Search results for "immunoglobulin G"
showing 10 items of 308 documents
Giant liposomes as model membranes for immunological studies: spontaneous insertion of purified K1-antigen (poly-alpha-2,8-NeuAc) of Escherichia coli.
1990
A flow chamber has been constructed to use giant liposomes (diameter 5-50 microns) as model membranes for immunological studies and other experiments involving the interaction with water-soluble compounds. As an example of immunological importance, the insertion of purified K-antigen from Escherichia coli K1 has been studied. Despite its large hydrophilic part (poly-alpha-2,8-NeuAc), which is capped at its potential reducing end with phosphatidic acid acting as a lipid anchor group, this water-soluble material is readily incorporated into liposomal membranes of dimyristoylphosphatidylcholine (DMPC). The incorporation has been proven by immunofluorescence using a FITC-labeled monoclonal anti…
Circulating immune complexes and platelet thromboxane synthesis in patients with insulin-dependent (type I) diabetes mellitus
1984
Platelets from diabetic subjects with circulating immune complexes (CIC) synthesized greater amounts of thromboxane than did platelets from CIC-negative patients or controls. In view of the known action of CIC on platelet function, a relationship between these two factors may be suggested in the initiation and progression of microangiopathy in diabetes.
Analogous IgG subclass response to pertussis toxin in vaccinated children, healthy or affected by whooping cough
2003
The study of antigen specific IgG subclass distribution during disease, or during any other natural or artificial immunisation, can provide useful information on the kind of the immune response and the expected levels of protection. This is particularly true for diseases, such as pertussis in which the mechanisms underlying specific defence are still not completely understood. An investigation was therefore performed to evaluate the IgG subclass response to pertussis toxin (PT) in sera from 89 healthy vaccinated children and 131 vaccinated or unvaccinated children convalescent after a confirmed B. pertussis symptomatic infection. Antibody titres were expressed in arbitrary ELISA units/ml, a…
A Synthetic MUC1 Anticancer Vaccine Containing Mannose Ligands for Targeting Macrophages and Dendritic Cells
2017
A MUC1 anticancer vaccine equipped with covalently linked divalent mannose ligands was found to improve the antigen uptake and presentation by targeting mannose-receptor-positive macrophages and dendritic cells. It induced much stronger specific IgG immune responses in mice than the non-mannosylated reference vaccine. Mannose coupling also led to increased numbers of macrophages, dendritic cells, and CD4+ T cells in the local lymph organs. Comparison of di- and tetravalent mannose ligands revealed an increased binding of the tetravalent version, suggesting that higher valency improves binding to the mannose receptor. The mannose-coupled vaccine and the non-mannosylated reference vaccine ind…
Timing of activation of CD4+ memory cells as a possible marker to establish the efficacy of vaccines against contagious agalactia in sheep
2013
Mycoplasma agalactiae is a major pathogen of sheep and goats in many areas of the world and particularly in Mediterranean countries. It causes contagious agalactia, an infectious disease primarily affecting mammary glands. Many vaccines against the pathogen are currently under development. The aim of the study was to investigate the involvement of T cell-mediated immunity during vaccination and challenge experiments against Mycoplasma agalactiae. A comparison of the antigen-specific expansion of interferon gamma positive T cell memory and naïve subsets was performed between vaccinated and non-vaccinated sheep to identify cellular subsets whose activation was different between protected and …
Uptake and presentation of exogenous antigen and presentation of endogenously produced antigen by skin dendritic cells represent equivalent pathways …
2008
Gene gun-mediated biolistic DNA vaccination with beta-galactosidase (betaGal)-encoding plasmid vectors efficiently modulated antigen-induced immune responses in an animal model of type I allergy, including the inhibition of immunoglobulin E (IgE) production. Here we show that CD4(+) as well as CD8(+) T cells from mice biolistically transfected with a plasmid encoding betaGal under the control of the fascin promoter (pFascin-betaGal) are capable of inhibiting betaGal-specific IgE production after adoptive transfer into naïve recipients. Moreover, suppression of IgE production was dependent on interferon (IFN)-gamma. To analyse the modalities of activation of CD4(+) and CD8(+) T cells regardi…
Human dendritic cells transfected with allergen-DNA stimulate specific immunoglobulin G4 but not specific immunoglobulin E production of autologous B…
2007
Atopic/allergic diseases are characterized by T helper 2 (Th2)-dominated immune responses resulting in immunoglobulin E (IgE) production. DNA-based immunotherapies have been shown to shift the immune response towards Th1 in animal models. In further studies we showed that human dendritic cells (DC) transfected with allergen-DNA are able to stimulate autologous CD4(+) T cells from atopic individuals to produce Th1 instead of Th2 cytokines and to activate interferon-gamma (IFN-gamma)-producing CD8(+) T cells. The aim of this study was to analyse whether DC transfected with allergen-DNA are also able to influence immunoglobulin production of B cells from atopic donors. For this purpose, human …
Immunological pattern in patients with 21-hydroxylase deficiency.
1994
The aim of this work was to perform an immunological study in six patients with 21 hydroxylase deficiency in mild form (M210HD) and in 2 patients with 21-hydroxylase deficiency in classical form (C210HD) and in their parents, in whom a previous HLA,C4,Bf typing demonstrated high prevalence of DR5 and phenotypic absence of fraction C4B of complement (C4BQO). This study contains the evaluation of C3, IgA, IgG, IgM levels, anticardiolipin antibodies (IgG and IgM) and circulating immunocomplexes. A study of lymphocyte subsets was also performed. Among M210HD 1 patient showed presence of anticardiolipin antibodies both IgM and IgG; this patient had shown antinuclear antibodies in a previous stud…
Impaired immune response to Candida albicans in aged mice
2006
The prevalence of opportunistic fungal infections has increased dramatically among the aged population in recent years. This work investigated the effect of ageing on murine defences against Candida albicans. Aged C57BL/6 mice that were experimentally infected intravenously had a significantly impaired survival and a higher tissue fungal burden compared with young mice. In vitro production of tumour necrosis factor (TNF)-α by macrophages from aged mice in response to yeast cells and hyphae of C. albicans was significantly lower than production by macrophages from young mice. In vitro production of cytokines, such as TNF-α and gamma interferon (IFN-γ), by antigen-stimulated splenocytes from …
Induction of tumor-cell lysis by bi-specific antibody recognizing ganglioside GD2 and T-cell antigen CD3
1993
Human tumor cells expressing ganglioside GD2 were lysed by various effector populations targeted with an anti-CD3-anti-GD2 bi-specific antibody (BAb CD3 x GD2). This antibody-heteroconjugate was prepared by chemically cross-linking the OKT-3 monoclonal antibody (MAb) reactive with CD3 antigen on T lymphocytes with the ganglioside MAb ME 361, which binds preferentially to the tumor-associated ganglioside GD2. The specificity of target-cell lysis by the cytotoxic T cells (CTL) was mediated by the specificity of the targeting antibody: GD2-negative cells were not lysed in the presence of the CD3 x GD2 BAb. A dose-dependent response was observed in a range of 10 to 10,000 ng/ml. In contrast, 2 …