274 results about "Cell fusion" patented technology

The invention discloses a human SARS-CoV-2 monoclonal antibody. The preparation method of the human SARS-CoV-2 monoclonal antibody comprises the steps: adopting SARS-CoV Nucleocapsid recombinant protein as immunogen, immunizing BALB/c mice, performing fusion and subcloning on spleen cells and myeloma cells of mice, then performing a large amount of repeated screening and domestication of cell lines through commercialized products SARS-CoV-2 Nucleocapsid and MERS Nucleocapsid so as to obtain a hybridoma cell line capable of secreting the SARS-CoV-2-resistant N monoclonal antibody with high affinity and high specificity finally and successfully, and finally performing ascites preparation and purification so as to obtain the monoclonal antibody, wherein the amino acid sequence of the SARS-CoVNucleocapsid recombinant protein is shown in SEQ ID No. 1. The invention also discloses application of the monoclonal antibody in preparation of SARS-CoV-2 virus detection products and preparation ofdrugs for inhibiting the SARS-CoV-2 viruses. The monoclonal antibody can be used for detecting the SARS-CoV-2 in human throat swabs/pulmonary secretions and other samples by using a double-antibody sandwich method, and can be applied to diagnosis and prevention and control of SARS-CoV-2 virus infection and scientific researches of viruses and other study.

The invention discloses a human fat mesenchymal stem cell extract and lyophilized powder and applications thereof. The human fat mesenchymal stem cell extract is prepared by the steps: collecting subcultured P3-P30 generations of human fat mesenchymal stem cells, culturing with cell growth liquid until 80% of cells are fused, removing culture liquid, washing the cells with a phosphate buffer solution for three times, adding into a serum-free culture solution, continuously culturing for 72 hours, collecting the serum-free culture solution, digesting uncollected cells with a digestion solution, crushing the cells with an ultrasonic crushing device, centrifuging, and then collecting supernatant; and mixing the collected serum-free culture solution and the collected supernatant, filtering, collecting filtrate, concentrating, and sterilizing. The human fat mesenchymal stem cell extract and the lyophilized powder thereof have multiple biological activities, can be used for preparing wound healing or cell repair medicaments and other biopharmaceutical products, and can also be used for preparing whitening products or skin anti-wrinkle products and other fine chemical products.

A single chain, polypeptide fusion protein, comprising: a non-cytotoxic protease, or a fragment thereof, which protease or protease fragment is capable of cleaving a protein of the exocytic fusion apparatus of a nociceptive sensory afferent; a dynorphin Targeting Moiety that is capable of binding to a Binding Site on the nociceptive sensory afferent, which Binding Site is capable of undergoing endocytosis to be incorporated into an endosome within the nociceptive sensory afferent; a protease cleavage site at which site the fusion protein is cleavable by a protease, wherein the protease cleavage site is located between the non-cytotoxic protease or fragment thereof and the dynorphin Targeting Moiety; and a translocation domain that is capable of translocating the protease or protease fragment from within an endosome, across the endosomal membrane and into the cytosol of the nociceptive sensory afferent. Nucleic acid sequences encoding the polypeptide fusion proteins, methods of preparing same and uses thereof are also described.

This invention provides: agents determined to be capable of specifically inhibiting the fusion of a macrophage-tropic primary isolate of HIV-1 to a CD4⁺ cell, but not a T cell-tropic isolate of HIV-1 to a CD4⁺ cell; and agents determined to be capable of specifically inhibiting the fusion of a T cell-tropic isolate of HIV-1 to a CD4⁺ cell, but not a macrophage-tropic primary isolate of HIV-1 to a CD4⁺ cell. This invention also provides: agents capable of specifically inhibiting the fusion of a macrophage tropic primary isolate of HIV-1 with a CD+ cell susceptible to infection by a macrophage-tropic primary isolate of HIV-1; and agents capable of specifically inhibiting the fusion of a T cell-tropic isolate of HIV-1 with a CD4⁺ cell susceptible to infection by a T cell-tropic isolate of HIV-1. The agents include but are not limited to antibodies. This invention further provides: methods of inhibiting fusion of a macrophage-tropic primary isolate of HIV-1 with a CD+ cell susceptible to infection by a macrophage-tropic primary isolate of HIV-1 which comprises contacting the CD4⁺ cell with an amount of an agent capable of specifically inhibiting such fusion so as to thereby inhibit such fusion; and methods of inhibiting fusion of a T cell-tropic isolate of HIV-1 with a CD4⁺ cell susceptible to infection by a T cell-tropic isolate of HIV-1 which comprises contacting the CD4⁺ cell with an amount of an agent capable of specifically inhibiting such fusion so as to thereby inhibit such fusion.

This invention provides an antibody capable of specifically inhibiting the fusion of an HIV-1 envelope glycoprotein⁺ cell with an appropriate CD4⁺ cell without cross reacting with the HIV-1 envelope glycoprotein or CD4 and capable of inhibiting infection by one or more strains of HIV-1. This antibody is then used to identify a molecule which is important for HIV infection. Different uses of the antibody and the molecule are described.

The potential of a stem cell to differentiate into specialized cell types for restoring normal tissue/organ function has stimulated interest in stem cell research. The methods used to coax stem cells differentiate into specialized cells still remain in their infancy stages. The disclosed invention is the generation of mammalian or avian cell hybrids formed from fusing lineage committed somatic cells with nucleated stem cells or nucleated transit amplifying cells. The fusion of lineage committed somatic cells with nucleated stem cells, or nucleated transit amplifying cells as described herein facilitates stem cell differentiation and lineage commitment of hybrid cells and can be aided by inclusion of an encapsulation step. By the fusion of cells in this invention, this invention also provides for methods to restore damaged tissue or the expression of defective, dysfunctional, decreased, lost or not previously expressed bio-pharmaceutical products.

This invention provides a composition which comprises an admixture of three compounds, wherein: (a) one compound is an antibody which binds to a CCR5 receptor; (b) one compound retards attachment of HIV-1 to a CD4+ cell by retarding binding of HIV-1 gp120 envelope glycoprotein to CD4 on the surface of the CD4+ cell; and (c) one compound retards gp41 from adopting a conformation capable of mediating fusion of HIV-1 to a CD4+ cell by binding noncovalently to an epitope on a gp41 fusion intermediate; wherein the relative mass ratio of any two of the compounds in the admixture ranges from about 100:1 to about 1:100, the composition being effective to inhibit HIV-1 infection of the CD4+ cell. This invention also provides a method of inhibiting HIV-1 infection of a CD4+ cell which comprises contacting the CD4+ cell with an amount of the composition of the subject invention effective to inhibit HIV-1 infection of the CD4+ cell so as to thereby inhibit HIV-1 infection of the CD4+ cell.

The invention relates to a preparation method of HRPII protein monoclonal antibody of plasmodium falciparum. The preparation method comprises the following steps of: adopting HRPII protein of plasmodium falciparum as target antigen and respectively analyzing and selecting two dominant antigen epitopes of A and B; respectively repeating the two dominant antigen epitopes of A and B, then continuously connecting four glycine and forming recombinant protein C; adopting most securest code of escherichia coli and converting the amino acid sequence of the recombinant protein C into corresponding nucleotide sequence; carrying out chemical synthesis to the former step to obtain the nucleotide sequence, and respectively adding enzyme cutting sites BamHI and EcoRI at the upstream and downstream thereof; inserting nucleotide fragment obtained by the former step into expression carrier PET-28a(+), constructing recombinant protein C expression carrier and inducing to express the recombinant proteinC in the escherichia coli BL21 (DE3); carrying out ultrasonic bacteria breaking and low-temperature centrifugation, then taking supernatant of the solution, affining a chromatographic column by nickel-agarose, eluting and obtaining purified recombinant protein C; after immunizing Balb/c mouse with the recombinant protein C for a plurality of times, taking and fusing spleen cells with sp2/0 myelomacells, and obtaining six hybridoma cell lines by multiple rounds of screening; and purifying monoclonal antibody, respectively marking horse radish peroxidase and prorating matching and combination of optimum monoclonal antibody by ELISA orthogonal experiment.

This invention provides a method for establishing hetero-hybrid tumor engineering cell sequence for producing human monoclonal antibody for anti-hepatitis B virus. The anti-HBs positive human splenic lymph cell (SL) is fused with mouse plasmacytoma sequence P3-X63/Ag8-653 cell. Limiting dilution method is used for cloning the positive antibody poro-hybrid-tumor cell to obtain hetero hybrid tumor engineering cell sequence which produces human monoclonal antibody for anti-hepatitis B virus, with stable and high product, rate. Said monoclonal antibody is proceeded with purification and cross-linkage with interferon to produce target prepn. of anti-hepatitis B virus human monoclonal antibody crosslinking with itnerferon, and passive immune prepn. for hepatitis B, and testing agent for hepatitis B.

The invention relates to a hybridoma cell strain secreting thiamethoxacin monoclonal antibody and application thereof, belonging to the field of food safety immunodetection. The accession number of the hybridoma cell strain is CGMCC No. 14699. According to the invention, a complete Freund's adjuvant is used for primary immunization of a BALB/c mouse, then an incomplete Freund's adjuvant is used for booster immunization three times, and a thiamethoxam complete antigen containing no adjuvant is used for impact immunization once, so the BALB/c mouse is immunized; and then the high-titer low-IC50spleen cells of the immunized mouse are fused with mouse myeloma cells by using a PEG method, and then the cell strain is obtained through indirect competitive ELISA screening and subcloning three times. The monoclonal antibody secreted by the cell strain has good specificity and detection sensitivity (with an IC50 value of 0.81 ng/mL) to thiamethoxam and can be used for detection of thiamethoxamresidues in food.

The invention belongs to the field of use of a stem cell conditioned medium in medicinal cosmetics, and especially relates to an application of the conditioned medium in skin ageing resistance. Researches find that a large amount of complex active substances secreted by stem cells are stored in a medium in the in vivo culture process of mesenchymal stem cells, and is called as the stem cell conditioned medium, and an obtaining method of the medium comprises the following steps: carrying out digestive passage on p2 generation mesenchymal stem cells by using 0.05% pancreatin, inoculating 2*10<6> into a 150mm culture dish, and culturing to obtain p3 generation cells; and sucking the obtained culture supernatant when 80% of the p3 generation cells fuse, washing by using PBS twice, adding a new serum-free medium, putting the obtained cells in a 37DEG C 5% CO2 incubator, culturing for 48h, and collecting the obtained culture supernatant to obtain the stem cell conditioned medium. The stem cell conditioned medium obtained in the invention can supplement skin cell metabolism promotion substances lacked in skins and also can induce new collagen synthesis in order to maintain elasticity of skins and reduce wrinkles.

The invention discloses a tissue culturing method for sugarcane seeds. The seed of the general sugarcane is directly the tail in the sugarcane or just the whole sugarcane. If the seeds are kept for a plurality of years, various germs and viruses intrude into the body to cause degeneration of the breed and continuous reduction of the yield. The general method for selecting high-quality seed of the sugarcane is to select variation strains for high-quality seed breeding, so the yield is not increased so greatly. The existing hybrid sugarcane is obtained by hybridizing different well-bred sugarcanes, so the hybrid sugarcane breed is generally hard to embody excellent quality. The tissue culturing method for sugarcane seeds uses cell tissues of bamboo shoots, stevia rebaudiana and sugarcane for cell fusion hybridization, so that the hybrid sugarcane seed prepared by the method disclosed by the invention is characterized by growing strongly, resisting drought, flood, falling, bad environment, diseases and insect pests, and having high immunocompetence. The hybrid sugarcane grows quickly like bamboo shoots and also has the character that the sweet taste of the stevia rebaudianum is better than the sweet taste of the sugarcane, so that the hybrid sugarcane seed prepared by the method disclosed by the invention uniquely has the character of excellent hybrid quality.

The invention provides a rabbit-derived immortal B-lymphocyte capable of fusion with a rabbit splenocyte to produce a hybrid cell that produces an antibody. The immortal B-lymphocyte does not detectably express endogenous immunoglobulin heavy chain and may contain, in certain embodiments, an altered immunoglobulin heavy chain-encoding gene. A hybridoma resulting from fusion between the subject immortal B-lymphocyte and a rabbit antibody-producing cell is provided, as is a method of using that hybridoma to produce an antibody. The subject invention finds use in a variety of different diagnostic, therapeutic and research applications.

The invention provides an anti-aflatoxin general type monoclonal antibody hybridoma cell line and application thereof, belonging to the field of food safety immunodetection. The cell line 1G6 provided by the invention is collected in the China General Microbiological Culture Collection Center (CGMCC) with a collection number of CGMCC No.7210. After an aflatoxin complete antigen is uniformly mixed with equivalent Quick Antibody immunologic adjuvant TM, an obtained mixture is injected to immunize BALB/c mice through leg muscle. B1-KLH (fumonisin B1-Keyhole Limpet Hemocyanin) is adopted for the first time of immunization, M1-KLH (fumonisin M1-Keyhole Limpet Hemocyanin) is adopted for the second time of immunization, and an M1 complete antigen (without containing adjuvant) is adopted for the last time of impaction immunization. Splenocytes of immunized mice are fused with myeloma cells through a PEG (polyethylene glycol) method, and the hybridoma cell line 1G6 is obtained through indirect ELISA (Enzyme-Linked Immuno Sorbent Assay) and indirect competence ELISA screening and three times of subcloning. A monoclonal antibody secreted from the cell line has better affinity and detection sensitivity for aflatoxins B1, B2, G1, G2 and M1, and can be used for immunodetection of the total quantity of the aflatoxins in the food safety.

The invention discloses an anti-human CEACAM5 monoclonal antibody and a preparation method and application thereof, and the anti-human CEACAM5 monoclonal antibody is produced by a mouse hybridoma cellline with the accession number CCTCC NO: C2016129. The preparation method comprises the following steps: S1, immunizing a mouse with whole cell protein, lysed by human gastric cancer cells, as an immunogen; S2, fusing spleen cells of the immunized mouse obtained in the step S1 with mouse myeloma cells; S3, selecting a hybridoma cell line stably secreting antibodies after cell cloning occurs during the cell fusing in the step 2; and S4, preparing the anti-human CEACAM5 monoclonal antibody from the hybridoma cell line stably secreting the antibodies obtained in the step 3. The monoclonal antibody can be used to prepare a composition for treating a malignant tumor. The anti-human CEACAM5 monoclonal antibody can be widely used in various routine operations such as flow cytometry, immunohistochemical staining and immunoprecipitation.

The present invention is directed to non-cytotoxic protein conjugates for inhibition or reduction of exocytic fusion in a nociceptive sensory afferent cell. The protein conjugates comprise: (i) a Targeting Moiety (TM), wherein the TM is an agonist of a receptor present on a nociceptive sensory afferent cell, and wherein the receptor undergoes endocytosis to be incorporated into an endosome within the nociceptive sensory afferent cell; (ii) a non-cytotoxic protease or a fragment thereof, wherein the protease or protease fragment is capable of cleaving a protein of the exocytic fusion to apparatus of the nociceptive sensory afferent cell; and (iii) a Translocation Domain, wherein the Translocation Domain translocates the protease or protease fragment from within the endosome, across the endosomal membrane, and into the cytosol of the nociceptive sensory afferent cell wherein the Targeting Moiety is selected from the group consisting of BAM, β-endorphin, bradykinin, substance P, dynorphin and/or nociceptin.

The invention provides a cornea metaphase preservation solution, and preparing and using methods thereof. The cornea metaphase preservation solution is a cell culture minimum essential medium (MDM) with chondroitin sulfate, low molecular dextran, L-glutamine, dexamethasone, tobramycin, 2-hydroxyethyl and Y-27632 added. The preservation solution not only can keep activity and normal morphology of cornea endothelial cells, but also can enhance viability of corneal limbus epithelial cells and improve clone ability of corneal limbus stem cells. And especially, a medium to long term preservation effect is obvious, phenomena of deformation, conjugation and the like of endothelial cells of a control group cornea do not appear in long term preservation, endothelial morphology of the control group cornea is consistent with endothelial morphology of a cornea preserved for 4 days, and the endothelial cells of the control group cornea are still regular and few in cell conjugation phenomena. The preservation solution can effectively prevent cell apoptosis phenomena during the process of preserving isolated cornea materials, increases activity and clone forming ability of the corneal limbus stem cells, and enables the cornea to maintain a transparent feature in a long preservation time.

The invention discloses an antibody for resisting human CD79a extracellular terminal protein, a coding gene and application. The antibody is characterized in that a human B cell lymphoma Raji cell line is used as an immunogen for immunizing mice; splenocyte is obtained and then is fused with a mouse myeloma cell to obtain a hybridoma cell; a monoclonal antibody for specifically aiming at the human CD79a extracellular terminal protein is obtained via screening; an amino acid sequence of the monoclonal antibody is obtained by sequence analysis; variable region sequence with a heavy chain and a light chain and CDR (Complementarity-Determining Region) sequences with light chains and heavy chains are obtained via analyzing; an chimeric antibody expressed via cloning can be used for effectively and specifically recognizing the human CD79a extracellular terminal protein; in addition, when the antibody acts on human B lymphocyte, the internalization rate is high; the antibody has a good prospect for preparing a targeted drug of targeted B lymphocyte and can be used for treating diseases associated with the B lymphocyte.

The invention relates to a monoclonal antibody of ractopamine and a preparation method and application thereof, which belongs to the field of immunochemical technology. In the invention, the ractopamine and carrier proteins BSA, HSA and OVA are coupled by a mixed anhydride method to synthesize artificial immunogens RAC-BSA and RAC-HSA and coating antigen RAC-OVA; a Balb/c mouse is immunized by the synthesized artificial immunogens RAC-BSA and RAC-HSA; the spleen cell of the immune mouse is fused with the SP2/0 myeloma cell and the two are coated by the coating antigen RAC-OVA; AND an indirect ELISA method and an indirect competition ELISA method are established to screen out a hybridoma cell strain (5D8) capable of stably excreting specific antibody. The Balb/c mouse is immunized by the obtained cell strain to prepare ascites which is purified by an octanoic acid-ammonium sulfate method and an ion exchange method, and the titer of the purified antibody is more than 5.12*10<5>. The monoclonal antibody has strong specificity, is used for preparing a ractopamine residue detection kit and colloidal gold test paper strips and can sensitively and quickly detect the ractopamine residue.

The invention pertains to the field of the biotechnology. The invention relates to a recombinant protein. The recombinant protein includes two dominant antigenic epitopes of humanized heart type fatty acid binding protein, the amino acid sequence of the recombinant protein is converted into corresponding nucleotide sequence by adopting codon preferred by escherichia coli, chemical synthesis is performed on the nucleotide sequence and recombinant expression vector is constructed, so that protein expression level of the recombinant protein in the escherichia coli is increased. The invention also relates to the preparation of monoclonal antibody of the recombinant protein. Immunization, cell fusion and several rounds of screening are carried out to obtain hybridoma cell strain, the monoclonal antibody is purified and labeled with horse radish peroxidase (HRP), the best matching combination of the monoclonal antibody is determined by ELISA orthogonal experiment, and an early diagnosis application of myocardial infarction is achieved.