Search results for "Complement System Proteins"
showing 10 items of 56 documents
Inflammatory Response Mechanisms of the Dentine–Pulp Complex and the Periapical Tissues
2021
The macroscopic and microscopic anatomy of the oral cavity is complex and unique in the human body. Soft-tissue structures are in close interaction with mineralized bone, but also dentine, cementum and enamel of our teeth. These are exposed to intense mechanical and chemical stress as well as to dense microbiologic colonization. Teeth are susceptible to damage, most commonly to caries, where microorganisms from the oral cavity degrade the mineralized tissues of enamel and dentine and invade the soft connective tissue at the core, the dental pulp. However, the pulp is well-equipped to sense and fend off bacteria and their products and mounts various and intricate defense mechanisms. The fron…
Bioactive potential of silica coatings and its effect on the adhesion of proteins to titanium implants
2018
There is an ever-increasing need to develop dental implants with ideal characteristics to achieve specific and desired biological response in the scope of improve the healing process post-implantation. Following that premise, enhancing and optimizing titanium implants through superficial treatments, like silica sol-gel hybrid coatings, are regarded as a route of future research in this area. These coatings change the physicochemical properties of the implant, ultimately affecting its biological characteristics. Sandblasted acid-etched titanium (SAE-Ti) and a silica hybrid sol-gel coating (35M35G30T) applied onto the Ti substrate were examined. The results of in vitro and in vivo tests and t…
Association between Leptin and Complement in Hepatitis C Patients with Viral Clearance: Homeostasis of Metabolism and Immunity
2016
Background The association between leptin and complement in hepatitis C virus (HCV) infection remains unknown. Methods A prospective study was conducted including 474 (250 genotype 1, 224 genotype 2) consecutive chronic hepatitis C (CHC) patients who had completed an anti-HCV therapy course and undergone pre-therapy and 24-week post-therapy assessments of interferon λ3-rs12979860 and HCV RNA/genotypes, anthropometric measurements, metabolic and liver profiles, and complement component 3 (C3), C4, and leptin levels. Results Of the 474 patients, 395 had a sustained virological response (SVR). Pre-therapy leptin levels did not differ between patients with and without an SVR. Univariate and mul…
CD38-Specific Biparatopic Heavy Chain Antibodies Display Potent Complement-Dependent Cytotoxicity Against Multiple Myeloma Cells
2018
CD38 is overexpressed by multiple myeloma cells and has emerged as a target for therapeutic antibodies. Nanobodies are soluble single domain antibody fragments derived from the VHH variable domain of heavy chain antibodies naturally occurring in camelids. We previously identified distinct llama nanobodies that recognize three non-overlapping epitopes of the extracellular domain of CD38. Here, we fused these VHH domains to the hinge, CH2, and CH3 domains of human IgG1, yielding highly soluble chimeric llama/human heavy chain antibodies (hcAbs). We analyzed the capacity of these hcAbs to mediate complement-dependent cytotoxicity (CDC) to CD38-expressing human multiple myeloma and Burkitt lymp…
Immune-mediated necrotizing myopathy is characterized by a specific Th1-M1 polarized immune profile.
2012
Immune-mediated necrotizing myopathy (IMNM) is considered one of the idiopathic inflammatory myopathies, comprising dermatomyositis, polymyositis, and inclusion body myositis. The heterogeneous group of necrotizing myopathies shows a varying amount of necrotic muscle fibers, myophagocytosis, and a sparse inflammatory infiltrate. The underlying immune response in necrotizing myopathy has not yet been addressed in detail. Affected muscle tissue, obtained from 16 patients with IMNM, was analyzed compared with eight non-IMNM (nIMNM) tissues. Inflammatory cells were characterized by IHC, and immune mediators were assessed by quantitative real-time PCR. We demonstrate that immune- and non–immune-…
Synthesis of complement by macrophages and modulation of their functions through complement activation.
1983
During the last decade considerable progress has been made to characterize intimate functional links between macrophages, a major cellular component of immunoinflammatory responses, and the complement system representing the major humoral mediator of inflammation. Macrophages of various species and tissue sites have been shown to synthesize and release most of the complement components providing these cells with their own \ldpericellular\rd complement system. Circumstantial evidence for the assembly of both classical and alternative pathway convertases has been adduced. An intricate network of feedback loops involving endogenous and extrinsic factors operates to adjust complement production…
Anaphylatoxin-like molecules generated during complement activation induce a dramatic enhancement of particle uptake in rainbow trout phagocytes.
2004
Here we have identified a serum fraction containing approximately 8-kDa molecules with an unexpected capacity to greatly enhance particle uptake in trout head kidney leukocytes (HKLs). This approximately 8-kDa particle-uptake enhancing fraction (PUEF-8) was purified from complement-activated serum by gel filtration chromatography. Mass spectrometric analysis and reactivity of anti-trout C3-1 and C4 antibodies, indicated the presence of C3a, C4a and C5a molecules in PUEF-8. Using a newly developed flow cytometric assay that measures the capacity of cells to ingest fluorescent beads, we showed that PUEF-8 induced a striking enhancement (344+/-50% higher than the PBS control value) in the numb…
Ability of the T cell-replacing polyanion dextran sulfate to trigger the alternate pathway of complement activation.
1973
Dextran sulfate (DS) consumed C3 in C4 deficient guinea pig serum. This temperature-dependent reaction required Mg++ ions and could therefore be blocked by EDTA. Isolated C3 was not influenced by DS, but serum factors were required for C3 consumption. The C3 proactivator as well as C3 were converted to their activated state by DS in guinea pig and human serum, as revealed by immunoelectrophoretical analysis. DS generated anaphylatoxin activity in serum. It is concluded that DS activates C3 via the alternate pathway of complement activation. This potency of the polyanion might serve as a tentative explanation for its T cell-replacing effect in an antibody-forming system, which was reported b…
Role of C-reactive protein in atherogenesis: can the apolipoprotein E knockout mouse provide the answer?
2005
Objective—Human C-reactive protein (CRP) was reported to accelerate atherosclerotic lesion development in male but not in female apolipoprotein E (apoE) knockout mice. Here, mice expressing rabbit CRP (rbCRP) were crossbred onto apoE knockout animals, and the effect on atherogenesis was studied.Methods and Results—Hemolytic complement activity could not be detected in apoE knockout mice. Furthermore, in contrast to human complement, neither rabbit nor human CRP complexed to modified low-density lipoprotein–activated murine complement. At 52 weeks, rbCRP levels were similar in male and female transgenic animals. Serum cholesterol levels were equivalent in female animals irrespective of rbCRP…
Isolation and characterization of a complement-activating lipid extracted from human atherosclerotic lesions.
1990
The major characteristics of human atherosclerotic lesions are similar to those of a chronic inflammatory reaction, namely fibrosis, mesenchymal cell proliferation, the presence of resident macrophages, and cell necrosis. Atherosclerosis exhibits in addition the feature of lipid (mainly cholesterol) accumulation. The results of the present report demonstrate that a specific cholesterol-containing lipid particle present in human atherosclerotic lesions activates the complement system to completion. Thus, lipid could represent a stimulatory factor for the inflammatory reaction, whose underlying mechanistic basis may be, at least in part, complement activation. The complement-activating lipid …