63 results about "Phage antibody" patented technology

Peripheral blood leucocytes incubated with a semi-synthetic phage antibody library and fluorochrome-labeled CD3 and CD20 antibodies were used to isolate human single chain Fv antibodies specific for subsets of blood leucocytes by flow cytometry. Isolated phage antibodies showed exclusive binding to the subpopulation used for selection or displayed additional binding to a restricted population of other cells in the mixture. At least two phage antibodies appeared to display hithereto unknown staining patterns of B lineage cells. This approach provides a subtractive procedure to rapidly obtain human antibodies against known and novel surface antigens in their native configuration, expressed on phenotypically defined subpopulations of cells. Importantly, this approach does not depend on immunization procedures or the necessity to repeatedly construct phage antibody libraries.

Peripheral blood leucocytes incubated with a semi-synthetic phage antibody library and fluorochrome-labeled CD3 and CD20 antibodies were used to isolate human single chain Fv antibodies specific for subsets of blood leucocytes by flow cytometry. Isolated phage antibodies showed exclusive binding to the subpopulation used for selection or displayed additional binding to a restricted population of other cells in the mixture. At least two phage antibodies appeared to display hithereto unknown staining patterns of B lineage cells. This approach provides a subtractive procedure to rapidly obtain human antibodies against known and novel surface antigens in their native configuration, expressed on phenotypically defined subpopulations of cells. Importantly, this approach does not depend on immunization procedures or the necessity to repeatedly construct phage antibody libraries.

The invention relates to an anti-human TIGIT monoclonal antibody which is particularly related to high-affinity anti-human TIGIT monoclonal antibody with blocking activity. A large-capacity fully-synthetic human phage antibody library is constructed, the specific anti-human TIGIT monoclonal antibody and the high-affinity anti-human TIGIT monoclonal antibody which is optimized after molecular evolution are screened from the human phage antibody library, and the monoclonal antibody comprises a full-human frame region and variable regions of a full-human light chain and a heavy chain.

The invention relates to the technical field of biology and particularly discloses a human anti-CD20 monoclonal antibody and a preparation method and application thereof. In the preparation method, a large-capacity natural human phage antibody library is constructed and the antibody library is screened to obtain a human anti-CD20 antibody 3C5, wherein the amino acid sequence of the heavy chain variable region is shown in SEQ ID NO:6 and the amino acid sequence of the light chain variable region is shown in SEQ ID NO:8. In addition, the invention also discloses a preparation method of the antibody 3C5, a nucleotide sequence coding the antibody 3C5 and an expression vector and host cell containing the nucleotide sequence. Compared with the other anti-CD20 antibodies, the human monoclonal antibody 3C5 has higher antibody affinity and ADCC and CDC activities; and the antibody 3C5 can be used to prepare anticancer medicaments.

The invention discloses a preparation method of an IL-4R resistant single-chain antibody and application of the IL-4R resistant single-chain antibody to tumor resistance. The preparation method comprises the following steps: performing animal immunization, constructing pCANTAB5E-scFv recombinant plasmids, constructing IL-4R resistant antibody libraries, enriching and screening phage antibody libraries, optimizing scFv sequences, constructing pET-32a-scFv recombinant plasmids, performing enzyme digestion and identification on pET-32a-scFv recombinant plasmids, expressing cFv recombination protein, performing SDS-PAGE analysis, performing renaturation and purification on expression protein, performing Western blot analysis and the like. According to the invention, the stable and specific preparation method of the IL-4R single-chain antibody is established and can be used for intervening lung cancers in vivo and in vitro through purification protein, a new experiment basis is provided for treating the lung cancer, and a favorable foundation is laid for further developing of a novel antitumor drug.

The invention relates to a phage antibody library which assembles an ScFv gene fragment between Restriction Enzyme cutting sites of SfiI and NotI of a pCANTAB5E carrier. The phage antibody library is characterized in that the ScFv gene fragment can be affinitive and enriched with antigens of 16-membered macrolide agricultural chemicals to form a soluble single-chain antibody and the phage antibody library is applied to immunoassay of pesticide residue. The phage antibody library has the advantages that the antibody with high affinity can be obtained without animal immunization, the test period is short, the antibody library is the phage antibody library which takes small molecular milbemycin oxime of a 16-membered macrolide generic structure as immunogen to construct, the antibody library theoretically can directly obtain a specific antibody library of 16-membered macrolide compound through screening, the screening flux is high, the efficiency is high, the specificity is strong, and the affinity selecting range is wide, so that the phage antibody library has wide application prospect in the aspects such as agricultural chemical antibody preparation, testing technique development and the like.

The invention relates to the technical field of biomedicine, in particular to an improved anti-VEGFR (vascular endothelial growth factor receptor)-2 monoclonal antibody and application. On the basis of the original research, a new phage antibody library is designed by computer-aided simulation by taking two of them with the highest affinity as templates, and improved heavy chain variable region and light chain variable region amino acid sequences are obtained by multi-round screening; the affinity and biological activity of the anti-VEGFR 2 monoclonal antibody are higher than those of the original antibody. The anti-VEGFR 2 monoclonal antibody obtained by the invention has relatively high affinity, can inhibit the binding of VEGFR-2 and a ligand VEGF thereof in vitro and has good biological activity, and can be used for the treatment of tumors, macular degeneration and other diseases caused by neovascularization.

The invention discloses a fully-humanized anti-human interleukin 17A single-chain antibody, relates to the technical field of genetically engineered antibodies and specifically relates to a fully-humanized antibody fragment which is genetically engineered, screened, expressed and provided with special affinity with interleukin 17A (IL-17A). The genetically engineered antibody fragment is connected with a heavy chain region and a light chain region end to end by virtue of a soft connecting fragment. By constructing a great-capacity natural phage antibody library, an antibody fragment with special adsorption capacity on IL-17A is obtained by biological elutriation. The antibody fragment is constructed into a full-length antibody, so that the reaction of IL-17A on interleukin 6(IL-6) released by a human fibrosarcoma cell HT1080 can be inhibited by virtue of eukaryotic secretory expression and affinity purification. The antibody fragment disclosed by the invention can be used for detecting and treating rheumatoid arthritis.

The invention provides the technical field of antibody medicine, discloses a fully-humanized human anti-IL-1beta monoclonal antibody screened through the phage antibody library technology and prepared through the genetic engineering technology, and discloses a DNA molecule for encoding the monoclonal antibody, a DNA molecule expression carrier for encoding the monoclonal antibody, a host cell and application. The anti-IL-1beta monoclonal antibody can prevent bonding of human IL-1beta and human IL-1R. By means of bonding of IL-1beta, blocking of IL-1beta and a receptor signal channel of the IL-1beta, unnecessary IL-1beta initial induced heat transfer, amplified lymphocyte responses and stimulation acute stage responses can be reduced. The anti-IL-1beta monoclonal antibody can be used for detecting IL-1beta expressions and used for prevention and treatment of cryopyrin-associated periodic syndromes.

The invention relates to a variable region sequence for a novel anti-beta amyloid polypeptide antibody and a coding sequence thereof. The invention utilizes phage display technology to perform multiple screening and enrichment on a human-originated phage single-chain antibody library to obtain phages with Abeta specificity, prepares a phage antibody by culturing the phages, and identifies the acquisition of positive clone. Then an anti-Abeta scFv segment which obtains the solubility is expressed in Escherichia coli, and a corresponding coding sequence of the anti-Abeta scFv segment is obtained through the sequence measurement. Therefore, the invention provides the novel anti-Abeta scFv segment and the coding sequence thereof.

The invention relates to the biotechnology field, and more specifically, the invention discloses a human monoclonal antibody against IgE, a preparation method and a purpose thereof. According to the invention, a natural human phage antibody library of large capacity is constructed;; a human antibody 2E19 strain against IgE is obtained through screening from the library; an amino acid sequence of a heavy chain variable region is expressed as SEQ ID NO: 6; and the amino acid sequence of a light chain variable region is expressed as SEQ ID NO: 8. Besides, the invention also discloses the preparation method of the antibody 2E19, as well as a nucleotide sequence for encoding the antibody 2E19 and an expression vector and a host cell comprising the nucleotide sequence. The antibody 2E19 of the invention has a higher antibody affinity, so as to be able to obviously inhibit degranulation caused by the combination of IgE and FC epsilon RI on a cell surface, and the antibody 2E19 does not combine with the IgE combined with the FC epsilon RI on the cell surface. The antibody 2E19 of the invention could be used for the preparation of a medicine for treating hypersensitivity diseases, especially for treating allergic asthma.

The invention relates to the technical field of genetic engineering, in particular a method for constructing a natural humanized IgG Fab phage antibody library. In the method, Fd genes of the whole set of humanized antibody light chains and antibody heavy chains are amplified from peripheral blood lymphocyte of healthy volunteers by DNA recombinant technology, and are inserted into corresponding positions of phage vector pFabICN so as to construct the natural humanized IgG Fab phage antibody library with high capacity and high variety. Experiments prove that the capacity of the phage antibody library constructed by the method can reach as high as 4*108; and the phage antibody library accords with high-capacity antibody library standard, includes Fd genes of the whole set of humanized antibody light chains and heavy chains, and has high variety. Compared with other phage antibody library constructing methods, the antibody library constructed by the method has the advantages of high capacity and high variety, can be used in low-antigenicity high-compatibility humanized antibody for high-flux screening clinical treatment.

The invention discloses a human source anti-tetanus exotoxin antibody (HTAT-Fab) and preparation method, comprising: constructing human immunity phage antibody bank, screening phage positive clone, further getting HTAT-Fab gene with a specific neutralization activity and high affinity. The gene can be expressed in the procaryotic cell such as E.coli, eukaryotic cell such as microzyme, or mammalian cell such as CHO, purifying to get highly purified HTAT-Fab with a strong tissue penetrability, a high affinity. The HTAT-Fab product can not only eliminate the allergic reaction generated by horse serum anti-tatanus antitoxin (TAT) (foreign protein), but also avoid the blood source for producing human tetanus immunoglobulin (HTIG) and the latent virus pollution.

The invention belongs to the technical field of genetic engineering antibody, and particularly discloses a single-chain antibody C2 of a fully-human anti-human interleukin-21 receptor, and a preparation method and application thereof. The invention also discloses amino acid sequences of immunoglobulin molecules in a heavy chain variable region and a light chain variable region of the C2, including the sequences corresponding to complementarity determining regions CDR1, CDR2 and CDR3. The invention also provides a method for expressing the C2, which comprises the following steps of: screening the single chain antibody C2 of the fully-human anti-human interleukin-21 receptor from a natural human phage antibody library; and obtaining the single chain antibody through secretion and expression of a prokaryotic system, and nickel column affinity chromatography and purification. The single-chain antibody can be specifically bonded to the human interleukin-21 receptor, can inhibit the activation of the interleukin-21 receptor, is applicable to the treatment of interleukin-21 receptor-related diseases including rheumatoid arthritis, autoimmune diseases such as transplantation rejection and other immune system diseases, and also can be coupled with detectable substances and therapeutic agents.

The invention relates to a single-chain antibody capable of specific binding and capable of activating human death receptor 5 (DR5), and belongs to a full-humanized antibody; the single-chain antibody is obtained by performing quintuple screening in a high-capacity full-humanized phage antibody library by using human death receptor DR5 extracellular protein as a target antigen; the single-chain antibody may be acquired by induced expression in Escherichia coli, nickel ion affinity chromatography and molecular-exclusion chromatographic purification; pharmacodynamic experiments prove that the single-chain antibody is efficient in suppressing the growth of DR5 positive colon cancer cell COLO205 and breast cancer cell MDA-MB-231; the single-chain antibody and other antibodies modified therefrom, including full-length, bispecific or fusion protein forms, may act as drugs for positive tumor targeting therapy of death receptor DR5; the single-chain antibody has the advantages such as low immunogenicity, high specificity and high penetrability and is an ideal targeting tumor therapeutic drug.

The present invention provides a preparation method of testicular specific protein 50 humanized single-chain antibody. Said invention utilizes phage antibody presentation technique and adopts the following steps: using human testicular specific protein 50 as target antigen, utilizing immunoaffinity screening process to screen the recombinant phage human antibody variable region gene library, separating and cloning TSP 50 specific single-chain antibody gene AI,AII and C8, then respectively inserting single-chain antibody gene AI, AII and C8 into prokaryotic expression vector PelB, transforming Rosetta microphyte, utilizing IPTG to induce and express exogenous protein, after the thallus is cracked, ulitizing Ni-NTA column affinity chromatography to obtain purified single-chain antibody, utilizing ELISA method to judge that it can be specifically combined with TSP 50 holoprotein and 50 peptide, and using gene engineering measure to massively express said hamonized single-chain antibody. Said invention also discloses application of the testicular specific protein 50 humanized single-chain antibody for diagnosing and curing the diseases of female mammary carcinoma, etc. related to TSP 50.

The invention discloses a preparation method of a human antinuclear antibody, comprising the following steps: collecting single nuclear cells of peripheral blood of a patient with the autoimmune disease, extracting the total RNA (Ribonucleic Acid), and carrying out reverse transcription to obtain a cDNA (Complementary Deoxyribonucleic Acid) library; amplifying a light chain k,1 gene and an immunoglobulin molecule heavy chain Fd gene by taking the acquired cDNA library as a template through a PCR (Polymerase Chain Reaction) method; cloning the light chain k,1 gene into a pComb3Hss carrier to construct a light chain library; loading the heavy chain Fd gene into a carrier to construct and finish a combinatorial library; transforming the obtained recombinant plasmid into escherichia coli XL1-Blue, infecting by using a helper phage M12KO7, and expressing the random combinatorial library on the surface of a filamentous phage to finish phage surface display; and purifying the Fab segment of the human antinuclear antibody by utilizing affinity chromatography. By using the preparation method, the defects that the random combinatorial antibody library has strong randomness, the screening workload is large and a specific antibody is not easy to obtain are overcome, and the specific antibody can be directly screened from a phage antibody library; and in addition, the method is simple and feasible, and the experimental period is shortened.

An antibody or an antibody fragment is provided that is efficacious for treating allergic diseases in which IgE is involved. A human antibody and a fragment thereof to a receptor (FcεRI) having high affinity to Fc portion of IgE was obtained using phage antibody display technique. The human anti-IgE receptor antibody and a fragment thereof of the invention has an activity to inhibit the binding between IgE and IgE receptor and hence is expected to be useful as a medicament for treating allergic diseases caused by the binding between IgE and IgE receptor.

The invention relates to a single-domain antibody of a heparin-binding epidermal growth factor and the application thereof, and belongs to the field of the biological medicine or the biological pharmaceutical technology. According to the technical scheme of the invention, firstly, a strain of single-domain antibody that is high in affinity to HB-EGF is obtained based on the phage antibody library panning and sequencing technology, and then the single-domain antibody is obtained through the expression and purification process of an escherichia coli expression system. Meanwhile, the purified single-domain antibody is applied to the ELISA detection of the HB-EGF and the content detection of the HB-EGF in a sample. The single-domain antibody can inhibit the infiltration and the migration of ovarian cancer cells. The single-domain antibody is easy in mass production, lower in cost and more stable. Therefore, the single-domain antibody has important application value in ELISA and the inhibition of tumors.

The invention relates to the technical field of biological pharmacy, in particular to an obtaining method, a preparing method and a detecting method of a detecting antibody for a CD6-resistant monoclonal antibody T1h. According to the screening technology of a total-synthesis phage antibody library, single-chain antibodies of the antibody T1h are subjected to biopanning, single-chain antibodies of bacteriophage of the antibody T1h are subjected to positive clone identification, gradient-dilution phage ELISA is carried out, the affinity of the single-chain antibodies of the antibody T1h is compared, then all antibodies of the antibody T1h are prepared, and a new specificity monoclonal antibody of the antibody T1h is obtained. A heavy-chain variable region of the antibody comprises the amino acid sequence of SEQ.1, and a light-chain variable region of the antibody comprises the amino acid sequence of SEQ.2. The antibody is used for detecting the concentration of T1h in the blood and other body liquid in the clinical test, the blood concentration of the T1h can be sensitively and rapidly detected, a reliable research method is provided for the clinical test pharmacology and medicine generation analyzing of the T1h, and meanwhile the antibody can be used for neutralizing the T1h antibody.

The invention discloses a human-derived anti-bullous pemphigoid antigen BP180 ScFv; the gene sequence of the BP180 ScFv structurally belongs to the single-chain antibody (scFv) and is composed of a light chain variable region gene and a heavy chain variable region gene. The antibody preparation method mainly comprises the following steps: a, separating the peripheral blood mononuclear cells of bullous pemphigoid patients, extracting the RNA and constructing a phage antibody library through RT-PCR amplification of the antibody light and heavy chain variable region genes; b, selecting the BP180 phage antibodies from the phage antibody library; c, obtaining the human-derived anti-BP180 ScFv of soluble expression through genetic engineering means; d, identifying the binding activity, specificity, affinity and other immunological characteristics of the obtained antibody. The antibody of the invention can block the binding activity between the bullous pemphigoid autoantibody and the corresponding self-antigen and can block the activation of the complement-mediated inflammatory response as a result of the combination of the autoantibodies, and can be used in bullous pemphigoid treatment.

The invention discloses a composite murine hepatitis virus detection kit and a composite murine hepatitis virus detection method. Common specific nucleic acid constant regions of main subtypes of murine hepatitis viruses are selected for designing specific nucleic acid probes; gene sequences of stable regions S2 of common specific structural proteins S of six main subtypes (MHV-1, MHV-2, MHV-3, JHM, A59 and S) of the murine hepatitis viruses are selected for designing primers; nucleic acids of the murine hepatitis viruses are detected by a one-step reverse transcription polymerase chain reaction technique; through gene cloning and expression, S2 proteins of the murine hepatitis viruses are biologically synthesized; specific antigens are used for screening a phage antibody library to obtain corresponding monoclonal antibodies; on the basis, antigens of the murine hepatitis viruses and self-generated antibodies of mice are detected by an enzyme-linked immunosorbent technique. The composite murine hepatitis virus detection kit and the composite murine hepatitis virus detection method have the characteristics of accurate detection result, high sensitivity, high specificity, low cost, simple and convenient in operation and the like.

The invention discloses a preparation method for monoclonal antibodies with functions of anti-tumor angiogenesis. The preparation method comprises the following steps: expression and purification of cell receptor protein VEGFR2, preparation of completely humanized phage Fab antibody libraries, selection of antibodies with high affinity from the phage antibody libraries, immobilization of purified VEGFR2 on CM5 chips of Biacore, testing of association rates and dissociation rates of AVR2 antibodies with different concentrations and VEGFR2 respectively, selection of antibody libraries based on high affinity and high specificity of antibodies and antigens, cloning of antibody genes to expressing cells, construction of engineered cell lines with high expression level, and detection and evaluation of anti-angiogenesis. By utilizing the phage antibody library technology, the preparation method can produce humanized antibodies directly. In addition, the monoclonal antibodies are advantaged by strong drug specificity, minimal side effects and remarkable effects.

The invention discloses a method utilizing phage antibody library to screen human histamine receptor 4 (HR4) epitope mimic peptide and a vaccine construction method thereof. A phage random dodecapeptide library is utilized to screen one polypeptide section, and the amino acid sequence of the polypeptide section is FNKWMDCLSVTH. The provided method utilizes a phage random dodecapeptide library technology to screen the polypeptide sequence of HR4 epitope mimic peptide; ELISA identifies the affinity of phage monoclone on HR4 mono-antibody, then sequencing is carried out to obtain one polypeptide sequence, which is names as PT1; the targeting result of phage positive clone is further identified to indicate that phage positive clone can specifically combine the human HR4 monoclonal antibody; the human HR4 monoclonal antibody specific polypeptide can be obtained through screening; thus the HR4 epitope mimic peptide vaccine can be constructed; and the vaccine on the basis of HR4 mimic epitope can be used to treat allergic rhinitis in clinic, can also be applied to the research on HR4 antagonist, and provides primary experimental references for the construction of HR4 antagonist.

The invention provides a monocytic leukemia associated antigen MLAA-34 resistant fully human monoclonal single-chain antibody ScFv. The monoclonal single-chain antibody ScFv of special anti-MLAA-34 is obtained by screening and identifying in a phage antibody library; MLAA-34 protein is firstly expressed and purified, and antigen protein is provided for monoclonal antibody preparation. A method beneficial to genetic engineering is used for screening and identifying anti-MLAA-34 fully human monoclonal antibody. The fully human monoclonal single-chain antibody ScFv for specially combining and efficiently expressing tumor cell strains of MLAA-34 is obtained. The fully human monoclonal single-chain antibody ScFv can be used for solving the immunogenicity problem of a mouse original antibody, and the single-chain antibody ScFv is formed by connecting a heavy chain and a light chain of an antibody variable region, is small in molecular weight, is high in penetrating power and is more beneficial to application.

The invention discloses a preparation method and application of a human-derived VVH resistant antibody. The human-derived VVH resistant antibody is a human-derived antibody and has the capacity of neutralizing VVH. The VVH resistant antibody provided by the invention comprises a light chain variable region and a heavy chain variable region, wherein the amino acid sequence of the heavy chain variable region is 135th-260th amino acid residues from an amino terminal in the sequence 3 in a sequence table; the amino acid sequence of the light chain variable region is 1st-113th amino acid residues from the amino terminal in the sequence 3 in the sequence table. According to the antibody disclosed by the invention, immobilized VVH is used as an antigen, and a constructed human-derived natural high-capacity phage antibody library is used, so that the human-derived VVH resistant antibody is successfully screened, and through ELISA identification, the VVH resistant antibody has good specificity, and has a wide application prospect in treatment of vibrio infection.

The invention discloses a method for screening an estrogen receptor Alpha (ER Alpha) single-chain antibody with a phage antibody library. The method comprises the following steps: using an ER Alpha protein as an immunogen for immunizing a New Zealand white rabbit and extracting total RNA of spleen; amplifying VH and VL fragments by RT-PCR, and splicing an scFv gene; constructing a PCANTAB5E-ScFv recombinant plasmid, electrotransforming E. coli TG1 competent cells with the recombinant plasmid to construct a phage single-chain antibody library; using ER Alph-positive breast cancer tissue sections and ER Alpha protein as solid phase antigens for performing affinity enrichment screening on the antibody library; and identifying positive clones with a method of combining a Phage-ElLSA method with breast cancer cell smear immunochemistry. The invention establishes a method for specifically screening ER from the phage antibody library by using the ER Alpha -positive breast cancer tissue sections, and identifying the positive clones with the method of combining the Phage-ElLSA method with the breast cancer cell smear immunochemistry, and provides a new idea for a phage antibody library screening method.

The invention relates to an antibody library. An immune globulin light chain variable region VL gene sequence is inserted between Xba and Sac restriction enzyme cutting sites of a Pcomb3 vector. An immune globulin heavy chain variable region VH gene sequence is inserted between Spe and Xho endo restriction enzyme cutting sites. The antibody library is characterized in that two gene fragments comprise the possible combination of antibody variable region light chain and heavy chain, and the antibody library can realize affinity enrichment with an avian influenza virus antigen, and can be applied to avian influenza immunodetection. The antibody library has the advantages that a high affinity antibody can be acquired without animal immunity; a preparation period is short; the antibody library is a phage antibody library which is constructed by taking mice natural immune globulin variable region light chain and heavy chain genes as sources, theoretically contains all possible antibodies in a mice, and is a specificity antibody library which can directly acquire different avian influenza viruses through screening; and the screening has the advantages of high efficiency, high flux, large selection base and high specificity, thus the phage antibody library has a wide application prospect in the aspect of the disease detection of avian influenza and other animals.