Search results for "Immunodominant Epitopes"
showing 10 items of 20 documents
Behavior of a Short preS1 Epitope on the Surface of Hepatitis B Core Particles
1999
The major immunodominant region of hepatitis B core particles is widely recognized as the most prospective target for the insertion of foreign epitopes, ensuring their maximal antigenicity and immunogenicity. This region was mapped around amino acid residues 79-81, which were shown by electron cryo-microscopy to be located on the tips of the spikes protruding from the surface of hepatitis B core shells. Here we tried to expose a model sequence, the short immunodominant hepatitis B preS1 epitope 31-DPAFR-35, onto the tip of the spike, with simultaneous deletion of varying stretches from the major immunodominant region of the HBc molecule. Accessibility to the monoclonal anti-preS1 antibody M…
Interaction of wild-type and naturally occurring deleted variants of hepatitis B virus core polypeptides leads to formation of mosaic particles
2000
AbstractThe simultaneous presence of hepatitis B virus (HBV) genomes carrying wild-type (wt) and in-frame deleted variants of the HBV core gene has been identified as a typical feature of HBV-infected renal transplant patients with severe liver disease. To investigate possible interactions of wt and deleted core polypeptides a two-vector Escherichia coli expression system ensuring their concomitant synthesis has been developed. Co-expression of wt and a mutant core lacking 17 amino acid residues (77–93) within the immunodominant region led to the formation of mosaic particles, whereas the mutant alone was incapable of self-assembly.
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…
Leucine aminopeptidase is an immunodominant antigen of Fasciola hepatica excretory and secretory products in human infections.
2007
ABSTRACT The liver fluke Fasciola hepatica parasitizes humans and ruminant livestock worldwide, and it is now being considered a reemerging zoonotic disease, especially in areas in which it is endemic, such as South America. This study investigates the immune response to excretory and secretory products produced by F. hepatica in a group of patients from the Peruvian Altiplano, where the disease is highly endemic. Using a proteomic approach and immunoblotting techniques, we have identified the enzymes leucine aminopeptidase (LAP) and phosphoenolpyruvate carboxykinase as immunodominant antigens recognized by sera from fasciolosis patients. An indirect enzyme-linked immunosorbent assay using …
Antigen processing influences HIV-specific cytotoxic T lymphocyte immunodominance
2016
Udgivelsesdato: 2009-May-03 Although cytotoxic T lymphocytes (CTLs) in people infected with human immunodeficiency virus type 1 can potentially target multiple virus epitopes, the same few are recognized repeatedly. We show here that CTL immunodominance in regions of the human immunodeficiency virus type 1 group-associated antigen proteins p17 and p24 correlated with epitope abundance, which was strongly influenced by proteasomal digestion profiles, affinity for the transporter protein TAP, and trimming mediated by the endoplasmatic reticulum aminopeptidase ERAAP, and was moderately influenced by HLA affinity. Structural and functional analyses demonstrated that proteasomal cleavage 'prefer…
A molecular assembly system that renders antigens of choice highly repetitive for induction of protective B cell responses.
2002
Virus like particles (VLPs) are known to induce potent B cell responses in the absence of adjuvants. Moreover, epitope-specific antibody responses may be induced by VLPs that contain peptides inserted in their immunodominant regions. However, due to steric problems, the size of the peptides capable of being incorporated into VLPs while still permitting capsid assembly, is rather limited. While peptides genetically fused to either the N- or C-terminus of VLPs present fewer assembly problems, the immune responses obtained against such epitopes are often limited, most likely because the epitopes are not optimally exposed. In addition, such particles may be less stable in vivo. Here, we show th…
Control of murine cytomegalovirus in the lungs: Relative but not absolute immunodominance of the immediate-early 1 nonapeptide during the antiviral c…
1998
Effective control by the immune system is a hallmark of cytomegalovirus (CMV) infection. Accordingly, human CMV disease is a medical problem restricted to the immunologically immature or immunocompromised host (for a review, see reference 21). Murine models have implicated natural killer (NK) cells and CD8 T cells in the control of CMV infection. While NK cells mediate early protection in genetically resistant mouse inbred strains (4, 5, 31, 51), CD8 T cells establish enduring protective memory and function as principal antiviral effectors in susceptible strains (31). Specifically, in the BALB/c strain, major histocompatibility complex (MHC) class I-restricted antiviral CD8 T cells resolve …
Human leucocyte antigen-A2 restricted and Mycobacterium tuberculosis 19-kDa antigen-specific CD8+ T-cell responses are oligoclonal and exhibit a T-ce…
2001
CD8+ T cells can be grouped into two different types of secretory T lymphocytes, based on the cytokine-secretion pattern upon antigen exposure: those with a T-cell cytotoxic type 1 response (Tc1), which secrete interferon-gamma (IFN-gamma), or those with a T-cell cytotoxic type 2 response, which secrete interleukin (IL)-4 and IL-10. We examined the CD8+ T-cell response directed against an immunodominant human leucocyte antigen (HLA)-A2-presented peptide derived from a 19-kDa Mycobacterium tuberculosis-associated antigen. T cells were examined by functional analysis and by T-cell receptor (TCR) complementarity-determining region 3 (CDR3)-spectratyping, which defines the complexity of a T-cel…
Quantitation of antigen-reactive T cells in peripheral blood by IFNgamma-ELISPOT assay and chromium-release assay: a four-centre comparative trial
2000
The ELISPOT assay is increasingly being used for the monitoring of the induction of antigen-reactive T cells in cancer vaccination trials. In order to evaluate the reliability of T cell frequency analysis with the ELISPOT assay, a comparative study was performed in four European laboratories. Six samples from healthy subjects were analyzed for the frequency of influenza-reactive CD8+ T cells in peripheral blood mononuclear cells (PBMC) by IFNgamma-ELISPOT assay. In addition, one laboratory determined cytotoxic T cell precursor (CTL) frequencies in these samples by limiting dilution chromium-release assay (LDA), and three laboratories performed a variant of the LDA, the multiple microculture…
Quantitative Prediction of the Landscape of T Cell Epitope Immunogenicity in Sequence Space
2019
Immunodominant T cell epitopes preferentially targeted in multiple individuals are the critical element of successful vaccines and targeted immunotherapies. However, the underlying principles of this "convergence" of adaptive immunity among different individuals remain poorly understood. To quantitatively describe epitope immunogenicity, here we propose a supervised machine learning framework generating probabilistic estimates of immunogenicity, termed "immunogenicity scores," based on the numerical features computed through sequence-based simulation approximating the molecular scanning process of peptides presented onto major histocompatibility complex (MHC) by the human T cell receptor (T…