore, CipA directly inhibited the alternative pathway of complement in vitro, irrespective of its ability to bind plasminogen. A CipA-deficient mutant was efficiently killed by human serum and showed a defect in the penetration of endothelial monolayers, demonstrating that CipA is a novel multifunctional protein that contributes to the pathogenesis ofA. baumannii. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  13. Radioassays for quantitation of intact complement proteins C2 and B in human serum

    Energy Technology Data Exchange (ETDEWEB)

    Oglesby, T J; Ueda, A; Volanakis, J E

    1988-05-25

    Availability of polyclonal and monoclonal antibodies recognizing determinants on the major cleavage fragments of complement proteins C2 and B enabled development of sensitive radioassays which can be used to quantitate the intact proteins in human sera. Changes in C2 and B concentrations indicative of classical or alternative pathway activation, or both, were seen in normal serum after incubation with complement activators. The authors determined the normal range of C2 concentration to be 11-35 ..mu..g/ml in 32 healthy individuals, and that of protein B to be 74-286 ..mu..g/ml. Sera from patients with systemic lupus erythematosus (SLE), septic shock, infections, and following orthopedic surgery were then assayed. Mean protein B concentration was significantly higher in SLE sera and in the infected and post-operative sera, and the mean C2 concentration in the septic shock group was significantly lower than the mean of healthy individuals. Intact C2 was not detected in known C2-deficient individuals. These assays allow parallel quantitation of the structurally and functionally homologous proteins of the classical (C2) and alternative (B) pathways, which is of interest in patients with genetic and acquired hypocomplementemia. 22 refs.; 3 figs.

  14. Neutron activation analysis of alternative waste forms at the Savannah River Laboratory

    International Nuclear Information System (INIS)

    Johns, R.A.

    1981-01-01

    A remotely controlled system for neutron activation of candidate high-level waste (HLW) isolation forms was built by the Savannah River Laboratory at a Savannah River Plant reactor. With this system, samples can be irradiated for up to 24 hours and transferred through pneumatic tubing to a shielded repository unitl their activity is low enough for them to be handled in a radiobench. The principal use of the system is to support the Alternative Waste Forms Leach Testing (AWFLT) Program in which the comparative leachability of the various waste forms will be determined. The experimental method used in this work is based on neutron activation analysis techniques. Neutron irradiation of the solid waste form containing simulated HLW sludge activates elements in the sample. After suitable leaching of the solid matrix in standard solutions, the leachate and solid are assayed for gamma-emitting nuclides. From these measurements, the fraction of a specific element leached can be determined al half-lives with experimental ones, over a range of 24 orders of magnitude was obtained. This is a strong argument that the alpha decay could be considered a fission process with very high mass asymmetry and charge density asymmetry

  15. Tobacco and alcohol: complements or substitutes? ; a structural model approach

    OpenAIRE

    Tauchmann, Harald; Göhlmann, Silja; Requate, Till; Schmidt, Christoph M.

    2008-01-01

    The question of whether two drugs – namely alcohol and tobacco – are used as complements or substitutes is of crucial interest if side-effects of anti-smoking policies are considered. Numerous papers have empirically addressed this issue by estimating demand systems for alcohol and tobacco and subsequently calculating cross-price effects. However, this traditional approach often is seriously hampered by insufficient price-variation observed in survey data. We therefore suggest an alternative ...

  16. Input-output analysis of alternative policies implemented on the energy activities: An application for Catalonia

    International Nuclear Information System (INIS)

    Llop, Maria; Pie, Laia

    2008-01-01

    The aim of this paper is to analyze the economic impact of alternative policies implemented on the energy activities of the Catalan production system. Specifically, we analyze the effects of a tax on intermediate energy uses, a reduction in intermediate energy demand, and a tax on intermediate uses combined with a reduction in intermediate energy demand. The methodology involves two versions of the input-output price model: a competitive price formulation and a mark-up price formulation. The input-output price framework will make it possible to evaluate how the alternative measures modify production prices, consumption prices, private real income, and intermediate energy uses. The empirical application is for the Catalan economy and uses economic data for the year 2001. The combination of a tax on energy uses and an improvement in the energy efficiency of the production system is a measure that accomplishes both economic and environmental goals, since it has no effects on prices, it has a positive effect on private real income and, finally, energy consumption is considerably reduced. (author)

  17. Electrochemically activated water as an alternative to chlorine for decentralized disinfection

    KAUST Repository

    Ghebremichael, Kebreab A.

    2011-06-01

    Electrochemically activated (ECA) water is being extensively studied and considered as an alternative to chlorine for disinfection. Some researchers claim that ECA is by and large a chlorine solution, while others claim the presence of reactive oxygen species such as ozone and hydroxyl radicals in addition to chlorine. This study compares sodium hypochlorite (NaOCl) and ECA in terms of disinfection efficacy, trihalomethanes (THMs) formation, stability and composition. The studies were carried out under different process conditions (pH 5,7 and 9, disinfectant concentrations of 2-5 mg/L and dissolved organic carbon (DOC) concentration of 2-4 mg/L). The results indicated that in the presence of low DOC (<2 mg/L) ECA showed better disinfection efficacy for Escherichia coli inactivation, formed lower THM and had better stability compared with NaOCl at both pH 5 and 7. Stability studies of stock solutions showed that over a period of 30 days, ECA decayed by only 5% while NaOCl decayed by 37.5% at temperatures of 4 °C. In a fresh ECA of 200 mg/L chlorine, about 5.3 mg/L ozone and 36.9 mg/L ClO2 were detected. The study demonstrates that ECA could be a suitable alternative to NaOCl where decentralized production and use are required. © IWA Publishing 2011.

  18. Inhibition of the complement system by saliva of Anopheles (Nyssorhynchus) aquasalis.

    Science.gov (United States)

    Mendes-Sousa, Antonio Ferreira; Vale, Vladimir Fazito; Queiroz, Daniel Costa; Pereira-Filho, Adalberto Alves; da Silva, Naylene Carvalho Sales; Koerich, Leonardo Barbosa; Moreira, Luciano Andrade; Pereira, Marcos Horácio; Sant'Anna, Maurício Roberto; Araújo, Ricardo Nascimento; Andersen, John; Valenzuela, Jesus Gilberto; Gontijo, Nelder Figueiredo

    2018-01-01

    Anopheline mosquitoes are vectors of malaria parasites. Their saliva contains anti-hemostatic and immune-modulator molecules that favor blood feeding and parasite transmission. In this study, we describe the inhibition of the alternative pathway of the complement system (AP) by Anopheles aquasalis salivary gland extracts (SGE). According to our results, the inhibitor present in SGE acts on the initial step of the AP blocking deposition of C3b on the activation surfaces. Properdin, which is a positive regulatory molecule of the AP, binds to SGE. When SGE was treated with an excess of properdin, it was unable to inhibit the AP. Through SDS-PAGE analysis, A. aquasalis presented a salivary protein with the same molecular weight as recombinant complement inhibitors belonging to the SG7 family described in the saliva of other anopheline species. At least some SG7 proteins bind to properdin and are AP inhibitors. Searching for SG7 proteins in the A. aquasalis genome, we retrieved a salivary protein that shared an 85% identity with albicin, which is the salivary alternative pathway inhibitor from A. albimanus. This A. aquasalis sequence was also very similar (81% ID) to the SG7 protein from A. darlingi, which is also an AP inhibitor. Our results suggest that the salivary complement inhibitor from A. aquasalis is an SG7 protein that can inhibit the AP by binding to properdin and abrogating its stabilizing activity. Albicin, which is the SG7 from A. albimanus, can directly inhibit AP convertase. Given the high similarity of SG7 proteins, the SG7 from A. aquasalis may also directly inhibit AP convertase in the absence of properdin. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Reincarnation of ancient links between coagulation and complement.

    Science.gov (United States)

    Conway, E M

    2015-06-01

    Throughout evolution, organisms have developed means to contain wounds by simultaneously limiting bleeding and eliminating pathogens and damaged host cells via the recruitment of innate defense mechanisms. Disease emerges when there is unchecked activation of innate immune and/or coagulation responses. A key component of innate immunity is the complement system. Concurrent excess activation of coagulation and complement - two major blood-borne proteolytic pathways - is evident in numerous diseases, including atherosclerosis, diabetes, venous thromboembolic disease, thrombotic microangiopathies, arthritis, cancer, and infectious diseases. Delineating the cross-talk between these two cascades will uncover novel therapeutic insights. © 2015 International Society on Thrombosis and Haemostasis.

  20. Using an alternate reality game to increase physical activity and decrease obesity risk of college students.

    Science.gov (United States)

    Johnston, Jeanne D; Massey, Anne P; Marker-Hoffman, Rickie Lee

    2012-07-01

    This quasi-experimental study investigated a game intervention--specifically, an alternate reality game (ARG)--as a means to influence college students' physical activity (PA). An ARG is an interactive narrative that takes place in the real world and uses multiple media to reveal a story. Three sections of a college health course (n = 115 freshman students) were assigned either to a game group that played the ARG or to a comparison group that learned how to use exercise equipment in weekly laboratory sessions. Pre- and post-intervention measures included weight, waist circumference, body mass index (BMI), percentage body fat (PBF), and self-reported moderate physical activity (MPA) and vigorous physical activity (VPA), and PA (steps/week). A significant group x time interaction (p = .001) was detected for PA, with a significant increase in PA for the game (p students--collaborative and social, experiential and media-rich. Our results provide preliminary evidence that a game intervention can positively influence PA within the college student population. © 2012 Diabetes Technology Society.

  1. Alternative method to determine Specific Activity of (177)Lu by HPLC.

    Science.gov (United States)

    Breeman, Wouter A P; de Zanger, Rory M S; Chan, Ho Sze; de Blois, Erik

    2015-01-01

    Peptide Receptor Radionuclide Therapy (PRRT) with (177)Lu-DOTA-peptides requires (177)Lu with high specific activity (SA) and values >740 GBq (177)Lu per mg Lu to maximise the atom% of (177)Lu over total Lu. Vendors provide SA values which are based on activity and mass of the target, whereas due to "burn-up" of target, these SA values are not accurate. For a radiochemist the SA of (177)Lu is of interest prior to radiolabeling. An alternative method to determine SA was developed by HPLC, which includes a metal titration of a known amount of DOTA-peptide with a known amount of activity ((177)Lu), and a unknown amount of metal ((177+nat)Lu). Based on an HPLC separation of radiometal-DOTA-peptide and DOTA-peptide, and the concordant ratio of these components the metal content ((177+nat)Lu) can be calculated, and eventually the SA of (177)Lu can be accurately determined. These experimentally determined SA values exceeded the estimated values provided by vendors by 27 ± 16%, (range 6-73 %). The deviation of SA values for samples from the same Lu batch was <2% (n ≥ 10). the SA of (177)Lu is apparently often higher as stated by vendors in comparison to the experimentally determined actual values. For this reason, the SA of (177)Lu-DOTA-TATE and other Lu-DOTA-peptides could be increased accordingly.

  2. The role of complement receptors type 1 (CR1, CD35) and 2 (CR2, CD21) in promoting C3 fragment deposition and membrane attack complex formation on normal peripheral human B cells

    DEFF Research Database (Denmark)

    Nielsen, Claus Henrik; Pedersen, Morten Løbner; Marquart, Hanne Vibeke Hansen

    2002-01-01

    Normal human B lymphocytes are known to activate the alternative pathway (AP) of complement, leading to C3-fragment deposition and membrane attack complex (MAC) formation. The process is mediated via complement receptor type 2 (CR2, CD21), with complement receptor type 1 (CR1, CD35) playing...... a subsidiary role. In this study, we examine the relative contributions of CR1 and CR2 to the deposition of C3 fragments and MAC on B lymphocytes under circumstances where all complement pathways are operational. C3-fragment deposition and MAC formation were assessed on human peripheral B lymphocytes...... in the presence of 30% autologous serum. Blocking the CR2 ligand-binding site with monoclonal antibody (mAb) FE8 resulted in significant reduction (37.9+/-11.9%) in C3-fragment deposition, whereas MAC formation was only marginally affected (12.1+/-22.2% reduction). Blocking the CR1 binding-site resulted...

  3. A zebrafish model for uremic toxicity: role of the complement pathway.

    Science.gov (United States)

    Berman, Nathaniel; Lectura, Melisa; Thurman, Josh; Reinecke, James; Raff, Amanda C; Melamed, Michal L; Reinecke, James; Quan, Zhe; Evans, Todd; Meyer, Timothy W; Hostetter, Thomas H

    2013-01-01

    Many organic solutes accumulate in end-stage renal disease (ESRD) and some are poorly removed with urea-based prescriptions for hemodialysis. However, their toxicities have been difficult to assess. We have employed an animal model, the zebrafish embryo, to test the toxicity of uremic serum compared to control. Serum was obtained from stable ESRD patients predialysis or from normal subjects. Zebrafish embryos 24 h postfertilization were exposed to experimental media at a water:human serum ratio of 3:1. Those exposed to serum from uremic subjects had significantly reduced survival at 8 h (19 ± 18 vs. 94 ± 6%, p 50 kDa, respectively). Heating serum abrogated its toxicity. EDTA, a potent inhibitor of complement by virtue of calcium chelation, reduced the toxicity of uremic serum compared to untreated uremic serum (96 ± 5 vs. 28 ± 20% survival, p < 0.016, chelated vs. nonchelated serum, respectively). Anti-factor B, a specific inhibitor of the alternative complement pathway, reduced the toxicity of uremic serum, compared to untreated uremic serum (98 ± 6 vs. 3 ± 9% survival, p < 0.016, anti-factor B treated vs. nontreated, respectively). Uremic serum is thus more toxic to zebrafish embryos than normal serum. Furthermore, this toxicity is associated with a fraction of large size, is inactivated by heat, and is reduced by both specific and nonspecific inhibitors of complement activation. Together these data lend support to the hypothesis that at least some uremic toxicities may be mediated by complement. Copyright © 2013 S. Karger AG, Basel.

  4. Prostaglandins and complement changes in some conditions related to inflammation. [Mice

    Energy Technology Data Exchange (ETDEWEB)

    Eisen, V.; Walker, D.I.; Binysh, S.G.; Tedder, R.S.

    1977-01-01

    Exposure to ionizing radiation produces several systemic and local reactions which could be mediated by prostaglandins. Prostaglandin levels were therefore studied in blood and tissues of mice which had been exposed to x-rays. Significant increases were found in spleens after 200 to 700 R, and in lungs after 600 to 700 R. These changes were most pronounced 4 to 7 days after irradiation. Ionizing radiation promptly and potently reduced the activity of prostaglandin dehydrogenase in the spleen, whereas prostaglandin synthesis was less affected. Evidence was obtained for the activation and consumption of haemolytic complement in serum in the course of heart-lung operations involving extracorporeal circulation. Activation involved primarily the classical pathway, and only slightly the alternate pathway.

  5. Lessons learned from mice deficient in lectin complement pathway molecules

    DEFF Research Database (Denmark)

    Genster, Ninette; Takahashi, Minoru; Sekine, Hideharu

    2014-01-01

    in turn activate downstream complement components, ultimately leading to elimination of the pathogen. Mice deficient in the key molecules of lectin pathway of complement have been generated in order to build knowledge of the molecular mechanisms of the lectin pathway in health and disease. Despite......The lectin pathway of the complement system is initiated when the pattern-recognition molecules, mannose-binding lectin (MBL), ficolins or collectin-11, bind to invading pathogens or damaged host cells. This leads to activation of MBL/ficolin/collectin-11 associated serine proteases (MASPs), which...... differences in the genetic arrangements of murine and human orthologues of lectin pathway molecules, the knockout mice have proven to be valuable models to explore the effect of deficiency states in humans. In addition, new insight and unexpected findings on the diverse roles of lectin pathway molecules...

  6. Septicaemia models using Streptococcus pneumoniae and Listeria monocytogenes: understanding the role of complement properdin.

    Science.gov (United States)

    Dupont, Aline; Mohamed, Fatima; Salehen, Nur'Ain; Glenn, Sarah; Francescut, Lorenza; Adib, Rozita; Byrne, Simon; Brewin, Hannah; Elliott, Irina; Richards, Luke; Dimitrova, Petya; Schwaeble, Wilhelm; Ivanovska, Nina; Kadioglu, Aras; Machado, Lee R; Andrew, Peter W; Stover, Cordula

    2014-08-01

    Streptococcus pneumoniae and Listeria monocytogenes, pathogens which can cause severe infectious disease in human, were used to infect properdin-deficient and wildtype mice. The aim was to deduce a role for properdin, positive regulator of the alternative pathway of complement activation, by comparing and contrasting the immune response of the two genotypes in vivo. We show that properdin-deficient and wildtype mice mounted antipneumococcal serotype-specific IgM antibodies, which were protective. Properdin-deficient mice, however, had increased survival in the model of streptococcal pneumonia and sepsis. Low activity of the classical pathway of complement and modulation of FcγR2b expression appear to be pathogenically involved. In listeriosis, however, properdin-deficient mice had reduced survival and a dendritic cell population that was impaired in maturation and activity. In vitro analyses of splenocytes and bone marrow-derived myeloid cells support the view that the opposing outcomes of properdin-deficient and wildtype mice in these two infection models is likely to be due to a skewing of macrophage activity to an M2 phenotype in the properdin-deficient mice. The phenotypes observed thus appear to reflect the extent to which M2- or M1-polarised macrophages are involved in the immune responses to S. pneumoniae and L. monocytogenes. We conclude that properdin controls the strength of immune responses by affecting humoral as well as cellular phenotypes during acute bacterial infection and ensuing inflammation.

  7. Masturbation and Partnered Sex: Substitutes or Complements?

    Science.gov (United States)

    Regnerus, Mark; Price, Joseph; Gordon, David

    2017-10-01

    Drawing upon a large, recent probability sample of American adults ages 18-60 (7648 men and 8090 women), we explored the association between sexual frequency and masturbation, evaluating the evidence for whether masturbation compensates for unavailable sex, complements (or augments) existing paired sexual activity, or bears little association with it. We found evidence supporting a compensatory relationship between masturbation and sexual frequency for men, and a complementary one among women, but each association was both modest and contingent on how content participants were with their self-reported frequency of sex. Among men and women, both partnered status and their sexual contentment were more obvious predictors of masturbation than was recent frequency of sex. We conclude that both hypotheses as commonly evaluated suffer from failing to account for the pivotal role of subjective sexual contentment in predicting masturbation.

  8. Is complement good, bad, or both? New functions of the complement factors associated with inflammation mechanisms in the central nervous system.

    Science.gov (United States)

    Tahtouh, Muriel; Croq, Françoise; Lefebvre, Christophe; Pestel, Joël

    2009-09-01

    The complement system is well known as an enzyme cascade that helps to defend against infections. Indeed, this ancestral system bridges innate and adaptive immunity. Its implication in diseases of the central nervous system (CNS), has led to an increased number of studies. Complement activation in the CNS has been generally considered to contribute to tissue damage. However, recent studies suggest that complement may be neuroprotective, and can participate in maintenance and repair of the adult brain. Here, we will review this dual role of complement proteins and some of their functional interactions with part of the chemokine and cytokine network associated with the protection of CNS integrity.

  9. Complement in the Initiation and Evolution of Rheumatoid Arthritis

    Science.gov (United States)

    Holers, V. Michael; Banda, Nirmal K.

    2018-01-01

    The complement system is a major component of the immune system and plays a central role in many protective immune processes, including circulating immune complex processing and clearance, recognition of foreign antigens, modulation of humoral and cellular immunity, removal of apoptotic and dead cells, and engagement of injury resolving and tissue regeneration processes. In stark contrast to these beneficial roles, however, inadequately controlled complement activation underlies the pathogenesis of human inflammatory and autoimmune diseases, including rheumatoid arthritis (RA) where the cartilage, bone, and synovium are targeted. Recent studies of this disease have demonstrated that the autoimmune response evolves over time in an asymptomatic preclinical phase that is associated with mucosal inflammation. Notably, experimental models of this disease have demonstrated that each of the three major complement activation pathways plays an important role in recognition of injured joint tissue, although the lectin and amplification pathways exhibit particularly impactful roles in the initiation and amplification of damage. Herein, we review the complement system and focus on its multi-factorial role in human patients with RA and experimental murine models. This understanding will be important to the successful integration of the emerging complement therapeutics pipeline into clinical care for patients with RA. PMID:29892280

  10. Complement and hyper acute rejection

    Directory of Open Access Journals (Sweden)

    Al-Rabia Mohammed

    2009-01-01

    Full Text Available Organ transplantation has been a major development in clinical medicine but its success has been marred by the immune system′s capacity to respond to "non-self" cells and tissues. A full molecular understanding of this mechanism and the myriad triggers for immune rejection is yet to be elucidated. Consequently, immunosuppressive drugs remain the mainstay of post-transplant ma-nagement; however, these interventions have side effects such as increased incidence of cancer, post-transplant lymphoproliferative disorders, susceptibility to infection if not managed appro-priately and the inconvenience to the patient of lifelong treatment. Novel therapeutic approaches based on molecular understanding of immunological processes are thus needed in this field. The notion that factors influencing successful transplants might be of use as therapeutic approaches is both scientifically and medically appealing. Recent developments in the understanding of successful transplants are expected to provide new opportunities for safer transplantation. This article reviews the present understanding of the molecular basis of rejection and the role of complement in this process as well as the possibility of generating "intelligent" therapy that better target crucial components of hyper-acute rejections.

  11. Subversion of complement by hematophagous parasites.

    Science.gov (United States)

    Schroeder, Hélène; Skelly, Patrick J; Zipfel, Peter F; Losson, Bertrand; Vanderplasschen, Alain

    2009-01-01

    The complement system is a crucial part of innate and adaptive immunity which exerts a significant evolutionary pressure on pathogens. It has selected for those pathogens, mainly microorganisms but also parasites, that have evolved countermeasures. The characterization of how pathogens evade complement attack is a rapidly developing field of current research. In recent years, multiple complement evasion strategies have been characterized. In this review, we focus on complement escape mechanisms expressed by hematophagous parasites, a heterogeneous group of metazoan parasites that share the property of ingesting the whole blood of their host. Complement inhibition is crucial for parasite survival within the host tissue or to facilitate blood feeding. Finally, complement inhibition by hematophagous parasites may also contribute to their success as pathogen vectors.

  12. AKT1, LKB1, and YAP1 revealed as MYC interactors with NanoLuc-based protein-fragment complementation assay. | Office of Cancer Genomics

    Science.gov (United States)

    The c-Myc (MYC) transcription factor is a major cancer driver and a well-validated therapeutic target. However, directly targeting MYC has been challenging. Thus, identifying proteins that interact with and regulate MYC may provide alternative strategies to inhibit its oncogenic activity. Here we report the development of a NanoLuc®-based protein-fragment complementation assay (NanoPCA) and mapping of the MYC protein interaction hub in live mammalian cells.

  13. Active parenting or Solomon’s justice?
    Alternating residence in Sweden for children with separated parents

    Directory of Open Access Journals (Sweden)

    Anna Singer

    2008-06-01

    Full Text Available Alternating residence for children with separated parents has become increasingly popular in Sweden over the last few decades. In this article, a brief background to the use of alternating residence in Sweden will be provided. Relevant legislation will be described and some of the apparent problems in connection to this kind of living arrangement will also be discussed. It is estimated that approximately one out of every five children with separated parents today are living alternately with both parents. The high frequency of alternating residence can probably be explained, to a great extent, by determined legislative work to ensure that joint custody is the main rule for separated parents. Joint custody after separation encourages parents to take a more active part in the child’s life. Alternating residence can be seen as the optimal way to ensure that a child is provided natural and stress-free contact with both parents in the different events of everyday life that is not possible when the child lives with one parent. However, there are also problems related to alternating residence that need to be addressed. The possibility for the courts to decide on alternating residence against the will of one of the parents appears to have little justification considering that one of the prerequisites for this form of living arrangement is that it is beneficial for children if their parents can co-operate. There are also other aspects of the regulation of alternating residence that need to be improved, in particular questions concerning the child maintenance. Different aspects of the public social security system for children with separated parents also need to be adjusted to provide just and fair solutions for children with alternating residence. Finally, since alternating residence is motivated by a desire to protect the best interests of the child, further research clarifying the experiences of children with alternating residence needs to be carried

  14. Alarin but not its alternative-splicing form, GALP (Galanin-like peptide) has antimicrobial activity

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Akihiro, E-mail: a-wada@nagasaki-u.ac.jp [Department of Bacteriology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan); Wong, Pooi-Fong [Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur (Malaysia); Hojo, Hironobu [Department of Applied Biochemistry, Institute of Glycoscience, Tokai University, Kanagawa 2591292 (Japan); Hasegawa, Makoto [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Shiga 5260829 (Japan); Ichinose, Akitoyo [Electron Microscopy Shop Central Laboratory, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan); Llanes, Rafael [Institute Pedro Kouri, Havana (Cuba); Kubo, Yoshinao [Division of Cytokine Signaling, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 8528523 (Japan); Senba, Masachika [Department of Pathology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan); Ichinose, Yoshio [Kenya Research Station, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan)

    2013-05-03

    Highlights: • Alarin inhibits the growth of E. coli but not S. aureus. • Alarin’s potency is comparable to LL-37 in inhibiting the growth of E. coli. • Alarin can cause bacterial membrane blebbing. • Alalin does not induce hemolysis on erythrocytes. -- Abstract: Alarin is an alternative-splicing form of GALP (galanin-like peptide). It shares only 5 conserved amino acids at the N-terminal region with GALP which is involved in a diverse range of normal brain functions. This study seeks to investigate whether alarin has additional functions due to its differences from GALP. Here, we have shown using a radial diffusion assay that alarin but not GALP inhibited the growth of Escherichia coli (strain ML-35). The conserved N-terminal region, however, remained essential for the antimicrobial activity of alarin as truncated peptides showed reduced killing effect. Moreover, alarin inhibited the growth of E. coli in a similar potency as human cathelicidin LL-37, a well-studied antimicrobial peptide. Electron microscopy further showed that alarin induced bacterial membrane blebbing but unlike LL-37, it did not cause hemolysis of erythrocytes. In addition, alarin is only active against the gram-negative bacteria, E. coli but not the gram-positive bacteria, Staphylococcus aureus. Thus, these data suggest that alarin has potentials as an antimicrobial and should be considered for the development in human therapeutics.

  15. Complement drives glucosylceramide accumulation and tissue inflammation in Gaucher disease.

    Science.gov (United States)

    Pandey, Manoj K; Burrow, Thomas A; Rani, Reena; Martin, Lisa J; Witte, David; Setchell, Kenneth D; Mckay, Mary A; Magnusen, Albert F; Zhang, Wujuan; Liou, Benjamin; Köhl, Jörg; Grabowski, Gregory A

    2017-03-02

    Gaucher disease is caused by mutations in GBA1, which encodes the lysosomal enzyme glucocerebrosidase (GCase). GBA1 mutations drive extensive accumulation of glucosylceramide (GC) in multiple innate and adaptive immune cells in the spleen, liver, lung and bone marrow, often leading to chronic inflammation. The mechanisms that connect excess GC to tissue inflammation remain unknown. Here we show that activation of complement C5a and C5a receptor 1 (C5aR1) controls GC accumulation and the inflammatory response in experimental and clinical Gaucher disease. Marked local and systemic complement activation occurred in GCase-deficient mice or after pharmacological inhibition of GCase and was associated with GC storage, tissue inflammation and proinflammatory cytokine production. Whereas all GCase-inhibited mice died within 4-5 weeks, mice deficient in both GCase and C5aR1, and wild-type mice in which GCase and C5aR were pharmacologically inhibited, were protected from these adverse effects and consequently survived. In mice and humans, GCase deficiency was associated with strong formation of complement-activating GC-specific IgG autoantibodies, leading to complement activation and C5a generation. Subsequent C5aR1 activation controlled UDP-glucose ceramide glucosyltransferase production, thereby tipping the balance between GC formation and degradation. Thus, extensive GC storage induces complement-activating IgG autoantibodies that drive a pathway of C5a generation and C5aR1 activation that fuels a cycle of cellular GC accumulation, innate and adaptive immune cell recruitment and activation in Gaucher disease. As enzyme replacement and substrate reduction therapies are expensive and still associated with inflammation, increased risk of cancer and Parkinson disease, targeting C5aR1 may serve as a treatment option for patients with Gaucher disease and, possibly, other lysosomal storage diseases.

  16. Complement anaphylatoxins as immune regulators in cancer

    OpenAIRE

    Sayegh, Eli T; Bloch, Orin; Parsa, Andrew T

    2014-01-01

    The role of the complement system in innate immunity is well characterized. However, a recent body of research implicates the complement anaphylatoxins C3a and C5a as insidious propagators of tumor growth and progression. It is now recognized that certain tumors elaborate C3a and C5a and that complement, as a mediator of chronic inflammation and regulator of immune function, may in fact foster rather than defend against tumor growth. A putative mechanism for this function is complement-mediat...

  17. Complement anaphylatoxins as immune regulators in cancer.

    Science.gov (United States)

    Sayegh, Eli T; Bloch, Orin; Parsa, Andrew T

    2014-08-01

    The role of the complement system in innate immunity is well characterized. However, a recent body of research implicates the complement anaphylatoxins C3a and C5a as insidious propagators of tumor growth and progression. It is now recognized that certain tumors elaborate C3a and C5a and that complement, as a mediator of chronic inflammation and regulator of immune function, may in fact foster rather than defend against tumor growth. A putative mechanism for this function is complement-mediated suppression of immune effector cells responsible for immunosurveillance within the tumor microenvironment. This paradigm accords with models of immune dysregulation, such as autoimmunity and infectious disease, which have defined a pathophysiological role for abnormal complement signaling. Several types of immune cells express the cognate receptors for the complement anaphylatoxins, C3aR and C5aR, and demonstrate functional modulation in response to complement stimulation. In turn, impairment of antitumor immunity has been intimately tied to tumor progression in animal models of cancer. In this article, the literature was systematically reviewed to identify studies that have characterized the effects of the complement anaphylatoxins on the composition and function of immune cells within the tumor microenvironment. The search identified six studies based upon models of lymphoma and ovarian, cervical, lung, breast, and mammary cancer, which collectively support the paradigm of complement as an immune regulator in the tumor microenvironment. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  18. Trypanosoma cruzi Evades the Complement System as an Efficient Strategy to Survive in the Mammalian Host: The Specific Roles of Host/Parasite Molecules and Trypanosoma cruzi Calreticulin

    Directory of Open Access Journals (Sweden)

    Galia Ramírez-Toloza

    2017-09-01

    Full Text Available American Trypanosomiasis is an important neglected reemerging tropical parasitism, infecting about 8 million people worldwide. Its agent, Trypanosoma cruzi, exhibits multiple mechanisms to evade the host immune response and infect host cells. An important immune evasion strategy of T. cruzi infective stages is its capacity to inhibit the complement system activation on the parasite surface, avoiding opsonizing, immune stimulating and lytic effects. Epimastigotes, the non-infective form of the parasite, present in triatomine arthropod vectors, are highly susceptible to complement-mediated lysis while trypomastigotes, the infective form, present in host bloodstream, are resistant. Thus T. cruzi susceptibility to complement varies depending on the parasite stage (amastigote, trypomastigotes or epimastigote and on the T. cruzi strain. To avoid complement-mediated lysis, T. cruzi trypomastigotes express on the parasite surface a variety of complement regulatory proteins, such as glycoprotein 58/68 (gp58/68, T. cruzi complement regulatory protein (TcCRP, trypomastigote decay-accelerating factor (T-DAF, C2 receptor inhibitor trispanning (CRIT and T. cruzi calreticulin (TcCRT. Alternatively, or concomitantly, the parasite captures components with complement regulatory activity from the host bloodstream, such as factor H (FH and plasma membrane-derived vesicles (PMVs. All these proteins inhibit different steps of the classical (CP, alternative (AP or lectin pathways (LP. Thus, TcCRP inhibits the CP C3 convertase assembling, gp58/68 inhibits the AP C3 convertase, T-DAF interferes with the CP and AP convertases assembling, TcCRT inhibits the CP and LP, CRIT confers ability to resist the CP and LP, FH is used by trypomastigotes to inhibit the AP convertases and PMVs inhibit the CP and LP C3 convertases. Many of these proteins have similar molecular inhibitory mechanisms. Our laboratory has contributed to elucidate the role of TcCRT in the host

  19. Conditioned medium from alternatively activated macrophages induce mesangial cell apoptosis via the effect of Fas

    International Nuclear Information System (INIS)

    Huang, Yuan; Luo, Fangjun; Li, Hui; Jiang, Tao; Zhang, Nong

    2013-01-01

    During inflammation in the glomerulus, the proliferation of myofiroblast-like mesangial cells is commonly associated with the pathological process. Macrophages play an important role in regulating the growth of resident mesangial cells in the glomeruli. Alternatively activated macrophage (M2 macrophage) is a subset of macrophages induced by IL-13/IL-4, which is shown to play a repair role in glomerulonephritis. Prompted by studies of development, we performed bone marrow derived macrophage and rat mesangial cell co-culture study. Conditioned medium from IL-4 primed M2 macrophages induced rat mesangial cell apoptosis. The pro-apoptotic effect of M2 macrophages was demonstrated by condensed nuclei stained with Hoechst 33258, increased apoptosis rates by flow cytometry analysis and enhanced caspase-3 activation by western blot. Fas protein was up-regulated in rat mesangial cells, and its neutralizing antibody ZB4 partly inhibited M2 macrophage-induced apoptosis. The up-regulated arginase-1 expression in M2 macrophage also contributed to this apoptotic effect. These results indicated that the process of apoptosis triggered by conditioned medium from M2 macrophages, at least is partly conducted through Fas in rat mesangial cells. Our findings provide compelling evidence that M2 macrophages control the growth of mesangial cells in renal inflammatory conditions. - Highlights: • Conditioned-medium from M2 macrophages induces rat mesangial cell (MsC) apoptosis. • M2 macrophage conditioned medium exerts its pro-apoptotic effects via Fas ligand. • Arginase-1 activity in M2 macrophages plays a role in inducing apoptosis in rat MsC

  20. Conditioned medium from alternatively activated macrophages induce mesangial cell apoptosis via the effect of Fas

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yuan; Luo, Fangjun; Li, Hui; Jiang, Tao; Zhang, Nong, E-mail: nzhang@fudan.edu.cn

    2013-11-15

    During inflammation in the glomerulus, the proliferation of myofiroblast-like mesangial cells is commonly associated with the pathological process. Macrophages play an important role in regulating the growth of resident mesangial cells in the glomeruli. Alternatively activated macrophage (M2 macrophage) is a subset of macrophages induced by IL-13/IL-4, which is shown to play a repair role in glomerulonephritis. Prompted by studies of development, we performed bone marrow derived macrophage and rat mesangial cell co-culture study. Conditioned medium from IL-4 primed M2 macrophages induced rat mesangial cell apoptosis. The pro-apoptotic effect of M2 macrophages was demonstrated by condensed nuclei stained with Hoechst 33258, increased apoptosis rates by flow cytometry analysis and enhanced caspase-3 activation by western blot. Fas protein was up-regulated in rat mesangial cells, and its neutralizing antibody ZB4 partly inhibited M2 macrophage-induced apoptosis. The up-regulated arginase-1 expression in M2 macrophage also contributed to this apoptotic effect. These results indicated that the process of apoptosis triggered by conditioned medium from M2 macrophages, at least is partly conducted through Fas in rat mesangial cells. Our findings provide compelling evidence that M2 macrophages control the growth of mesangial cells in renal inflammatory conditions. - Highlights: • Conditioned-medium from M2 macrophages induces rat mesangial cell (MsC) apoptosis. • M2 macrophage conditioned medium exerts its pro-apoptotic effects via Fas ligand. • Arginase-1 activity in M2 macrophages plays a role in inducing apoptosis in rat MsC.

  1. Human neutrophil peptides and complement factor Bb in pathogenesis of acquired thrombotic thrombocytopenic purpura.

    Science.gov (United States)

    Cao, Wenjing; Pham, Huy P; Williams, Lance A; McDaniel, Jenny; Siniard, Rance C; Lorenz, Robin G; Marques, Marisa B; Zheng, X Long

    2016-11-01

    Acquired thrombotic thrombocytopenic purpura is primarily caused by the deficiency of plasma ADAMTS13 activity resulting from autoantibodies against ADAMTS13. However, ADAMTS13 deficiency alone is often not sufficient to cause acute thrombotic thrombocytopenic purpura. Infections or systemic inflammation may precede acute bursts of the disease, but the underlying mechanisms are not fully understood. Herein, 52 patients with acquired autoimmune thrombotic thrombocytopenic purpura and 30 blood donor controls were recruited for the study. The plasma levels of human neutrophil peptides 1-3 and complement activation fragments (i.e. Bb, iC3b, C4d, and sC5b-9) were determined by enzyme-linked immunosorbent assays. Univariate analyses were performed to determine the correlation between each biomarker and clinical outcomes. We found that the plasma levels of human neutrophil peptides 1-3 and Bb in patients with acute thrombotic thrombocytopenic purpura were significantly higher than those in the control (Ppurpura patients and the control. We conclude that innate immunity, i.e. neutrophil and complement activation via the alternative pathway, may play a role in the pathogenesis of acute autoimmune thrombotic thrombocytopenic purpura, and a therapy targeted at these pathways may be considered in a subset of these patients. Copyright© Ferrata Storti Foundation.

  2. The role of complement in CD4⁺ T cell homeostasis and effector functions.

    Science.gov (United States)

    Kolev, Martin; Le Friec, Gaëlle; Kemper, Claudia

    2013-02-01

    The complement system is among the evolutionary oldest 'players' of the immune system. It was discovered in 1896 by Jules Bordet as a heat-labile fraction of the serum responsible for the opsonisation and subsequent killing of bacteria. The decades between the 1920s and 1990s then marked the discovery and biochemical characterization of the proteins comprising the complement system. Today, complement is defined as a complex system consisting of more than 30 membrane-bound and soluble plasma proteins, which are activated in a cascade-like manner, very similarly to the caspase proteases and blood coagulation systems. Complement is engrained in the immunologist's mind as a serum-effective, quintessential part of innate immunity, vitally required for the detection and removal of pathogens or other dangerous entities. Three decades ago, this rather confined definition was challenged and then refined when it was shown that complement participates vitally in the induction and regulation of B cell responses, thus adaptive immunity. Similarly, research work published in more recent years supports an equally important role for the complement system in shaping T cell responses. Today, we are again facing paradigm shifts in the field: complement is actively involved in the negative control of T cell effector immune responses, and thus, by definition in immune homeostasis. Further, while serum complement activity is without doubt fundamental in the defence against invading pathogens, local immune cell-derived production of complement emerges as key mediator of complement's impact on adaptive immune responses. And finally, the impact of complement on metabolic pathways and the crosstalk between complement and other immune effector systems is likely more extensive than previously anticipated and is fertile ground for future discoveries. In this review, we will discuss these emerging new roles of complement, with a focus on Th1 cell biology. Copyright © 2013 Elsevier Ltd. All

  3. The complement system and its role in the pathogenesis of periodontitis

    DEFF Research Database (Denmark)

    Damgaard, Christian; Holmstrup, Palle; Van Dyke, Thomas E.

    2015-01-01

    Periodontitis is a highly prevalent inflammatory disease in tooth supporting tissues, induced by bacteria growing in a biofilm on tooth surfaces. Components of the complement system are present in the periodontal tissue and the system is activated in periodontitis. Continuous complement activation...... and modulation by bacteria within the biofilm in periodontal pockets, however, may enhance local tissue destruction, providing the biofilm with both essential nutrients and space to grow. A more profound understanding of the mechanisms involved in complement-derived tissue degradation may facilitate...... with an emphasis on interaction of complement with bacteria from periodontitis-associated biofilm....

  4. How regional non-proliferation arrangements complement international verification

    International Nuclear Information System (INIS)

    Carlson, J.

    1999-01-01

    This presentation focuses on international verification in the form of IAEA Safeguards, and discusses the relationship between IAEA safeguards and the relevant regional arrangements, both the existing and the future. For most States the political commitment against acquisition of nuclear weapons has been carefully reached and strongly held. Their observance of treaty commitments does not depend on the deterrent effect of verification activities. Safeguards serve to assist States who recognise it is in their own interest to demonstrate their compliance to others. Thus safeguards are a vital confidence building measure in their own right, as well as being a major complement to the broader range of international confidence building measures. Safeguards can both complement other confidence building measures and in turn be complemented by them. Within consideration of how it could work it is useful to consider briefly current developments of IAEA safeguards, i.e. existing regional arrangements and nuclear weapon free zones

  5. Role of complement in porphyrin-induced photosensitivity

    International Nuclear Information System (INIS)

    Lim, H.W.; Gigli, I.

    1981-01-01

    Addition of porphyrins to sera of guinea pigs in vitro, followed by irradiation with 405 nm light, resulted in dose-dependent inhibitions of hemolytic activity of complement. With guinea pig as an animal model, we also found that systemically administered porphyrins, followed by irradiation with 405 nm light, resulted in dose-dependent inhibition of CH50 in vivo. The erythrocytes from porphyrin-treated guinea pigs showed an increased susceptibility to hemolysis induced by 405 nm irradiation in vitro. Clinical changes in these animals were limited to light-exposed areas and consisted of erythema, crusting, and delayed growth of hair. Histologically, dermal edema, dilation of blood vessels, and infiltration of mononuclear and polymorphonuclear cells were observed. Guinea pigs irradiated with ultraviolet-B developed erythema, but had no alteration of their complement profiles. It is suggested that complement products may play a specific role in the pathogenesis of the cutaneous lesions of some porphyrias

  6. Structure and function of complement protein C1q and its role in the development of autoimmune diseases

    Directory of Open Access Journals (Sweden)

    Katarzyna Smykał-Jankowiak

    2009-09-01

    Full Text Available Complement plays an important role in the immune system. Three different pathways of complement activation are known: the classical, alternative, and lectin dependent. They involve more than 30 serum peptides. C1q is the first subcomponent of the classical pathway of complement activation. It is composed of three types of chains, A, B, and C, which form a molecule containing 18 peptides. Each of the chains has a short amino-terminal region followed by a collagen-like region (playing a role in the activation of C1r2C1s2 and a carboxy-terminal head, which binds to immune complexes. Recent studies have shown a great number of ligands for C1q, including aggregated IgG, IgM, human T-cell lymphotropic virus-I (HTLV-I, gp21 peptide, human immunodeficiency virus-1 (HIV-1 gp21 peptide, β-amyloid, fragments of bacterial walls, apoptotic cells, and many others. However, the role of C1q is not only associated with complement activation. It also helps in the removal of immune complexes and necrotic cells, stimulates the production of some cytokines, and modulates the function of lymphocytes. Complete C1q deficiency is a rare genetic disorder. The C1q gene is located on the short arm of chromosome 1. So far, only a few mutations in C1q gene have been reported. The presence of these mutations is strongly associated with recurrent bacterial infections and the development of systemic lupus erythematosus (SLE. Recent clinical studies point to the significance of anti-C1q antibodies in the diagnosis and assessment of lupus nephritis activity.

  7. Complement pathways and meningococcal disease : diagnostic aspects

    DEFF Research Database (Denmark)

    Sjöholm, A G; Truedsson, L; Jensenius, Jens Christian

    2001-01-01

    Complement is an immunological effector system that bridges innate and acquired immunity in several ways. There is a striking association between susceptibility to meningococcal disease and various forms of complement deficiency (1,2). In defense against bacterial infection, the most important fu...

  8. Alternate particle removal technologies for the Airborne Activity Confinement System at the Savannah River Site

    International Nuclear Information System (INIS)

    Brockmann, J.E.; Adkins, C.L.J.; Gelbard, F.

    1991-09-01

    This report presents a review of the filtration technologies available for the removal of particulate material from a gas stream. It was undertaken to identify alternate filtration technologies that may be employed in the Airborne Activity Confinement System (AACS) at the Savannah River Plant. This report is organized into six sections: (1) a discussion of the aerosol source term and its definition, (2) a short discussion of particle and gaseous contaminant removal mechanisms, (3) a brief overview of particle removal technologies, (4) a discussion of the existing AACS and its potential shortcomings, (5) an enumeration of issues to be addressed in upgrading the AACS, and, (6) a detailed discussion of the identified technologies. The purpose of this report is to identity available options to the existing particle removal system. This system is in continuous operation during routine operation of the reactor. As will be seen, there are a number of options and the selection of any technology or combination of technologies will depend on the design aerosol source term (yet to be appropriately defined) as well as the flow requirements and configuration. This report does not select a specific technology. It focuses on particulate removal and qualitatively on the removal of radio-iodine and mist elimination. Candidate technologies have been selected from industrial and nuclear gas cleaning applications

  9. Intermittent fasting promotes adipose thermogenesis and metabolic homeostasis via VEGF-mediated alternative activation of macrophage.

    Science.gov (United States)

    Kim, Kyoung-Han; Kim, Yun Hye; Son, Joe Eun; Lee, Ju Hee; Kim, Sarah; Choe, Min Seon; Moon, Joon Ho; Zhong, Jian; Fu, Kiya; Lenglin, Florine; Yoo, Jeong-Ah; Bilan, Philip J; Klip, Amira; Nagy, Andras; Kim, Jae-Ryong; Park, Jin Gyoon; Hussein, Samer Mi; Doh, Kyung-Oh; Hui, Chi-Chung; Sung, Hoon-Ki

    2017-11-01

    Intermittent fasting (IF), a periodic energy restriction, has been shown to provide health benefits equivalent to prolonged fasting or caloric restriction. However, our understanding of the underlying mechanisms of IF-mediated metabolic benefits is limited. Here we show that isocaloric IF improves metabolic homeostasis against diet-induced obesity and metabolic dysfunction primarily through adipose thermogenesis in mice. IF-induced metabolic benefits require fasting-mediated increases of vascular endothelial growth factor (VEGF) expression in white adipose tissue (WAT). Furthermore, periodic adipose-VEGF overexpression could recapitulate the metabolic improvement of IF in non-fasted animals. Importantly, fasting and adipose-VEGF induce alternative activation of adipose macrophage, which is critical for thermogenesis. Human adipose gene analysis further revealed a positive correlation of adipose VEGF-M2 macrophage-WAT browning axis. The present study uncovers the molecular mechanism of IF-mediated metabolic benefit and suggests that isocaloric IF can be a preventive and therapeutic approach against obesity and metabolic disorders.

  10. Cooking with Active Oxygen and Solid Alkali: A Promising Alternative Approach for Lignocellulosic Biorefineries.

    Science.gov (United States)

    Jiang, Yetao; Zeng, Xianhai; Luque, Rafael; Tang, Xing; Sun, Yong; Lei, Tingzhou; Liu, Shijie; Lin, Lu

    2017-10-23

    Lignocellulosic biomass, a matrix of biopolymers including cellulose, hemicellulose, and lignin, has gathered increasing attention in recent years for the production of chemicals, fuels, and materials through biorefinery processes owing to its renewability and availability. The fractionation of lignocellulose is considered to be the fundamental step to establish an economical and sustainable lignocellulosic biorefinery. In this Minireview, we summarize a newly developed oxygen delignification for lignocellulose fractionation called cooking with active oxygen and solid alkali (CAOSA), which can fractionate lignocellulose into its constituents and maintain its processable form. In the CAOSA approach, environmentally friendly chemicals are applied instead of undesirable chemicals such as strong alkalis and sulfides. Notably, the alkali recovery for this process promises to be relatively simple and does not require causticizing or sintering. These features make the CAOSA process an alternative for both lignocellulose fractionation and biomass pretreatment. The advantages and challenges of CAOSA are also discussed to provide a comprehensive perspective with respect to existing strategies. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. "Petit suisse" cheese from kefir: an alternative dessert with microorganisms of probiotic activity

    Directory of Open Access Journals (Sweden)

    Thanise Sabrina Souza Santos

    2012-09-01

    Full Text Available "Petit Suisse" is a creamy cheese. Kefir is a symbiotic mixture of lactic acid bacteria and yeasts with probiotic activity including immunomodulation and balance of intestinal microflora. The present study aims to develop "Petit Suisse" cheese from kefir. Kefir grains were grown in pasteurized cow milk, and after the separation of kefir the serum was discarded and the "Petit Suisse" cheese was prepared using strawberry, mangaba, herbs, and dried tomatoes. The acceptance of the different preparations was evaluated using a nine-point hedonic scale followed by ANOVA. The sweet and salty products were compared by the Student's t-test. Purchase intent was evaluated by the means test and frequency distribution. All products were well accepted by the judges. The product was characterized by low yield, but it can be prepared at home at low cost. The nutritional composition analyses and the variety of flavors as well as the range of age of the judges are alternatives for further studies.

  12. Intermittent fasting promotes adipose thermogenesis and metabolic homeostasis via VEGF-mediated alternative activation of macrophage

    Science.gov (United States)

    Kim, Kyoung-Han; Kim, Yun Hye; Son, Joe Eun; Lee, Ju Hee; Kim, Sarah; Choe, Min Seon; Moon, Joon Ho; Zhong, Jian; Fu, Kiya; Lenglin, Florine; Yoo, Jeong-Ah; Bilan, Philip J; Klip, Amira; Nagy, Andras; Kim, Jae-Ryong; Park, Jin Gyoon; Hussein, Samer MI; Doh, Kyung-Oh; Hui, Chi-chung; Sung, Hoon-Ki

    2017-01-01

    Intermittent fasting (IF), a periodic energy restriction, has been shown to provide health benefits equivalent to prolonged fasting or caloric restriction. However, our understanding of the underlying mechanisms of IF-mediated metabolic benefits is limited. Here we show that isocaloric IF improves metabolic homeostasis against diet-induced obesity and metabolic dysfunction primarily through adipose thermogenesis in mice. IF-induced metabolic benefits require fasting-mediated increases of vascular endothelial growth factor (VEGF) expression in white adipose tissue (WAT). Furthermore, periodic adipose-VEGF overexpression could recapitulate the metabolic improvement of IF in non-fasted animals. Importantly, fasting and adipose-VEGF induce alternative activation of adipose macrophage, which is critical for thermogenesis. Human adipose gene analysis further revealed a positive correlation of adipose VEGF-M2 macrophage-WAT browning axis. The present study uncovers the molecular mechanism of IF-mediated metabolic benefit and suggests that isocaloric IF can be a preventive and therapeutic approach against obesity and metabolic disorders. PMID:29039412

  13. Neutron activation analysis of alternative phosphate rocks used in animal nutrition

    International Nuclear Information System (INIS)

    Canella, Artur A.; Ferreira, Walter M.

    2005-01-01

    Since 1980's, Bovine Sponghiform Encephalophaty has insidiously created a fierce battleground between farmers, scientists, environmentalists and consumers. The use of meat and bone meals is currently prohibited in ruminant feeds throughout the world. Some inorganic sources offer the combination of high phosphorus content and acceptable animal digestibility make them options as supplemental phosphorus, for instance phosphate rocks, general term applied to minerals valued chiefly for their phosphorus content. However, phosphate rocks are long been known containing hazardous elements, make them sometimes unsuitable for animal nutrition. Neutron Activation Analysis has been supportive to the mineral evaluation of alternative phosphate rocks. This evaluation is subject of on-going doctoral thesis which has been carried-out by the main author. The NAA method has been very efficient due to its highly sensitive and multi-elemental nature. In this paper results of Vanadium content from three different phosphate rocks are presented. Their values have been pointed out that Brazilian phosphate rocks present hazardous elements at the same levels of phosphate rocks from some countries of Africa, North America and Middle East, data from our study (Brazilian data) and FAO - Food and Agriculture Organization (others countries). (author)

  14. Transcriptomic analysis of human polarized macrophages: more than one role of alternative activation?

    Directory of Open Access Journals (Sweden)

    Eleonora Derlindati

    Full Text Available Macrophages are a heterogeneous cell population which in response to the cytokine milieu polarize in either classically activated macrophages (M1 or alternatively activated macrophages (M2. This plasticity makes macrophages essential in regulating inflammation, immune response and tissue remodeling and a novel therapeutic target in inflammatory diseases such as atherosclerosis. The aim of the study was to describe the transcriptomic profiles of differently polarized human macrophages to generate new hypotheses on the biological function of the different macrophage subtypes.Polarization of circulating monocytes/macrophages of blood donors was induced in vitro by IFN-γ and LPS (M1, by IL-4 (M2a, and by IL-10 (M2c. Unstimulated cells (RM served as time controls. Gene expression profile of M1, M2a, M2c and RM was assessed at 6, 12 and 24h after polarization with Whole Human Genome Agilent Microarray technique. When compared to RM, M1 significantly upregulated pathways involved in immunity and inflammation, whereas M2a did the opposite. Conversely, decreased and increased expression of mitochondrial metabolism, consistent with insulin resistant and insulin sensitive patterns, was seen in M1 and M2a, respectively. The time sequence in the expression of some pathways appeared to have some specific bearing on M1 function. Finally, canonical and non-canonical Wnt genes and gene groups, promoting inflammation and tissue remodeling, were upregulated in M2a compared to RM.Our data in in vitro polarized human macrophages: 1. confirm and extend known inflammatory and anti-inflammatory gene expression patterns; 2. demonstrate changes in mitochondrial metabolism associated to insulin resistance and insulin sensitivity in M1 and M2a, respectively; 3. highlight the potential relevance of gene expression timing in M1 function; 4. unveil enhanced expression of Wnt pathways in M2a suggesting a potential dual (pro-inflammatory and anti-inflammatory role of M2a in

  15. Excess circulating alternatively activated myeloid (M2 cells accelerate ALS progression while inhibiting experimental autoimmune encephalomyelitis.

    Directory of Open Access Journals (Sweden)

    Ilan Vaknin

    Full Text Available Circulating immune cells including autoreactive T cells and monocytes have been documented as key players in maintaining, protecting and repairing the central nervous system (CNS in health and disease. Here, we hypothesized that neurodegenerative diseases might be associated, similarly to tumors, with increased levels of circulating peripheral myeloid derived suppressor cells (MDSCs, representing a subset of suppressor cells that often expand under pathological conditions and inhibit possible recruitment of helper T cells needed for fighting off the disease.We tested this working hypothesis in amyotrophic lateral sclerosis (ALS and its mouse model, which are characterized by a rapid progression once clinical symptoms are evident. Adaptive transfer of alternatively activated myeloid (M2 cells, which homed to the spleen and exhibited immune suppressive activity in G93A mutant superoxide dismutase-1 (mSOD1 mice at a stage before emergence of disease symptoms, resulted in earlier appearance of disease symptoms and shorter life expectancy. The same protocol mitigated the inflammation-induced disease model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE, which requires circulating T cells for disease induction. Analysis of whole peripheral blood samples obtained from 28 patients suffering from sporadic ALS (sALS, revealed a two-fold increase in the percentage of circulating MDSCs (LIN(-/LowHLA-DR(-CD33(+ compared to controls.Taken together, these results emphasize the distinct requirements for fighting the inflammatory neurodegenerative disease, multiple sclerosis, and the neurodegenerative disease, ALS, though both share a local inflammatory component. Moreover, the increased levels of circulating MDSCs in ALS patients indicates the operation of systemic mechanisms that might lead to an impairment of T cell reactivity needed to overcome the disease conditions within the CNS. This high level of suppressive immune cells might

  16. Taenia crassiceps Antigens Control Experimental Type 1 Diabetes by Inducing Alternatively Activated Macrophages

    Science.gov (United States)

    Espinoza-Jiménez, Arlett; De Haro, Roberto

    2017-01-01

    Type 1 diabetes (T1D) is an autoimmune disease caused by the selective destruction of the pancreatic β-cells, causing inability to produce insulin. Proinflammatory cytokines such as IL-1β, IL-6, TNF-α, IFN-γ, IL-12, IL-17, and NO can be released by CD4 and CD8+ lymphocytes as well as by classically activated macrophages (CAMϕs), which are important in the development of T1D. Helminth infections have been shown to prevent T1D, mainly through Th2-biased responses and increased recruitment of regulatory cell populations. Previously, we have shown that Taenia crassiceps infection in mice significantly reduces hyperglycemia, insulitis, and the incidence of T1D. In this study, we determined whether T. crassiceps-derived products such as soluble (TcS) or excreted/secreted (TcES) antigens might have a beneficial influence on the development of experimental T1D. Treatment with different doses before or after induction of T1D was analyzed. Mice that were pretreated with TcS were unable to develop T1D, whereas those receiving TcES early after T1D induction displayed significantly reduced insulitis and hyperglycemia along with increased recruitment of alternatively activated macrophages (AAMϕs) and myeloid-derived suppressor cells (MDSCs). Finally, we examined the modulatory role of AAMϕs on T1D by depleting macrophages with clodronate-loaded liposomes, demonstrating that AAMϕs are key cells in T1D regulation. PMID:29249872

  17. Television and Our Children. A Report of the Activities of the Alternatives in Children's Broadcasting Project.

    Science.gov (United States)

    Mainse, David

    Two major objectives of the Alternatives in Children's Broadcasting Project were to determine the extent of the influence of violence in children's television and to determine if children's interest in prosocial programming makes it a viable alternative to violence programming. Both adults and 8-10 year old children were surveyed about their…

  18. Critical Evaluation of Animal Alternative Tests for the Identification of Endocrine Active Substances

    Science.gov (United States)

    A significant amount of research is currently targeted to evaluate alternative test methods that may reduce, refine, or replace the use of animals, while ensuring human and environmental health and safety. It is important that the information gained from the alternative tests pr...

  19. Critical Evaluation of Animal Alternative Tests for the Identification of Endocrine Active Substances, oral presentation

    Science.gov (United States)

    In the past 20 years, considerable progress in animal alternatives accompanied by advances in the toxicological sciences and new emphases on aquatic vertebrates has appeared. A significant amount of current research is targeted to evaluate alternative test methods that may reduce...

  20. In vitro complement activation, adherence to red blood cells and induction of mononuclear cell cytokine production by four strains of Aggregatibacter actinomycetemcomitans with different fimbriation and expression of leukotoxin

    DEFF Research Database (Denmark)

    Damgaard, C.; Reinholdt, J.; Palarasah, Y.

    2017-01-01

    BACKGROUND AND OBJECTIVE: The periodontal pathogen Aggregatibacter actinomycetemcomitans has been proposed as pro-atherogenic, and complement-mediated adherence to red blood cells (RBCs) may facilitate its systemic spread. We investigated the ability of four strains of A. actinomycetemcomitans wi...