213 results about "Peptide antigen" patented technology

Vaccines that target one or more antigens to a cell surface receptor improve the antigen-specific humoral and cellular immune response. Antigen(s) linked to a domain that binds to a cell surface receptor are internalized, carrying antigen(s) into an intracellular compartment where the antigen(s) are digested into peptides and loaded onto MHC molecules. T cells specific for the peptide antigens are activated, leading to an enhanced immune response. The vaccine may comprise antigen(s) linked to a domain that binds at least one receptor or a DNA plasmid encoding antigen(s) linked to a domain that binds at least one receptor. A preferred embodiment of the invention targets HIV-1 env antigen to the CD40 receptor, resulting in delivery of antigen to CD40 positive cells, and selective activation of the CD40 receptor on cells presenting HIV-1 env antigens to T cells.

Disclosed herein are methods and compositions for enhancing the immunogenicity of a preselected protein or peptide antigen in a mammal. Immunogenicity is enhanced by fusing the preselected antigen to an immunoglobulin heavy chain constant region to produce an Fc-antigen fusion protein. The Fc-antigen fusion proteins bind Fc receptors on the surface of antigen presenting cells, thereby targeting the antigen to the antigen presenting cells in the mammal. In addition, disclosed is a family of adjuvants, for example, an Fc-adjuvant fusion protein, for use in combination with the Fc-antigen fusion proteins to enhance or modulate a particular immune response against the preselected antigen.

The invention provides a method for the creation of peptide antigens comprising epitopes with at least a first modification comprising a shortened or lengthened amino acid side chain. By extension or shortening of the side chain with CH3/CH2 groups, for example, made by computer assisted modeling of the tumor antigen (peptide) bound in the MHC-I-groove, immunogenicity can be improved with minimal modification of adjacent tertiary structure, thereby avoiding cross-reactivity. Provided by the invention are methods of creating such antigens, as well as methods for therapeutic or prophylactic treatment of various conditions comprising administration of the antigens.

Methods for desensitising an individual to a selected polypeptide antigen are provided. The methods entail administration of T cell epitope containing peptides from a polypeptide antigen in such a way as to establish a tolergeneic environment, that is, a state of hyporesponsiveness to the peptides. The selected polypeptide antigen is then administered such that the state of hyporesponsiveness and co-administration of the selected antigen are sufficient to desensitise the individual to the polypeptide antigen. Also provided are therapeutic systems useful in the methods of the invention, and the use of polypeptide antigens and peptides in the manufacture of medicaments in the methods of the invention.

Antigen-binding proteins specific for HLA-A2-restricted Wilms tumor 1 peptide are disclosed. The antigen-binding proteins encompass antibodies in a variety of forms, including full-length antibodies, substantially intact antibodies, Fab fragments, F(ab′)2 fragments, and single chain Fv (scFv) fragments, as well as chimeric antigen receptors. Fusion proteins, such as scFv fusions with immunoglobulin or T-cell receptor domains, incorporating the antigen-binding proteins are provided. Methods of using the antigen-binding proteins in the treatment of hyperproliferative diseases such as cancer are also disclosed.

Protein antigens are provided. The protein antigens typically include a peptide antigen conjugated or fused to a chaperone protein to form a “chaperone-antigen” that increases lymph node uptake; improves an immune response; or a combination thereof relative to the peptide antigen alone. The immune response can be, for example, increased antigen-specific proliferation, enhanced cytokine production, stimulation of differentiation and/or effector functions, promotion of survival, rescue from exhaustion and/or anergy of T cells, or a combination thereof. Chaperon-antigens can also be used to induce tolerance and increase immune suppressive responses. In the most preferred embodiments, the peptide antigen is fused to the chaperone protein to form a fusion protein. The “chaperone-antigen” can be combined with an adjuvant to form a vaccine and administered to a subject to modulate an immune response to the antigen. Methods of increasing immune responses, treating cancer and infectious and inducing tolerance are also provided.

Disclosed are compositions and methods for detecting cells or tissue comprising a peptide antigen presented in the context of an MHC or HLA complex. The invention has a wide range of applications including providing a highly sensitive method for detecting cancer cells.

Antigen-specific T cells, including nave T cells, and including rare precursor cells are enriched and expanded in culture. Enrichment and expansion provides a platform for more effective immunotherapy by adoptive transfer, as well as platforms for personalizing immunotherapy by determining T cell reactivity with a library of candidate peptide antigens.

The invention discloses a cyclic chimeric citrullinated peptide antigen and an application thereof. The preparation of the cyclic chimeric citrullinated peptide antigen comprises the following steps: firstly connecting and jogging three small-molecular antigen peptides, namely a citrullinated peptide1, a citrullinated peptide 2 and a citrullinated peptide 3 derived from a silk polymerizing protein/an intermediate filament protein, and then synthetizing a cyclic polypeptide with a similar protein beta-corner structure by forming a disulfide bond through two cysteines inserted into the end N and the end C of a chimeric peptide. The cyclic chimeric citrullinated peptide antigen coats a solid-phase vector to prepare an indirect enzyme linked immunosorbent assay kit used for detecting the hypotype of multiple anti-citrullinated protein antibodies contained in RA (Rheumatoid Arthritis) serum. The cyclic chimeric citrullinated peptide antigen and the ELISA kit thereof which are disclosed by the invention have the advantages of simple preparation and experimental operation process, good result repeatability, qualification or quantification and wide clinical application and scientific research value and are outstandingly enhanced in detection sensibility and diagnosis value on RA compared with an international similar kit.

The invention discloses a C-peptide chemiluminescence immunodetection kit, a preparation method and a detection method therefor, belongs to the field of the immunoassay, and solves the problems of lowsensitivity, long reaction time, and high cost of an existing C-P detection method. The kit comprises magnetic particles coated by the streptavidin; the C peptide antibody labeled by the biotin; theC peptide antibody labeled by the acridinium ester; the wash buffer; the chemoluminescence pre-trigger solution; a calibrator; and a quality control product. The detection method is as follows: the C-peptide antigen in the sample is immunologically reacted with the C-peptide antibody labeled by the biotin and the C peptide antibody labeled by the acridinium ester to form a biotin-C peptide antibody-C peptide antigen-C peptide antibody-acridinium ester solvent; the magnetic particles coated by the streptavidin are combined with the biotin to form a magnetic bead-streptavidin-biotin-C peptide antibody-C peptide antigen-C-peptide antibody-acridinium ester complex; and the concentration of the C peptide is calculated by adding the washing buffer and the like. According to the C-peptide chemiluminescence immunodetection kit, the preparation method and the detection method therefor, the sensitivity is high, the specificity is good, the reaction time is short, and the cost is low.

In a cancer treatment combining cell therapy with chemotherapy, autologous CD8⁺ T cells are obtained from a patient, activated ex vivo by contacting them with xenogenic antigen presenting cells loaded with selected peptide antigen, thereby generating antigen-specific activated cytotoxic T lymphocytes. Such activated CTLs are administered to the patient in conjunction with a lymphodepletion and CTL maintenance regimen comprising a non-myeloblative but lymphdepleting agent, such as cladribine or denileukin diftitox, and interleukin-2 and interferon-α-2b stimulatory cytokines.

MicroRNAs (miRNAs) are a diverse and abundant class of ˜22-nucleotide (nt) endogenous regulatory RNAs that play a variety of roles in animal cells by controlling gene expression at the posttranscriptional level. Increased miR-181a expression in mature T cells is shown to cause a marked increase in T cell activation and augments T cell sensitivity to peptide antigens. Moreover, T cell blasts with higher miR-181a expression become reactive to antagonists. The effects of miR-181a on antigen discrimination are in part achieved by dampening the expression of multiple negative regulators in the T cell receptor (TCR) signaling pathway, including PTPN22 and the dual specificity phosphatases DUSP5 and DUSP6. This results in a reduction in the TCR signaling threshold, thus quantitatively and qualitatively enhancing T cell sensitivity to antigens.

The invention relates to a Qbeta-2aa phage virus-like particle protein which is prepared according to a method comprising the following steps of: (1) mutating a Qbeta phage CP (coat protein) gene terminator codon into a strong terminator codon TAA from TGA and then cloning the strong terminator codon into a protokaryon expression vector pET28a(+) to obtain a coding CP plasmid pETQB-CP; (2) inserting the nucleotides AAGCTT of coding lysine and leucine at the coding immunodominance determining region position in a Qbeta phage CP extension protein gene, i.e. between the 72th codon and the 73th codon of the Qbeta phage CP extension protein gene, and mutating the CP gene terminator codon into GGA from TGA and then cloning the GGA into a protokaryon expression vector PGEX4T-2 to obtain a codingA1 protein plasmid pGEXQbeta-A1; (3) jointly converting the mutated coding Qbeta phage CP plasmid and the A1 protein plasmid into escherichia coli, and inducing and then expressing to obtain the virus-like particle protein Qbeta-2aa; and (4) coupling a short peptide antigen to Qbeta-2aa phage virus-like particles by using a iso-bifunctional cross-linking agent.

IE1 peptide antigens that are recognized by and stimulate production of CMV-specific cytotoxic T lymphocytes are useful for vaccines, in the form of peptides, DNA vaccines or cellular vaccines, and also for diagnostic methods.

The invention relates to the technical field of biomedical diagnostics and discloses a reagent kit for detecting a serum marker of primary hepatic carcinoma, which consists of an ELISA plate enveloped by antigens, an enzyme-labeled antibody working solution, a sample diluent, a washing liquid, positive and negative control serum, a chromogenic solution and a stopping liquid. The reagent kit is characterized in that the envelope antigens of the ELISA plate are five groups of peptide antigens L4-A and L4-B; L7-B; L11-1, L11-3 and L11-4; L12-A and L12-B; and Sui1-A and Sui1-B, which correspond to five serum marker antibodies of the primary hepatic carcinoma; and Sui1-A and Sui1-B respectively. Except the L7B which is separately enveloped, each group of all the other groups of peptide antigens is enveloped by proportionally mixing polypeptides in the same group. Proven by evaluation experiments of the reagent kit and clinical trial, the reagent kit has good specificity and sensitivity, and can be used for early warning prompt or early diagnosis before the primary hepatic carcinoma appears or at early stage of the primary hepatic carcinoma, thereby improving the survival rate of carcinoma patients and evaluating treatment effect and disease outcome in time by observing the dynamic change of related indicators of the serum.

An antibody capable of binding, with a human major histocompatibility complex (MHC)-restricted specificity, a MHC being complexed with an HLA-restricted peptide antigen is provided. The antibody having a binding specificity dictated by at least 4 amino acid residues in said HLA-restricted peptide such that at least 70% reduction in binding of said antibody to said complex is observed when each of said at least 4 amino acid residues is substituted as determined by FACS of cells loaded with said HLA-restricted peptide comprising said substitution, said at least 4 amino acid residues not being anchor residues.

Peptide antigens corresponding to amino acid residues 2-12, 1-12, 2-15 and 1-15 of parathyroid hormone (PTH), antibodies having an affinity to such peptide antigens and methods of producing the same. Such antigens, antibodies and methods producing the same according to the present invention are useful in determining bioactive intact PTH levels in serum, plasma, and/or cell culture media. Such antibodies further possess a high degree of species cross-reactivity, but substantially mitigated cross-reactivity to non-whole PTH peptide fragments and little to no recognition of the first amino acid residue of PTH.

The present embodiments provide for an immunogenic multiple antigen presenting system comprising a polymer to which antigens are associated by complementary affinity molecules. For example, the polymer can be a polysaccharide, or antigenic polysaccharide, to which protein or peptide antigens from the same or different pathogens are indirectly linked. The present immunogenic compositions can elicit both humoral and cellular immune responses to one or multiple antigens at the same time.

The invention relates to a polymer lipid nanoparticle, a preparation method and application thereof as a vaccine adjuvant system. The polymer nanoparticle is a solid sphere composed of a macromoleclar polymer, positively charged cationic lipid is inlaid on the surface, the nanoparticle surface can adsorb protein antigen, polypeptide antigen, viral antigen and other active drugs; the polymer nanoparticle has an average particle size of less than 300nm, a dispersion coefficient, i.e. a PDI (polydispersity) value of less than 0.2, and a Zeta potential average value of greater than 20mV. The polymer nanoparticle provided by the invention has the characteristics of uniform size, high antigen carrying rate, and good maintenance of antigen activity, when the polymer nanoparticle carries an antigen and serves as a vaccine adjuvant, the intake of antigen presenting cells (APCs) to the antigen can be increased, the activation level of antigen presenting cells is improved, and the follow-up immune response level is strengthened.

The invention discloses an amino acid sequence for detecting a tumor marker P16 antigenic epitope and application of the amino acid sequence, and belongs to the technical field of immunology. The invention provides an antigenic amino acid sequence of a tumor anti-cancer gene P16. The P16 polypeptide antigen is used for detecting corresponding specific antigenic epitope in the blood of a patient with lung cancer and esophagus cancer; the antigenic epitope can be used as a tumor marker for estimating the degree of risk for occurring the lung cancer and the esophagus cancer. And the antigenic polypeptide and an antibody thereof can be used for preparing tumor early-diagnosis reagent and developing a targeted drug for treating the tumors.

An amino acid sequence for detecting autoantibody of tumor immune marker BIRC5 and an application belong to the technical field of immunology. The invention provides an antigen amino acid sequence of apotosis inhibition gene BIRC5. A BIRC5 polypeptide antigen is used for detecting corresponding specific autoantibody in blood of lung cancer patients, wherein the autoantibody can be used as a tumor marker for evaluating risk of generation of lung cancer. The polypeptide antigen and an antibody thereof can be used for preparing a tumor early-stage diagnosis reagent and developing a targeted drug which is used for treating tumors.