Search results for "epitope"
showing 10 items of 455 documents
Functional Definition of a B Cell Epitope, KGEQGEPGA, on C1q the Fc-Binding Subunit of the First Component of Complement
1999
A synthetic peptide representing the C1q epitope KGEQGEPGA has been shown to suppress or delay the onset of CII-induced arthritis when applied intravenously (i.v.) prior to an intradermal (i.d.) challenge, in a mouse model; the phenomenon being associated with the development of immunoglobulin (Ig)M antibodies specific for the KGEQGEPGA epitope. Here we show that this amino acid sequence provides an immunodominant B cell epitope that is recognised by autoantibodies present in the sera of patients with chronic inflammatory diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis, two diseases associated with an immune response to C1q. The peptide's ability to produce pept…
Inducible lectins with galectin properties and human IL1alpha epitopes opsonize yeast during the inflammatory response of the ascidian Ciona intestin…
2007
Studies on inducible ascidian lectins may shed light on the evolutionary emergence of cytokine functions. Here, we show that the levels of opsonins, with IL1alpha-epitopes, increase in Ciona intestinalis hemolymph as a response to an inflammatory stimulus and, in particular, to intratunic injection of lipopolysaccharide (LPS). The inflammatory agent promptly (within 4 h) enhances Ca(2+)-independent serum hemagglutinating and opsonizing activities, which are both inhibited by D-galactose and D-galactosides (alpha-lactose, N-acetyl-D-lactosamine, thio-digalactoside), suggesting that anti-rabbit erythrocyte lectins with galectin properties are involved as opsonins. Inducible galectin molecules…
First Evidence for a Covalent Linkage between Enterobacterial Common Antigen and Lipopolysaccharide in Shigella sonnei Phase II ECALPS
2014
Enterobacterial common antigen (ECA) is expressed by Gram-negative bacteria belonging to Enterobacteriaceae, including emerging drug-resistant pathogens such as Escherichia coli, Klebsiella pneumoniae, and Proteus spp. Recent studies have indicated the importance of ECA for cell envelope integrity, flagellum expression, and resistance of enteric bacteria to acetic acid and bile salts. ECA, a heteropolysaccharide built from the trisaccharide repeating unit, →3)-α-D-Fucp4NAc-(1→4)-β-D-ManpNAcA-(1→4)-α-D-GlcpNAc-(1→, occurs as a cyclic form (ECA(CYC)), a phosphatidylglycerol (PG)-linked form (ECA(PG)), and an endotoxin/lipopolysaccharide (LPS)-associated form (ECA(LPS)). Since the discovery of…
The amide of galacturonic acid with lysine as an immunodominant component of the lipopolysaccharide core region from Proteus penneri 42 strain
2014
Most Proteus lipopolysaccharides (LPSs) contain uronic acids or their amides with different amino acids, which together with other negatively charged components account for the acidic character of such LPS molecules. Previous studies have shown the significance of an amide of galacturonic acid with lysine [D-GalA(L-Lys)] for serological specificity of O-antigens from few P. mirabilis strains. In this work, the immunodominant role of GalALys was indicated for the P. penneri 42 LPS core region. The studies also showed the serological identity of core oligosaccharides from P. penneri 42 (O71), P. mirabilis 51/57 (O28) and R14/S1959 strains. from P. penneri 42 (O71), P. mirabilis 51/57 (O28) an…
Cationic Nanohydrogel Particles for Therapeutic Oligonucleotide Delivery.
2017
Short pharmaceutical active oligonucleotides such as small interfering RNA (siRNA) or cytidine-phosphate-guanosine (CpG) are considered as powerful therapeutic alternatives, especially to medicate hard-to-treat diseases (e.g., liver fibrosis or cancer). Unfortunately, these molecules are equipped with poor pharmacokinetic properties that prevent them from translation. Well-defined nanosized carriers can provide opportunities to optimize their delivery and guide them to their site of action. Among several concepts, this Feature Article focuses on cationic nanohydrogel particles as a universal delivery system for small anionic molecules including siRNA and CpG. Cationic nanohydrogels are deri…
Deficient cytokine response of human allergen-specific T lymphocytes from humanized SCID mice and reconstitution by professional antigen-presenting c…
2000
Abstract Background: Hu-PBL-SCID mice generated by the transfer of PBMCs from atopic individuals may provide a physiologic in vivo model for investigating human responses to allergens and potential approaches toward immunotherapy. Objective: This study was undertaken to investigate the functional activity and cytokine profile of human allergen-reactive T lymphocytes isolated from hu-PBL-SCID mice. Methods: PBMCs from allergic individuals were coinjected with allergen into SCID mice. Human lymphocyte migration and phenotype were established by reverse transcription–PCR and immunohistochemistry, IgE levels in sera were determined, and the frequency of allergen-reactive cytokine-producing T ly…
Processing and Presentation of Protein and Parasite-Derived Antigens by 4F7+ Dendritic Cells
1995
The dendritic cell (DC), a trace component of splenocytes is the principal cell type required for a primary mixed lymphocyte reaction.1 Splenic DC are described as antigen presenting cells (APC) capable to generate immunogenic fragments of intact protein antigens for presentation to MHC class II restricted T cells,2 in contrast to former findings.3 Langerhans cells (LC) as potent APC are members of the dendritic cell lineage forming a system of potent APC, first identified by Steinman and Conn.4 Importanly Schuler and Steinman have subsequently presented experimental evidence suggesting that LC represent immature DC.3 During infectious diseases caused by parasites of the genus Leishmania LC…
Exploring the MHC-peptide matrix of central tolerance in the human thymus
2013
Ever since it was discovered that central tolerance to self is imposed on developing T cells in the thymus through their interaction with self-peptide major histocompatibility complexes on thymic antigen-presenting cells, immunologists have speculated about the nature of these peptides, particularly in humans. Here, to shed light on the so-far unknown human thymic peptide repertoire, we analyse peptides eluted from isolated thymic dendritic cells, dendritic cell-depleted antigen-presenting cells and whole thymus. Bioinformatic analysis of the 842 identified natural major histocompatibility complex I and II ligands reveals significant cross-talk between major histocompatibility complex-class…
Xid-defective male (CBA/N x C57BL/6)F1 accessory cells present bovine insulin to long-term cultured F1-restricted T-cells
1982
The reactivity of H-2b-restricted murine T cells towards bovine insulin was reported to depend on the expression of Ia. W39, a private specificity of I-Ab, on antigen-presenting cells. Cells of male (CBA/N X B6)F1 mice carrying the mutation xid on the X chromosome lack IA. W39 on the cell surface. These cells are unable to present bovine insulin to primed T cells derived from female (CBA/N X B6)F1 mice. We show here that spleen cells of male (CBA/N X B6)F1 hybrids served perfectly as accessory cells for the insulin-dependent induction of a proliferative response of long-term cultured T cells with (B10 X B10.BR)F1 genotype, restricted to recognizing insulin in the context of F1-unique I-A de…
Effects of Presynaptic Mutations on a Postsynaptic Cacna1s Calcium Channel Colocalized with mGluR6 at Mouse Photoreceptor Ribbon Synapses
2008
Purpose Photoreceptor ribbon synapses translate light-dependent changes of membrane potential into graded transmitter release via L-type voltage-dependent calcium channel (VDCC) activity. Functional abnormalities (e.g., a reduced electroretinogram b-wave), arising from mutations of presynaptic proteins, such as Bassoon and the VDCCalpha1 subunit Cacna1f, have been shown to altered transmitter release. L-type VDCCalpha1 subtype expression in wild-type and mutant mice was examined, to investigate the underlying pathologic mechanism. Methods Two antisera against Cacna1f, and a Cacna1f mouse mutant (Cacna1fDeltaEx14-17) were generated. Immunocytochemistry for L-type VDCCalpha1 subunits and addi…