Search results for "immunoglobulin G"
showing 10 items of 308 documents
Evidence for the presence of autoantibodies to the collagen-like portion of C1q in systemic lupus erythematosus.
1988
We investigated the connection between the C1q solid-phase binding assay (C1q SPBA) and double-stranded DNA antibodies, and analyzed the immune complex material in systemic lupus erythematosus (SLE) sera. Comparison with a new monoclonal assay for C1q-bearing immune complexes (the 242G3 assay) revealed that the immune complexes in SLE bind specifically to solid-phase C1q, and not to fluid-phase C1q. The C1q solid-phase binding activity sedimented as 7S IgG, was insensitive to DNase treatment, and could be selectively absorbed by C1q-coupled beads and by bovine serum albumin-anti-bovine serum albumin C1q beads, but not by DNA. Thus, antibodies to double-stranded DNA do not interfere in the C…
Dense Bodies of Human Cytomegalovirus Induce both Humoral and Cellular Immune Responses in the Absence of Viral Gene Expression
2000
ABSTRACTInfection of fibroblast cell cultures with human cytomegalovirus (HCMV) leads to the production of significant amounts of defective enveloped particles, termed dense bodies (DB). These noninfectious structures contain major antigenic determinants which are responsible for induction of both the humoral and the cellular immune response against HCMV. We tested the hypothesis that, by virtue of their unique antigenic and structural properties, DB could induce a significant immune response in the absence of infectious virus. Mice were immunized with gradient-purified DB, which were either left untreated or subjected to sequential rounds of sonication and freeze-thawing to prevent cellula…
Comparative Antitumor Effect of Preventive versus Therapeutic Vaccines Employing B16 Melanoma Cells Genetically Modified to Express GM-CSF and B7.2 i…
2012
Cancer vaccines have always been a subject of gene therapy research. One of the most successful approaches has been working with genetically modified tumor cells. In this study, we describe our approach to achieving an immune response against a murine melanoma model, employing B16 tumor cells expressing GM-CSF and B7.2. Wild B16 cells were injected in C57BL6 mice to cause the tumor. Irradiated B16 cells transfected with GM-CSF, B7.2, or both, were processed as a preventive and therapeutic vaccination. Tumor volumes were measured and survival curves were obtained. Blood samples were taken from mice, and IgGs of each treatment group were also measured. The regulatory T cells (Treg) o…
Molecular Characterization of Virus-induced Autoantibody Responses
2004
Here we present a comprehensive molecular mapping of virus-induced autoimmune B cell responses obtained by serological identification of antigens by recombinant expression cloning analysis. Immunoscreening of cDNA expression libraries of various organs (lung, liver, and spleen) using sera from mice infected with cytopathic (vaccinia virus [VV]) or noncytopathic (lymphocytic choriomeningitis virus [LCMV]) viruses revealed a broad specificity of the elicited autoantibody response. Interestingly, the majority of the identified autoantigens have been previously described as autoantigens in humans. We found that induction of virus-induced autoantibodies of the immunoglobulin G class largely depe…
Impact of a Three Amino Acid Deletion in the CH2 Domain of Murine IgG1 on Fc-Associated Effector Functions
2008
Abstract Four murine IgG subclasses display markedly different Fc-associated effector functions because of their differential binding to three activating IgG Fc receptors (FcγRI, FcγRIII, and FcγRIV) and C1q. Previous analysis of IgG subclass switch variants of 34-3C anti-RBC monoclonal autoantibodies revealed that the IgG1 subclass, which binds only to FcγRIII and fails to activate complement, displayed the poorest pathogenic potential. This could be related to the presence of a three amino acid deletion at positions 233–235 in the CH2 domain uniquely found in this subclass. To address this question, IgG1 insertion and IgG2b deletion mutants at positions 233–235 of 34-3C anti-RBC Abs were …
Diagnosis of Non-Celiac Gluten Sensitivity (NCGS): The Salerno Experts’ Criteria
2015
Non-Celiac Gluten Sensitivity (NCGS) is a syndrome characterized by intestinal and extra-intestinal symptoms related to the ingestion of gluten-containing food, in subjects that are not affected by either celiac disease or wheat allergy. Given the lack of a NCGS biomarker, there is the need for standardizing the procedure leading to the diagnosis confirmation. In this paper we report experts' recommendations on how the diagnostic protocol should be performed for the confirmation of NCGS. A full diagnostic procedure should assess the clinical response to the gluten-free diet (GFD) and measure the effect of a gluten challenge after a period of treatment with the GFD. The clinical evaluation i…
Gluten-Free Diet Reduces Symptoms, Particularly Diarrhea, in Patients With Irritable Bowel Syndrome and Antigliadin IgG
2021
Background & Aims Many patients with irritable bowel syndrome (IBS) perceive that their symptoms are triggered by wheat-containing foods. We assessed symptoms and gastrointestinal transit before and after a gluten-free diet (GFD) in unselected patients with IBS and investigated biomarkers associated with symptoms. Methods We performed a prospective study of 50 patients with IBS (ROME III, all subtypes), with and without serologic reactivity to gluten (antigliadin IgG and IgA), and 25 healthy subjects (controls) at a university hospital in Hamilton, Ontario, Canada, between 2012 and 2016. Gastrointestinal transit, gut symptoms, anxiety, depression, somatization, dietary habits, and microbiot…
Autoantibody depletion ameliorates disease in murine experimental autoimmune encephalomyelitis.
2013
Much data support a role for central nervous system antigen-specific antibodies in the pathogenesis of multiple sclerosis (MS). The effects of inducing a decrease in (auto)antibody levels on MS or experimental autoimmune encephalomyelitis (EAE) through specific blockade of FcRn, however, remain unexplored. We recently developed engineered antibodies that lower endogenous IgG levels by competing for binding to FcRn. These Abdegs ("antibodies that enhance IgG degradation") can be used to directly assess the effect of decreased antibody levels in inflammatory diseases. In the current study, we show that Abdeg delivery ameliorates disease in an EAE model that is antibody dependent. Abdegs could…
Analytical Performance and Validation of a Bioassay for Thyroid-Blocking Antibodies
2016
A cell-based bioassay for the measurement of thyroid blocking autoantibodies (TBAb) has been recently reported. The analytical performance and validation of this bioassay is assessed and described.Chinese hamster ovary cells expressing a chimeric thyrotropin receptor were treated with bovine (b) TSH and different concentrations of an immunoglobulin G (IgG) monoclonal human TBAb (K1-70). TBAb was measured as a function of luciferase activity relative to bTSH alone and expressed as percent inhibition. Results obtained in the chimeric cell line were compared with those of a wild-type cell line. Analytical performance studies were subsequently performed with the chimeric cell line only.Immunode…
Antibodies to proteinase 3 increase adhesion of neutrophils to human endothelial cells
1993
SUMMARY The detection of anti-neutrophil cytoplasmic antibodies (ANCA), especially those with specificity for proteinase 3, is important in the diagnosis and in monitoring disease activity of Wegener's granulomatosis and related vasculitides. An ubiquitous feature of all ANCA-associated acute vascular injury is lytic necrosis. Adhesion of neutrophils to endothelium is a fundamental early step of the inflammatory response. Recently we were able to show that ANCA recognize their target antigen (proteinase 3) translocated into the membrane of human endothelial cells. The aim of this study was to investigate the effect of ANCA on the adhesion of neutrophils to human endothelial cells. Incubatio…