- MeSH
- Complement Activation * physiology immunology drug effects MeSH
- Complement Activating Enzymes MeSH
- Complement C4 MeSH
- Complement C1 MeSH
- Complement C2 MeSH
- Complement C3 MeSH
- Plasma physiology drug effects MeSH
- Humans MeSH
- Fibrinolysin * therapeutic use drug effects MeSH
- Statistics as Topic MeSH
- Streptokinase * administration & dosage therapeutic use MeSH
- In Vitro Techniques methods utilization MeSH
- Check Tag
- Humans MeSH
Non-specific protein adsorption (fouling) triggers a number of deleterious events in the application of biomaterials. Antifouling polymer brushes successfully suppress fouling, however for some coatings an extremely high variability of fouling for different donors remains unexplained. The authors report that in the case of poly(2-hydroxyethyl methacrylate) (poly(HEMA)) this variability is due to the complement system activation that causes massive acceleration in the fouling kinetics of blood plasma. Using plasma from various donors, the fouling kinetics on poly(HEMA) is analyzed and correlated with proteins identified in the deposits on the surface and with the biochemical compositions of the plasma. The presence of complement components in fouling deposits and concentrations of C3a in different plasmas indicate that the alternative complement pathway plays a significant role in the fouling on poly(HEMA) through the "tick-over" mechanism of spontaneous C3 activation. The generated C3b binds to the poly(HEMA) surface and amplifies complement activation locally. Heat-inactivated plasma prevents accelerated fouling kinetics, confirming the central role of complement activation. The results highlight the need to take into account the variability between individuals when assessing interactions between biomaterials and blood plasma, as well as the importance of the mechanistic insight that can be gained from protein identification.
Dialyser bioincompatibility is an important factor contributing to complications of hemodialysis with well known systemic consequences. Here we studied the local processes that occur on dialysis membranes by eluting proteins adsorbed to the polysulfone dialyser membranes of 5 patients after 3 consecutive routine maintenance hemodialysis sessions. At the end of each procedure, a plasma sample was also collected. These eluates and their accompanying plasma samples were separated by 2-dimensional gel electrophoresis; all proteins that were present in all patients were analyzed by tandem mass spectrometry; and a ratio of the relative spot intensity of the eluate to plasma was calculated. Of 153 proteins detected, 84 were found in all patients, 57 of which were successfully identified by mass spectrometry as 38 components of 23 unique proteins. In 10 spots the relative eluate intensity differed significantly from that in the plasma, implying preferential adsorption. These proteins included ficolin-2, clusterin, complement C3c fragment, and apolipoprotein A1. Our finding of a selective binding of ficolin-2 to polysulfone membranes suggests a possible role of the lectin complement pathway in blood-dialyser interactions.
- MeSH
- Adsorption MeSH
- Apolipoprotein A-I MeSH
- Renal Dialysis instrumentation adverse effects MeSH
- Mass Spectrometry MeSH
- Clusterin MeSH
- Complement C3c MeSH
- Complement System Proteins analysis metabolism MeSH
- Lectins MeSH
- Middle Aged MeSH
- Humans MeSH
- Membranes, Artificial MeSH
- Polymers adverse effects MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Sulfones adverse effects MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND: Idiopathic inflammatory myopathies (IIM) are a group of autoimmune diseases characterised by myositis-related autoantibodies plus infiltration of leucocytes into muscles and/or the skin, leading to the destruction of blood vessels and muscle fibres, chronic weakness and fatigue. While complement-mediated destruction of capillary endothelia is implicated in paediatric and adult dermatomyositis, the complex diversity of complement C4 in IIM pathology was unknown. METHODS: We elucidated the gene copy number (GCN) variations of total C4, C4A and C4B, long and short genes in 1644 Caucasian patients with IIM, plus 3526 matched healthy controls using real-time PCR or Southern blot analyses. Plasma complement levels were determined by single radial immunodiffusion. RESULTS: The large study populations helped establish the distribution patterns of various C4 GCN groups. Low GCNs of C4T (C4T=2+3) and C4A deficiency (C4A=0+1) were strongly correlated with increased risk of IIM with OR equalled to 2.58 (2.28-2.91), p=5.0×10-53 for C4T, and 2.82 (2.48-3.21), p=7.0×10-57 for C4A deficiency. Contingency and regression analyses showed that among patients with C4A deficiency, the presence of HLA-DR3 became insignificant as a risk factor in IIM except for inclusion body myositis (IBM), by which 98.2% had HLA-DR3 with an OR of 11.02 (1.44-84.4). Intragroup analyses of patients with IIM for C4 protein levels and IIM-related autoantibodies showed that those with anti-Jo-1 or with anti-PM/Scl had significantly lower C4 plasma concentrations than those without these autoantibodies. CONCLUSIONS: C4A deficiency is relevant in dermatomyositis, HLA-DRB1*03 is important in IBM and both C4A deficiency and HLA-DRB1*03 contribute interactively to risk of polymyositis.
- MeSH
- Autoantibodies genetics MeSH
- Dermatomyositis * MeSH
- Child MeSH
- Adult MeSH
- Genetic Predisposition to Disease MeSH
- HLA-DR3 Antigen genetics MeSH
- HLA-DRB1 Chains genetics MeSH
- Complement C4 MeSH
- Complement C4a genetics MeSH
- Humans MeSH
- Myositis * MeSH
- Risk Factors MeSH
- DNA Copy Number Variations MeSH
- Check Tag
- Child MeSH
- Adult MeSH
- Humans MeSH
- Publication type
- Journal Article MeSH
Komplementový systém je klíčovou složkou vrozené imunity. Skládá se z 50 plazmatických a membránových proteinů, které tvoří tři odlišné, ale překrývající se dráhy aktivace, stejně jako společnou terminální lytickou kaskádu a síť regulátorů a receptorů. Poruchy komplementu se mohou podílet na vzniku imunodeficiencí, autoimunit, malignit, infekčních onemocnění a na chorobách spojených s dysregulací komplementu. Striktní dodržování pravidel preanalytické fáze vyšetření je zásadní pro laboratorní diagnostiku. Pro komplexní posouzení funkce a zapojení komplementu do imunopatologických procesů, musíme testovat celou paletu vyšetření (od funkčních testů, vyšetření jednotlivých složek komplementu, až po genetickou analýzu).
The complement system is a key component of innate immunity. It consists of 50 plasma and membrane proteins that form three distinct but overlapping pathways of activation, as well as a common terminal lytic cascade and a network of regulators and receptors. Complement disorders may contribute to immunodeficiencies, autoimmunity, malignancies, infectious diseases, and diseases associated with complement dysregulation. Strict adherence to the rules of the preanalytical phase of the examination is essential for laboratory diagnosis. To comprehensively assess the function and involvement of complement in immunopathological processes, we need to perform a whole range of investigations (from functional tests, examination of individual complement components, to genetic analysis).
- MeSH
- Atypical Hemolytic Uremic Syndrome diagnosis genetics MeSH
- Complement System Proteins MeSH
- Humans MeSH
- Complement Hemolytic Activity Assay * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
PURPOSE: dialysis-induced inflammatory response including leukocyte and complement activation is considered a significant cofactor of chronic morbidity in long-term hemodialysis (HD) patients. The aim of this study was to provide better insight into its molecular background. EXPERIMENTAL DESIGN: in 16 patients, basic biocompatibility markers, i.e. leukocyte counts and C5a levels, were monitored during HD on a polysulfone membrane. Proteins adsorbed to dialyzers were eluted and separated by 2-DE. Selected proteins were identified by MS; ficolin-2 plasma levels were assessed. Data are given as medians (quartile ranges). RESULTS: in total, 7.2 (34.7) mg proteins were retrieved from dialyzer eluates and were resolved into 217 protein spots. The proteins most enriched in eluates (and hence selectively adsorbed) were those involved in complement activation (C3c, ficolin-2, mannan-binding lectin serine proteases, properdin) and cell adhesion (actin, caldesmon, tropomyosin, vitronectin, vinculin). A significant decrease of plasma ficolin-2 (41% [4.7], p<0.001) was evidenced during one HD session, associated with leukopenia (r=0.73, p=0.001) and C5a production (r=-0.62, p=0.01) at 15 min. CONCLUSIONS AND CLINICAL RELEVANCE: ficolin-2 adsorption to polysulfone dialyzer initiates the lectin pathway of complement activation, mediates dialysis-induced leukopenia, and results in a significant depletion of ficolin-2, an essential component of innate immunity.
- MeSH
- Adsorption MeSH
- Renal Dialysis instrumentation methods MeSH
- Complement Pathway, Mannose-Binding Lectin MeSH
- Lectins chemistry metabolism MeSH
- Humans MeSH
- Membranes, Artificial MeSH
- Polymers chemistry metabolism MeSH
- Proteome analysis MeSH
- Gene Expression Profiling MeSH
- Sulfones chemistry metabolism MeSH
- Inflammation immunology metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The role of complement has been demonstrated in experimental models of neuromyelitis optica (NMO), however, only few studies have analysed complement components longitudinally in NMO patients. We measured serum or plasma concentrations of anti-C1q antibodies and complement split products C3a and C4a and soluble C5b-9 in patients with NMO, multiple sclerosis and healthy controls. NMO patients had higher levels of C3a and anti-C1q antibodies than healthy controls. C3a levels correlated with disease activity, neurological disability and aquaporin-4 IgG in NMO patients suggesting a role of the alternative pathway of complement in the pathogenesis of NMO and supporting the strategy of therapeutic complement inhibition.
- MeSH
- Complement Activation immunology MeSH
- Aquaporin 4 immunology MeSH
- Autoantibodies blood immunology MeSH
- Adult MeSH
- Immunoglobulin G blood immunology MeSH
- Complement C1q immunology metabolism MeSH
- Complement C3a immunology metabolism MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Follow-Up Studies MeSH
- Neuromyelitis Optica immunology MeSH
- Prospective Studies MeSH
- Multiple Sclerosis, Relapsing-Remitting immunology MeSH
- Aged MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
In birds, spectrum of egg white proteins deposited into the egg during its formation are thought to be essential maternal effects. Particularly, egg white lysozyme (LSM), exhibiting great between and within species variability, is considered to be essential for developing avian embryos due to its physiological, antimicrobial, and innate immune defense functions. However, there have been few studies investigating effects of LSM on early post-hatching phenotype, despite its broad physiological and protective role during embryogenesis. Here, we test how experimentally increased concentrations of egg white LSM affect hatchability in Japanese quail (Coturnix japonica) and chick phenotype immediately after hatching (particularly body weight, tarsus length, plasma LSM concentration, and plasma complement activity). Chicks from eggs with increased LSM concentration displayed reduced tarsus length compared to chicks from control eggs while hatchability, body weight and plasma LSM concentration were unaffected. It is worth noting that no effect of increased in ovo lysozyme on eggs hatchability could be related to pathogen-free environment during artificial incubation of experimental eggs causing minimal pressure on embryo viability. While tangible in vivo mechanisms during avian embryogenesis remain to be tested, our study is the first to document experimentally that egg white LSM appears to have growth-regulation role during embryo development, with possible underlying phenotypic consequences in the early post-hatching period in precocial birds.
- MeSH
- Coturnix anatomy & histology embryology MeSH
- Embryonic Development MeSH
- Phenotype MeSH
- Complement System Proteins metabolism MeSH
- Muramidase blood MeSH
- Ovum enzymology MeSH
- Tarsus, Animal anatomy & histology MeSH
- Body Weight MeSH
- Egg White chemistry MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Serine peptidases are involved in many physiological processes including digestion, haemostasis and complement cascade. Parasites regulate activities of host serine peptidases to their own benefit, employing various inhibitors, many of which belong to the Kunitz-type protein family. In this study, we confirmed the presence of potential anticoagulants in protein extracts of the haematophagous monogenean Eudiplozoon nipponicum which parasitizes the common carp. We then focused on a Kunitz protein (EnKT1) discovered in the E. nipponicum transcriptome, which structurally resembles textilinin-1, an antihemorrhagic snake venom factor from Pseudonaja textilis. The protein was recombinantly expressed, purified and biochemically characterised. The recombinant EnKT1 did inhibit in vitro activity of Factor Xa of the coagulation cascade, but exhibited a higher activity against plasmin and plasma kallikrein, which participate in fibrinolysis, production of kinins, and complement activation. Anti-coagulation properties of EnKT1 based on the inhibition of Factor Xa were confirmed by thromboelastography, but no effect on fibrinolysis was observed. Moreover, we discovered that EnKT1 significantly impairs the function of fish complement, possibly by inhibiting plasmin or Factor Xa which can act as a C3 and C5 convertase. We localised Enkt1 transcripts and protein within haematin digestive cells of the parasite by RNA in situ hybridisation and immunohistochemistry, respectively. Based on these results, we suggest that the secretory Kunitz protein of E. nipponicum has a dual function. In particular, it impairs both haemostasis and complement activation in vitro, and thus might facilitate digestion of a host's blood and protect a parasite's gastrodermis from damage by the complement. This study presents, to our knowledge, the first characterisation of a Kunitz protein from monogeneans and the first example of a parasite Kunitz inhibitor that impairs the function of the complement.
- MeSH
- Antifibrinolytic Agents chemistry immunology MeSH
- Anticoagulants chemistry immunology MeSH
- Factor Xa immunology MeSH
- Hemostasis * MeSH
- Trematode Infections blood immunology parasitology veterinary MeSH
- Enzyme Inhibitors chemistry immunology MeSH
- Factor Xa Inhibitors chemistry immunology MeSH
- Host-Parasite Interactions MeSH
- Carps blood immunology parasitology MeSH
- Complement System Proteins immunology MeSH
- Fish Diseases blood immunology parasitology MeSH
- Fibrinolysin immunology MeSH
- Plasma Kallikrein antagonists & inhibitors immunology MeSH
- Helminth Proteins chemistry genetics immunology MeSH
- Amino Acid Sequence MeSH
- Sequence Alignment MeSH
- Trematoda chemistry genetics immunology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
