IgG

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of IgG

  • anti-cyp2e1 igg
  • anti-dsg3 igg
  • anti-human igg
  • human igg
  • mouse igg
  • patient igg
  • purified igg
  • rabbit igg
  • serum igg
  • specific igg
  • total igg

  • Terms modified by IgG

  • igg acl
  • igg anti
  • igg antibody
  • igg antibody response
  • igg antibody titer
  • igg autoantibody
  • igg bands
  • igg binding
  • igg class
  • igg concentration
  • igg deposition
  • igg fraction
  • igg isotype
  • igg level
  • igg molecule
  • igg positive
  • igg production
  • igg response
  • igg sample
  • igg secretion
  • igg subclass
  • igg subclass response
  • igg synthesis
  • igg titer
  • igg titre

  • Selected Abstracts


    Adventures in multivalency, the Harry S. Fischer memorial lecture CMR 2005; Evian, France

    CONTRAST MEDIA & MOLECULAR IMAGING, Issue 1 2006
    Michael F. Tweedle
    Abstract This review discusses multivalency in the context of drug discovery, specifically the discovery of new diagnostic imaging and related agents. The aim is to draw attention to the powerful role that multivalency plays throughout research involving molecular biology, in general, and much of biochemically targeted contrast agent research, in particular. Two examples from the author's laboratory are described. We created small (,5,kDa) peptide ,dimers' composed of two different, chemically linked peptides. The monomer peptides both bound to the same target protein with Kd,,,100,s,nM, while the heterodimers had sub-nM Kd values. Biological activity was evident in the heterodimers where none or very little existed in homodimers, monomers or monomer mixtures. Two different tyrosine kinases (KDR and C-Met) and four peptide families produced consistent results: multivalent heterodimers were uniquely different. The second example begins with making two micron ultrasound bubbles coated with the peptide, TKPPR (a Tuftsin antagonist) as a negative control for bubbles targeted with angiogenesis target-binding peptides. Unexpected binding of a ,negative' control, (TKPPR)-targeted bubble to endothelial cells expressing angiogenesis targets, led to the surprising result that TKPPR, only when multimerized, binds avidly, specifically and actively to neuropilin-1, a VEGF co-receptor. VEGF is the primary stimulator of angiogenesis. Tuftsin is a small peptide (TKPR) derived from IgG that binds to macrophages during inflammation, and has been studied for over 30 years. The receptor has never been cloned. The results led to new conclusions about Tuftsin, neuropilin-1 and the purpose, up to now unknown, of exon 8 in VEGF. Multivalency can be used rationally to solve practical problems in drug discovery. When targeting larger structures, multivalency is frequently unavoidable, and can lead to unpredictable and useful biochemical information, as well as to new drug candidates. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Human peripheral blood B-cell compartments: A crossroad in B-cell traffic,

    CYTOMETRY, Issue S1 2010
    M. Perez-Andres
    Abstract A relatively high number of different subsets of B-cells are generated through the differentiation of early B-cell precursors into mature B-lymphocytes in the bone marrow (BM) and antigen-triggered maturation of germinal center B-cells into memory B-lymphocytes and plasmablasts in lymphoid tissues. These B-cell subpopulations, which are produced in the BM and lymphoid tissues, recirculate through peripheral blood (PB), into different tissues including mucosa and the BM, where long-living plasma cells produce antibodies. These circulating PB B-cells can be classified according to their maturation stage into i) immature/transitional, ii) naïve, and iii) memory B-lymphocytes, and iv) plasmablasts/plasma cells. Additionally, unique subsets of memory B-lymphocytes and plasmablasts/plasma cells can be identified based on their differential expression of unique Ig-heavy chain isotypes (e.g.: IgM, IgD, IgG, IgA). In the present paper, we review recent data reported in the literature about the distribution, immunophenotypic and functional characteristics of these cell subpopulations, as well as their distribution in PB according to age and seasonal changes. Additional information is also provided in this regard based on the study of a population-based cohort of 600 healthy adults aged from 20 to 80 years, recruited in the Salamanca area in western Spain. Detailed knowledge of the distribution and traffic of B-cell subsets through PB mirrors the immune status of an individual subject and it may also contribute to a better understanding of B-cell disorders related to B-cell biology and homeostasis, such as monoclonal B-cell lymphocytosis (MBL). © 2010 International Clinical Cytometry Society [source]


    Neonatal cerebral ischaemia with elevated maternal and infant anticardiolipin antibodies

    DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 6 2000
    Gabriel Chow MBBChir BSc DCH MRCPI MRCPCH
    A baby girl born by elective lower segment caesarean section was found to have left-sided focal seizures at 48 hours after birth. Her mother had previously had a neonatal death at 26 weeks' gestation and another child born at 32 weeks' gestation had a congenital right hemiplegia with a left middle cerebral artery infarct on CT scan. The mother had raised anticardiolipin IgG antibodies at the time of delivery of her second child, with no thrombotic symptoms. Therefore, during this pregnancy, she had been treated with low molecular weight heparin and aspirin. The baby's mother had raised IgG and IgM anticardiolipin antibodies and the baby had IgG anticardiolipin antibodies at the upper range of normal 4 days after delivery. The seizures were controlled with phenobarbitone and phenytoin. CT and MRI scans showed evidence of cerebral ischaemia. A repeat MRI scan at 4 months of age was normal, anticonvulsants were discontinued, and her latest neurological examination at 5 months was normal. [source]


    Ex vivo TCR-induced leukocyte gene expression of inflammatory mediators is increased in type 1 diabetic patients but not in overweight children

    DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 1 2010
    Jaime S. Rosa
    Abstract Background Abnormal systemic concentrations of proinflammatory cytokines/chemokines have been implicated in the development of long-term cardiovascular complications in type 1 diabetes (T1DM) and obesity. Whether leukocyte white blood cell (WBC) gene expression of these proinflammatory mediators contributes to their increased systemic levels, however, remains unclear, especially in the pediatric patient populations. This study examines mRNA changes of 9 cytokines and chemokines in WBCs following ex vivo immunostimulation from 9 T1DM (13.4 ± 0.5 year, 4F/5 M), 23 overweight (OW, 12.3 ± 0.5 year, 10F/13M, BMI% 97.1 ± 0.5 and > 90.0), and 21 healthy (CL, 13.8 ± 0.7 year, 9F/12 M, BMI% 59.6 ± 4.6 and < 85.0) children. Methods All subjects had been maintained in euglycemic conditions for at least 90 min before blood draws. Whole blood was then sampled and incubated with anti-T-cell receptor (TCR) antibody or heat-aggregated IgG (HAG) to stimulate T-cell and Fc receptors (FcR), respectively. After lysis of leukocytes, mRNA levels of six tumor necrosis factor superfamily cytokines (TNFSF2, 5, 6, 7, 9, 14) and three chemokines (CCL8, 20, and CXCL10) were measured using RT-PCR. Results Following TCR stimulation, T1DM displayed significantly greater mRNA responses than CL for TNFSF5, 7, 9, and CCL8, and CXCL10; TNFSF9, CCL8, and CXCL10 were also significantly higher in T1DM than OW; no difference was observed between OW and CL. FcR stimulation induced similar responses across groups. Conclusions Leukocytes of T1DM children displayed exaggerated gene expression in response to ex vivo TCR induction of five key proinflammatory cytokines/chemokines. This elevated leukocyte gene expression may be one of the pathophysiological contributors to the development of vascular complications in T1DM. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    Circulating insulin antibodies: influence of continuous subcutaneous or intraperitoneal insulin infusion, and impact on glucose control

    DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2009
    R. P. Radermecker
    Abstract The purification of animal insulin preparations and the use of human recombinant insulin have markedly reduced the incidence, but not completely suppressed, the development of anti-insulin antibodies (IAs). Advances in technologies concerning the mode of delivery of insulin, i.e. continuous subcutaneous insulin infusion (CSII), continuous peritoneal insulin infusion (CPII) and more recently inhaled insulin administration, appear to significantly increase circulating levels of immunoglobulin G (IgG) anti-IAs in diabetic patients. However, the increase is usually moderate and mostly transient as compared to previous observations with poorly purified animal insulin preparations. The clinical impact of these circulating anti-IAs remains unclear. Nevertheless, several studies have suggested that antibodies could retard insulin action, leading to a worsening of postprandial hyperglycaemia and/or serve as a carrier, thus leading to unexpected hypoglycaemia. CPII may be associated with more marked and sustained increase in IAs levels, possibly related to the use of an unstable insulin and the formation of immunogenic aggregates of insulin. The possible clinical consequences of these high levels of IAs remain to be evaluated because a low-glucose morning syndrome or severe insulin resistance with ketone bodies production have been reported in some cases. In conclusion, even if CSII and CPII may promote the development of circulating IAs, this increase does not lead to immunological insulin resistance, compared to that previously described with animal non-purified insulin preparations, and seems to have only marginal influence on blood glucose control or complications in most diabetic patients. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    Platform for Highly Sensitive Alkaline Phosphatase-Based Immunosensors Using 1-Naphthyl Phosphate and an Avidin-Modified Indium Tin Oxide Electrode

    ELECTROANALYSIS, Issue 19 2009
    Abdul Aziz
    Abstract We report a versatile platform for highly sensitive alkaline phosphatase (ALP)-based electrochemical biosensors that uses an avidin-modified indium tin oxide (ITO) electrode as a sensing electrode and 1-naphthyl phosphate (NPP) as an ALP substrate. Almost no electrocatalytic activity of NPP and good electrocatalytic activity of 1-naphthol (ALP product) on the ITO electrodes allow a high signal-to-background ratio. The effective surface covering of avidin on the ITO electrodes allows very low levels of nonspecific binding of proteins to the sensing electrodes. The platform technology is used to detect mouse IgG with a detection limit of 1.0,pg/mL. [source]


    Microfluidic devices for electrokinetic sample fractionation

    ELECTROPHORESIS, Issue 15 2010
    Zhen Wang
    Abstract We present three generations of microchip-based "in-space" sample fractionators and collectors for use in proteomics. The basic chip design consisted of a single channel for CE separation of analytes that then intersects a fractionation zone feed into multiple high aspect ratio microchannels for fractionation of separated components. Achievements of each generation are discussed in relation to important design criteria. CE-separated samples were electrokinetically driven to multiple collection channels in sequence without cross-contamination under the protection of sheath streams. A 36-channel fractionator demonstrated the efficacy of a high-throughput fractionator with no observed cross-contamination. A mixture of IgG and BSA was used to test the efficiency of the fractionator and collector. CE of the fractionated samples was performed on the same device to verify their purity. Our demonstration proved to be efficient and reproducible in obtaining non-contaminated samples over 15 sample injections. Experimental results were found to be in close agreement with PSpice simulation in terms of flow behavior, contamination control and device performance. The design presented here has a great potential to be integrated in proteomic platforms. [source]


    A new evaluation technique for the detection of impurities in purified proteins via CE with native UV-LIF

    ELECTROPHORESIS, Issue 2 2010
    Audrey Rodat
    Abstract An analytical methodology for quality control analyses of IgG and their impurities is presented using a new UV-LIF (266,nm) detector inside the cassette of a CE instrument and its performance was evaluated. The observed sensitivity was very close to that obtained by silver staining of slab gels (LOD of 25,ng/mL), while the sensitivity of the analysis is 80 times better than with CE/UV absorption (214,nm). Examples of the analysis of pharmaceutical and other commercial IgGs are provided and the kinetics of the reduction of IgG by ,-mercaptoethanol is reported, demonstrating the ease of performing the analysis. [source]


    CE-based noncompetitive immunoassay for immunoglobulin G in bovine colostrum products

    ELECTROPHORESIS, Issue 21 2007
    Jin Zhao
    Abstract A CE-based noncompetitive immunoassay for IgG in bovine colostrum products was established. FITC-labeled protein G (FITC-PrG) was tagged through noncovalent bindings to the Fc region of the mouse monoclonal antibovine IgG (Ab). The FITC-PrG, Ab, and IgG formed a sandwiched immunocomplex FITC-PrG-Ab-IgG under optimal incubation conditions. The immunocomplex was separated and analyzed by CZE with LIF detection in less than 2,min in an uncoated fused-silica capillary. Addition of PEG 20,000 (PEG 20M) in the running buffer significantly suppressed analyte adsorption and thus improved the reproducibility and the resolution. The precision of the method was 5.1% (n,=,7). A linear relationship was established for the IgG concentration in the range of 1,5,mg/L with a linear correlation coefficient (r,=,0.9917). The LOD was 0.1,mg/L (S/N,=,3). The method was successfully applied for the determination of IgG in bovine colostrum products and satisfactory results were achieved. [source]


    Biomarker discovery in breast cancer serum using 2-D differential gel electrophoresis/ MALDI-TOF/TOF and data validation by routine clinical assays

    ELECTROPHORESIS, Issue 8 2006
    Hong-Lei Huang
    Abstract In the present study, we used 2-D differential gel electrophoresis (2-D DIGE) and MS to screen biomarker candidates in serum samples obtained from 39,patients with breast cancer and 35,controls. First, we pooled the serum samples matched with age and menopausal status. Then, we depleted the two most abundant proteins albumin and IgG by immunoaffinity chromatography under partly denaturing conditions in order to enrich low-abundance proteins and proteins with low molecular weight. Concentrated and desalted samples were labeled with three different CyDyes including one internal standard, pooled from all the samples, and separated with 2-D DIGE in triplicate experiments. Biological variations of the protein expression level were analyzed with DeCyder software and evaluated for reproducibility and statistical significance. The profile of differentially expressed protein spots between patients and controls revealed proapolipoprotein A-I, transferrin, and hemoglobin as up-regulated and three spots, apolipoprotein,A-I, apolipoprotein,C-III, and haptoglobin,,2 as down-regulated in patients. Finally, routine clinical immunochemical reactions were used to validate selected candidate biomarkers by quantitative determination of specific proteins in all individual serum samples. The serum level of transferrin correlated well with the 2-D-DIGE results. However, the serum levels of apolipoprotein A-I and haptoglobin could not be detected with the clinical routine diagnostic tests. This demonstrated an advantage 2-D DIGE still has over other techniques. 2-D DIGE can distinguish between isoforms of proteins, where the overall immunochemical quantification does fail due to a lack of isoform-special antibodies. [source]


    Fast immobilization of probe beads by dielectrophoresis-controlled adhesion in a versatile microfluidic platform for affinity assay

    ELECTROPHORESIS, Issue 19 2005
    Janko Auerswald Dr.
    Abstract The use of probe beads for lab-on-chip affinity assays is very interesting from a practical point of view. It is easier to handle and trap beads than molecules in microfluidic systems. We present a method for the immobilization of probe beads at defined areas on a chip using dielectrophoresis (DEP)-controlled adhesion. The method is fast, i.e., it takes between 10 and 120,s , depending on the protocol , to functionalize a chip surface at defined areas. The method is versatile, i.e., it works for beads with different types of probe molecule coatings. The immobilization is irreversible, i.e., the retained beads are able to withstand high flow velocities in a flow-through device even after the DEP voltage is turned off, thus allowing the use of conventional high-conductivity analyte buffers in the following assay procedure. We demonstrate the on-chip immobilization of fluorescent beads coated with biotin, protein,A, and goat,antimouse immunoglobulin G (IgG). The number of immobilized beads at an electrode array can be determined from their fluorescence signal. Further, we use this method to demonstrate the detection of streptavidin and mouse IgG. Finally, we demonstrate the feasibility of the parallel detection of different analyte molecules on the same chip. [source]


    Carbamazepine-induced drug-induced hypersensitivity syndrome in a 14-year-old Japanese boy

    EPILEPSIA, Issue 12 2008
    Yuka Suzuki
    Summary Drug-induced hypersensitivity syndrome (DIHS) is a life-threatening idiosyncratic drug reaction, and an early accurate diagnosis is essential for its treatment. We describe a 14-year-old boy with localization-related epilepsy, who developed severe adverse cutaneous and systemic reactions after 3 weeks of carbamazepine administration. During the course of the clinical symptoms, reactivation of human herpesvirus 6 (HHV-6) was proven by detection of the HHV-6 genome in serum and elevation of HHV-6 immunoglobulin G (IgG). He fulfilled the newly established criteria for DIHS. Among eight identified medications that can precipitate DIHS, four are antiepileptic drugs. Establishing a treatment strategy for DIHS is warranted to improve its outcome. Therefore, it is important to raise awareness of DIHS among epileptologists. [source]


    Faecal shedding and serological cross-sectional study of Lawsonia intracellularis in horses in the state of Minas Gerais, Brazil

    EQUINE VETERINARY JOURNAL, Issue 6 2009
    C. V. Guimarães-Ladeira
    Summary Reason for performing the study: Proliferative enteropathy, caused by the intracellular bacterium Lawsonia intracellularis, has been described in horses in Australia, the USA, Canada and European countries but has not been reported in Latin America. The prevalence of the disease in horses worldwide is unknown. Objective: To evaluate the presence of subclinical L. intracellularis infection in horses in the state of Minas Gerais, Brazil. Methods: A longitudinal study using serology and PCR for detecting antibodies (IgG) and shedding of L. intracellularis in faecal samples, respectively, was conducted using a total of 223 horses from 14 different horse farms in Minas Gerais, and from the Veterinary School of UFMG equine herds in Minas Gerais. The immunoperoxidase technique in glass slides was used as the serological test. Results: Twenty-one horse sera had immunoglobulin G titres of 1:60 and were considered positive. The PCR technique in faeces for L. intracellularis DNA identified 7 horses as faecal shedders. Horses shedding the organism appeared healthy, indicating that subclinical infection of L. intracellularis occurred in the horses. Conclusion: Seropositivity and detection of faecal shedding of L. intracellularis indicates the presence of the agent in the equine population in Minas Gerais. Potential relevance: Results of this study should alert clinicians in countries where proliferative enteropthy in horses has not been reported to consider this disease as a possible cause of enteric disease. [source]


    Interference in thyroid-stimulating hormone determination

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 8 2010
    Mauro Imperiali
    Eur J Clin Invest 2010; 40 (8): 756,758 Abstract Background, Thyroid-stimulating hormone (TSH) measurement plays a major role in the diagnosis of thyroid disorders. Despite the good quality of immunochemical tests measuring TSH levels, the presence of interfering substances can sometimes alter the TSH results. Design, We reported the case of a 79-year-old man affected by primary autoimmune hypothyroidism hospitalized for pneumonia. A TSH value > 100 mIU L -1 (reference: 0.44 mIU L -1) was found at admission. No signs and symptoms of hypothyroidism were found upon clinical examination and serum concentration of the free thyroxine (FT4) was normal. Results, Serum treatment in heterophile antibody blocking tubes did not change the TSH result in our assay, while normal levels were found in a different immunoassay method. An abnormal pattern was found in protein electrophoresis at admission, with IgG / j and IgM / k monoclonal bands proved in immunofixation. Interestingly, the disappearance of monoclonal bands was paralleled with a normalization of the TSH value. Conclusions, We suggest in this study that the TSH determination might be influenced by the presence of transient paraproteins. [source]


    Clinical importance of antibodies against platelet activating factor in antiphospholipid syndrome manifestations

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 7 2000
    Tektonidou
    Background We assessed whether antibodies against platelet activating factor (PAF) are related to the presence of antiphospholipid syndrome (APS) clinical manifestations, in particular thrombosis, in patients with connective tissue diseases. Materials and methods Anti-PAF, anticardiolipin (aCL), anti,2 glycoprotein I (anti,2GPI) and antiphosphatidylcholine (anti-PC) antibodies were determined in 52 patients with APS, 29 patients with systemic lupus erythematosus (SLE) aCL but without APS, 30 patients with SLE without aCL, and 30 patients with scleroderma. A new enzyme-linked immunosorbent assay (ELISA) was developed for determining anti-PAF antibodies in a bovine serum-free fashion. Results The ELISA showed high specificity. Homologous inhibition experiments showed 60,70% inhibition. Anti-PAF antibodies were found in 18/52 APS patients, 10/29 SLE/aCL+ patients, 9/30 SLE/aCL, patients and 3/30 scleroderma patients. Anti-PAF antibodies were significantly associated with anti-PC antibodies (odds ratio [OR] 12.7, P < 0.01), and there was a modest association with immunoglobulin G (IgG) aCL (OR 3.1, P > 0.10), but not with IgM aCL or anti,2GPI. Three SLE/aCL+ patients and five SLE/aCL, patients had clinical manifestations characteristic of APS. All these patients had anti-PAF antibodies, while none had high titres of aCL or anti,2GPI antibodies and only one had anti-PC antibodies. Among the combined APS and SLE groups, the presence of anti-PAF antibodies was significantly associated with clinical manifestations which are characteristic of APS (OR 2.6, P = 0.02). The effect was independent of IgG aCL and anti,2GPI antibodies. Conclusions Anti-PAF antibodies are common in APS and SLE and comprise an independent factor for the development of thrombosis. Several patients experiencing thromboses have anti-PAF antibodies without other antiphospholipid specificities. [source]


    Efficacy of single-agent bortezomib vs. single-agent thalidomide in patients with relapsed or refractory multiple myeloma: a systematic comparison

    EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 2 2007
    H. Miles Prince
    Abstract Objective:, To conduct a systematic review of the efficacy of single-agent bortezomib vs. single-agent thalidomide in patients with relapsed/refractory multiple. Methods:, Publications in English from 1966 to June 2005 (MEDLINE, EMBASE, Cochrane library), publication reference lists, Janssen-Cilag data-on-file and abstracts from recent multiple myeloma conferences were reviewed. Prospective studies containing at least a single arm of either treatment group with n,30 were included. Studies adding dexamethasone for non-responders were excluded. Statistical pooling was performed for response rate and overallsurvival. Results:, One bortezomib study (n = 333, NEJM 2005, 352; 2487,98) and 15 thalidomide (n = 1007) studies met these criteria and were included. Patient baseline characteristics including age, gender, IgG : IgA, disease duration and beta-2 microglobulin were well matched except that 48% of bortezomib patients had received prior thalidomide. Response rate, defined as serum M-protein reduction ,50%, was 53% for patients receiving bortezomib vs. 32% for thalidomide (P < 0.001, n = 10 studies). Response rate determined by European Group for Blood and Marrow Transplantation (EBMT) criteria was 41% for patients receiving bortezomib vs. 22% for thalidomide (P < 0.001, n = 4 studies). Conclusion:, Bortezomib was associated with a significantly higher response rate and complete remission rate using both M-protein and EBMT criteria. [source]


    FCRL6 distinguishes mature cytotoxic lymphocytes and is upregulated in patients with B-cell chronic lymphocytic leukemia

    EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2008
    Daniel M. Schreeder
    Abstract Fc receptor-like 6 (FCRL6), the most recently characterized member of the FCRL family, is a cell surface glycoprotein with tyrosine-based regulatory potential. An extensive survey of human hematopoietic tissues disclosed that FCRL6 expression by NK- and T-cell subpopulations increases as a function of differentiation and is remarkably restricted to mature lymphocytes with cytotoxic capability. In particular, FCRL6 distinguishes perforin-expressing CD56dim NK cells, V,1+ and V,2+ ,, T cells, effector and effector memory CD8+ T cells, and rare cytotoxic CD4+ T cells in adult tissues. Analysis of this receptor in B-cell chronic lymphocytic leukemia (CLL) was also performed. FCRL6 was found to mark significantly expanded populations of cytotoxic CD8+ T, CD4+ T, and NK cells in patients with CLL. Despite sequence homology with the known Fc receptors for IgG and IgE, FCRL6 did not bind Ig. Although FCRL6 can be tyrosine-phosphorylated, its antibody-mediated ligation was unable to influence cellular activation. Collectively, these results demonstrate that FCRL6 is a distinct indicator of cytotoxic effector lymphocytes that is upregulated in diseases characterized by chronic immune stimulation. [source]


    The adhesion receptor CD155 determines the magnitude of humoral immune responses against orally ingested antigens

    EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2007
    Michael
    Abstract CD155, originally known as the cellular receptor for poliovirus, is the founding member of a subfamily of immunoglobulin-like adhesion receptors. Apart from its function in establishing adherens junctions between contacting epithelial cells, the engagement of CD155 with two recently identified ligands, CD226 and CD96, mediates immunologically relevant processes such as NK cell-driven killing of tumor cells in humans. Here we report on the generation and immunological analysis of mice constitutively deficient of CD155. Moreover, the expression profile of CD155 on hematopoietic cells has been determined using newly established antibodies. CD155-deficient mice develop normally without displaying an overt phenotype. However, the animals are distinguished by distinct deficits in the development of a regular humoral immune response. Whereas systemic challenges revealed no differences, orally administered antigen evoked less efficient IgG and IgA antibody responses despite of normal IgM titers when compared to wild-type mice. Therefore, CD155 may assist in an efficient humoral immune response generated within the intestinal immune system. [source]


    Fc,RIIB deficiency with Fas mutation is sufficient for the development of systemic autoimmune disease

    EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2003
    Kaori Yajima
    Abstract MRL.Faslpr/lpr mice, a model for systemic lupus erythematosus (SLE) and arthritis in humans, have a Fas mutation that results in spontaneous development of systemic autoimmune diseases and a short life span. Half of them die by 5,6,months of age due to massive progression of systemic autoimmune diseases, such as lupus nephritis. However, C57BL/6 (B6).Faslpr/lpr strain does not develop such disorders within the normal life span, indicating that suppressor gene(s) in B6 mice may control the onset and exacerbation of disease. Here, we show that the gene for a unique inhibitory Fc receptor for IgG (Fc,RIIB) is a critical SLE suppressor. Fc,RIIB-deficient B6.Faslpr/lpr (B6.IIB,/,Faslpr/lpr) mice developed systemic autoimmune diseases, including anti-DNA and anti-type,II collagen autoantibodies and cryoglobulin production, immune complex glomerulonephritis and arthritis. They were short-lived, due to enhanced autoantibody production by B cells culminating in fatal lupus nephritis. Thus, Fc,RIIB deletion with Fas mutation is sufficient for the development of systemic autoimmunity in B6 mice. The inhibitory signaling cascade via Fc,RIIB may be critical for suppressing SLE in humans. [source]


    The association between Anti-EBNA-1 IgG and multiple sclerosis clinical disease activity , response

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 10 2010
    G. Ingram
    No abstract is available for this article. [source]


    MS and clinically isolated syndromes: Shared specificity but diverging clonal patterns of virus-specific IgG antibodies produced in vivo and by CSF B cells in vitro

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 10 2009
    G. Skorstad
    Background:, Intrathecal synthesis of oligoclonal IgG antibodies against measles virus (MeV), varicella zoster virus (VZV) and herpes simplex virus type-1 (HSV-1) is a characteristic feature multiple sclerosis (MS). Methods:, We have used isoelectric focusing-immunoblot to define the clonal patterns of IgG and of IgG antibodies to MeV, VZV and HSV-1 in supernatants of in vitro cultures of peripheral blood lymphocytes (PBL) and cerebrospinal fluid (CSF) cells and in sera and CSF from three patients with MS and three patients with clinically isolated syndromes (CIS) suspective of demyelinating disease. Results:,In vitro synthesis of IgG by PBL was not detected in any patient. In contrast, in vitro synthesis by CSF cells of oligoclonal IgG and oligoclonal IgG antibodies to one or two of the three viruses tested was observed in all six patients. The clonal patterns of the in vitro synthesized IgG and virus specific IgG differed to varying extent from those synthesized intrathecally in vivo. However, in each patient, the in vitro and in vivo intrathecally produced antibodies displayed specificity for the same viruses. The addition of B cell activating factor (BAFF) had no effect on the amounts or clonal patterns of either total IgG or virus-specific IgG produced by CSF cells in vitro. Conclusion:, Virus specific B cells capable of spontaneous IgG synthesis are clonally expanded in the CSF of patients with MS. The B-cell repertoire in CSF samples is only partially representative of the intrathecal B-cell repertoire. [source]


    Brain barrier dysfunction in Cuban Epidemic Optic Neuropathy

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2008
    A. González-Quevedo Monteagudo
    Background and purpose:, There are practically no references to cerebrospinal fluid(CSF) studies in tropical or nutritional neuropathies. In the present paper we present the results of CSF studies in patients with Cuban Epidemic Optic Neuropathy (CEON) during epidemic and endemic periods, with an appraisal as to the contribution of brain barriers, function in the pathophysiology of this disease. Methods:, Two hundred and five patients with CEON were studied during the epidemic period (1992,1993) and 12 patients outside the outbreak (1995,1997). CSF protein determination and electrophoresis were carried out, as well as serum and CSF albumin and immunoglobulin G (IgG) quantitation for calculating IgG and Qalb indexes, in order to evaluate intrathecal IgG synthesis and the permeability of the blood,CSF barrier (B-CSF B). Results:, One fourth of the patients had increased permeability of the B-CSF B, but damage was more frequent between 16 and 60 days from onset of disease, disappearing after 120 days. B-CSF B dysfunction was more prevalent in patients with severe neurological impairment, although it was not related to the severity of ophthalmological damage. The group of patients studied outside of the outbreak (endemic period) showed similar results. Discussion:, The possible association of increased permeability of the B-CSF B with oxidative stress, which lies on the basis of this epidemic outbreak, is discussed. [source]


    Epstein,Barr virus reactivation and multiple sclerosis

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2008
    Ø. Torkildsen
    Infection with Epstein,Barr virus (EBV) is considered one of the possible key environmental factors in the aetiology of multiple sclerosis (MS). Whether EBV plays an underlying role as an activator of MS remains, however, controversial. Sixty-one patients with definite relapsing,remitting multiple sclerosis (RRMS) according to the Poser criteria were followed for 1 year. Blood samples were drawn at baseline, months 3, 6 and 12, and in case of any clinical exacerbation. Twenty-three baseline,paired exacerbation samples in the same set were quantitatively analysed to examine whether exacerbations in MS were associated with a change in anti-diffuse component of the EBV-early antigen (EA-D) IgG ratio. All the 61 patients (100%) were anti-viral capsid antigen (VCA) IgG positive, one (2%) was anti-VCA IgM positive and 60 (98%) were anti-EBV nuclear antigen IgG positive. Mean anti-EA-D IgG at baseline was 0.57 (range 0.12,2.70) and at the time of exacerbations 0.61 (range 0.11,2.70). Wilcoxon signed rank test revealed no differences between the 23 baseline and paired exacerbation samples (P = 0.58). Our findings suggest that reactivation of latent EBV infection does not play a significant role for exacerbations in RRMS. [source]


    Antigen-specific oligoclonal bands in cerebrospinal fluid and serum from patients with anti-amphiphysin- and anti-CV2/CRMP5 associated paraneoplastic neurological syndromes

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2007
    O. Stich
    Using isoelectric focusing and affinity blotting employing paraneoplastic recombinant antigens, we investigated cerebrospinal fluid (CSF) and sera from three patients with positive anti-CV2/CRMP5- and one patient with positive anti-amphiphysin serology. CSF and sera were previously adjusted to total IgG concentrations of 20 mg/l. All patients suffered from paraneoplastic neurological syndromes (PNS) with predominant involvement of the central nervous system (CNS). Using affinity blot preloaded with paraneoplastic antigen, we detected in three of four patients more or stronger specific oligoclonal bands (OCB) in the CSF than in the corresponding serum, providing qualitative evidence of antigen specific intrathecal antibody synthesis. These results are in line with previous studies demonstrating specific OCB predominantly in CSF from patients with anti-Hu-, anti-Yo- and anti-Ri-associated PNS, supporting the hypothesis of autoimmunity in the pathogenesis of PNS. One patient harboured extensive anti-amphiphysin specific OCB, although OCB of total IgG could not be detected, indicating a higher sensitivity for detection of intrathecal antibody synthesis of the affinity blot preloaded with the paraneoplastic antigen, compared with investigation of total IgG OCB. These results could have implications concerning pathophysiological autoimmune aspects in other inflammatory diseases of CNS associated with total IgG OCB, provided that the target antigen is known. [source]


    CSF analysis in patients with sporadic CJD and other transmissible spongiform encephalopathies

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2007
    A. Green
    Patients with suspected Creutzfeldt,Jakob disease (CJD) often have routine cerebrospinal fluid (CSF) analysis performed to exclude treatable inflammatory conditions; however, little information is available about the range of results obtained for CSF tests in patients with sporadic CJD and other transmissible spongiform encephalopathies (TSE). Data from 450 patients with sporadic CJD and 47 patients with other TSEs were collected as part of an EC-supported multinational study. Raised white cell counts of >5 cells/,l were found in three of 298 patients with sporadic CJD, with two cell counts of 7 cells/,l and one of 20 cells/,l. Total protein concentrations of >0.9 g/l were found in five of 438 patients with sporadic CJD, although none had a concentration of >1 g/l. CSF oligoclonal IgG was detected in eight of 182 sporadic CJD patients. Of the patients with other TSEs, six had elevated cell counts ranging from 6 to 14 cells/,l but none had total protein concentrations of >0.9 g/l and one patient had detectable oligoclonal IgG. None of the patients with sporadic CJD or other TSEs had abnormalities in all three tests. [source]


    Deposition of chromatin-IgG complexes in skin of nephritic MRL-lpr/lpr mice is associated with increased local matrix metalloprotease activities

    EXPERIMENTAL DERMATOLOGY, Issue 8 2010
    Annica Hedberg
    Please cite this paper as: Deposition of chromatin-IgG complexes in skin of nephritic MRL-lpr/lpr mice is associated with increased local matrix metalloprotease activities. Experimental Dermatology 2010; 19: e265,e274. Abstract:, Chromatin-IgG complexes appear as electron dense structures (EDS) in glomerular basement membranes in lupus nephritis. Here, we present results of comparative analyses of the composition of EDS in murine lupus dermatitis and nephritis. One focus was to perform an analytical approach to understand why such complex structures bind skin basement membrane components. Transcription of skin membrane-encoding genes was analysed to see if expression of such genes was increased, eventually indicating that binding capacity of immune complexes increased when dermatitis developed. Variations in matrix metalloprotease 2 (MMP2), MMP9 and Dnase1 mRNA levels and enzymatic activities were correlated with circulatory chromatin-IgG complexes and deposition in skin. We also examined if glomerular deposits of EDS predicted similar deposits in skin of (NZB × NZW)F1 or MRL-lpr/lpr mice, as we observed chromatin-IgG complexes in capillary lumina in skin and glomeruli in both strains. EDS consisting of chromatin fragments and IgG were found sub-epidermally in skin with LE-like lesions of end-stage nephritic MRL-lpr/lpr mice. Dermal MMP-encoding genes were up-regulated during disease progression, and gelatinolytic activity was increased in affected skin. Dnase1 mRNA level and total nuclease activity remained stable in skin during the disease, in contrast to progressive loss of renal Dnase1 mRNA and total renal nuclease activity during development of nephritis. Loss of renal Dnase1 may explain release of chromatin fragments, while increased MMP activity may disrupt membranes making them accessible for chromatin fragment-IgG complexes. Circulatory chromatin-IgG complexes, and up-regulated intradermal MMP activity may be crucial for deposition of immune complexes in skin of lupus-prone mice. [source]


    Pemphigus mouse model as a tool to evaluate various immunosuppressive therapies

    EXPERIMENTAL DERMATOLOGY, Issue 3 2009
    Yujiro Takae
    Abstract:, Pemphigus vulgaris (PV) is an autoimmune bullous disease caused by immunoglobulin G (IgG) autoantibodies against desmoglein 3 (Dsg3). We have generated an active disease mouse model for PV by adoptive transfer of Dsg3,/, lymphocytes. In this study, we investigated the benefits and limitations of this model as a tool to evaluate various immunosuppressive therapeutic strategies. We used the following three measurements to evaluate the effects of the drugs during the time course: Dsg3 enzyme-linked immunosorbent assay scores that represent the level of production of anti-Dsg3 IgG, body weight loss that reflects the severity of oral erosions and PV score that reflects the extent of skin lesions. We examined various immunosuppressive agents currently used to treat patients with PV model mice in preventive protocol. Cyclophosphamide almost completely suppressed the production of anti-Dsg3 IgG, development of body weight loss and the appearance of the PV phenotype in contrast with the control group without the drug. Azathioprine, cyclosporin A and tacrolimus hydrate also showed suppressive effects to various degrees. However, methylprednisolone and dexamethasone failed to show significant effects in contrast to the findings reported in humans. Knowing the advantages and limitations of this model will provide an important foundation for the future evaluation and development of novel therapeutic strategies. [source]


    Constitutive Secretion of Immunoglobulin a and Other Proteins into Lumina of Unstimulated Submandibular Glands in Anaesthetised Rats

    EXPERIMENTAL PHYSIOLOGY, Issue 1 2003
    G. B. Proctor
    Salivary fluid secretion is dependent upon reflex stimuli mediated by autonomic nerves. In order to determine if immunoglobulin A (IgA) and salivary proteins are secreted in the absence of nerve stimulation, small volumes (< 2 µl) of saliva were consecutively collected from the submandibular duct of anaesthetised rats following rest pauses in order to sample the protein contents of the ductal system. Within the first 5 µl of such saliva collected by parasympathetic nerve stimulation, IgA and other salivary proteins reached peak concentrations that were over 20-fold greater than levels in parasympathetically stimulated saliva subsequently collected during a 5 min period of stimulation. Confocal microscopy of TRITC-labelled IgA added to live, acutely isolated submandibular acini indicated that it did not enter the lumina by paracellular leakage. IgG is thought to enter saliva by paracellular leakage but did not accumulate in luminal saliva in the present study. Electrophoresis suggested that the major proteins secreted in the absence of stimulation were the same as those present in subsequently stimulated saliva. It can be concluded that IgA and other major submandibular proteins are secreted into glandular lumina in the absence of nerve stimulation. The functional significance of such unstimulated protein secretion is at present unclear. [source]


    Detailed characterization of polydnavirus immunoevasive proteins in an endoparasitoid wasp

    FEBS JOURNAL, Issue 10 2002
    Kohjiro Tanaka
    Polydnaviruses are a unique group of insect viruses in terms of their obligate and symbiotic associations with some parasitic wasps. The Cotesia kariyai polydnavirus (CkPDV) replicates only in ovarian calyx cells of C. kariyai female wasps and is injected into the wasp's host, the armyworm Pseudaletia separata, along with the eggs. A previous study indicated the possibility that one of the CkPDV surface proteins mediates immunoevasion by the wasp from the encapsulation reaction of the host insect's hemocytes. This protein was named immunoevasive protein (IEP). The present studies substantially confirmed the previous observation by showing that an anti-IEP IgG neutralizes immunoevasive activity on the wasp eggs. Further, we isolated the IEP homologue (IEP-2) cDNA and IEP (IEP-1) cDNA, sequenced them and found that both are cysteine-rich proteins, each containing epidermal growth factor (EGF)-like repeats. IEP genes were not found to reside in the CkPDV genome, but in the wasp chromosomal DNA. IEPs are synthesized in the female reproductive tract and their expression was detected from 4 days after pupation, 1 day later than expression of the virus capsid proteins. In situ hybridization and immunocytochemistry indicated that the lateral oviduct cells of the reproductive tracts produce IEP-1/IEP-2 mRNAs and secrete the proteins into the oviduct. These data suggest that the expression pattern and localization of IEPs are different from other components of CkPDV virions. [source]


    Oral vaccination of mice against Helicobacter pylori with recombinant Lactococcus lactis expressing urease subunit B

    FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2009
    Qing Gu
    Abstract To determine whether a protective immune response could be elicited by oral delivery of a recombinant live bacterial vaccine, Helicobacter pylori urease subunit B (UreB) was expressed for extracellular expression in food-grade bacterium Lactococcus lactis. The UreB-producing strains were then administered orally to mice, and the immune response to UreB was examined. Orally vaccinated mice produced a significant UreB-specific serum immunoglobulin G (IgG) response. Specific anti-UreB IgA responses could be detected in the feces of mice immunized with the secreting lactococcal strain. Mice vaccinated orally were significantly protected against gastric Helicobacter infection following a challenge with H. pylori strain SS1. In conclusion, mucosal vaccination with L. lactis expressing UreB produced serum IgG and UreB-specific fecal IgA, and prevented gastric infection with H. pylori. [source]