243 results about "Chinese hamster" patented technology

Methods and compositions for the production of recombinant proteins in a human cell line. The methods and positions are particularly useful for generating stable expression of human recombinant proteins of interest that are modified post-translationally, for example, by glycosylation. Such proteins may have advantageous properties in comparison with their counterparts produced in non-human systems such as Chinese Hamster Ovary cells.

The invention relates to a DNA transmethylase defective CHO (Chinese hamster ovary) cell line and a preparation method and application thereof and belongs to the technical field of gene engineering. DNA Transmethylase Dnmt3a gene of CHO cells is knocked off by means of CRISPR / Cas9 gene editing technique, and screening and identifying are performed to obtain DNA transmethylase Dnmt3a defective CHOcells; the cells are transfected with a eukaryotic expression vector, stably expressed recombinant CHO cell strains are screened, and accordingly a novel CHO cell expression system based on DNA transmethylase deficiency is established. The recombinant gene CHO cell expression system is established via host CHO cell genetic modifications, expression level of recombinant proteins can be significantly increased, the problem of recombinant protein expression instability is solved, and recombinant protein expression stability is improved.

The invention discloses a Chinese hamster ovary (CHO) genetic engineering cell line for performing high-level secretory expression on AcAPc2 and relates to a CHO cell line for performing high-level secretory expression on the AcAPc2. The invention aims to solve the problems that the expression level of an exogenous gene product expressed by using CHO is low at present and the industrialized production cannot be realized. The CHO genetic engineering cell line for performing high-level secretory expression on the AcAPc2 is obtained by the following step of: screening dihydrofolate reductase-deficient CHO cells which are taken as host cells, and amplifying to obtain the cell line for performing stable and high-level expression on the AcAPc2. The CHO cell line can perform high-level expression on the AcAPc2; the expression level can be up to 10mg / L.72h; and the CHO cell line can be industrially produced. The cell line is used for resisting blood coagulation and treating tumor, septicaemiaand the like.

The invention relates to the technical field of medicines for treating diabetes, in particular to a fusion protein for treating diabetes and a preparation method for the fusion protein. The fusion protein is recombined by 2 to 8 Exendin-4-Linkers and a human IgGFc mutant; Linker is a flexible peptide fragment; and the human IgGFc mutant is an IgG1Fc, IgG2Fc or IgG4Fc mutant. The invention also discloses the preparation method for the fusion protein. The recombined fusion protein obtained by the steps of performing high-level expression in Chinese hamster ovary (CHO) cells, affiliating, and performing ion exchange and molecular sieve chromatography has the bioactivities of stimulating the secretion of insulin and inhibiting glucagon generated after dinner from being released which are possessed by Exendin-4, also has the characteristics of prolonging the half-life period of the Exendin-4 in serum, is used for treating type I and type II diabetes, can effectively reduce the psychological and physiological burden of patients, is safe in use and high in practicability, and can be massively produced and sold.

With the goal of creating a combination vaccine against Shigella and other diarrheal pathogens we have constructed a prototype vaccine strain of Shigella flexneri 2a (SC608) that can serve as a vector for the expression and delivery of heterologous antigens to the mucosal immune system. SC608 is an asd derivative of SC602, a well-characterized vaccine strain, which has recently undergone several phase 1 and 2 trials for safety and immunogenicity. Using non-antibiotic asd-based plasmids, we have created novel constructs for the expression of antigens from enterotoxigenic E. coli (ETEC), including CFA / I (CfaB and CfaE) and the B-subunit from heat-labile enterotoxin (LTB) in Shigella vaccine strain SC608. Heterologous protein expression levels and cellular localization are critical to immune recognition and have been verified by immunoblot analysis. Following intranasal immunization (SC608(CFAI) and SC608(CFAI / LTB) of guinea pigs, serum IgG and IgA immune responses to both the Shigella LPS and ETEC antigens can be detected by ELISA. In addition, ELISPOT analysis for ASCs from cervical lymph nodes and spleen showed similar responses. All vaccine strains conferred high levels of protection against challenge with wild-type S. flexneri 2a using the Sereny test. Furthermore, serum from guinea pigs immunized with SC608 expressing CfaB and LTB contained antibodies capable of neutralizing the cytological affects of heat-labile toxin (HLT) on Chinese Hamster Ovary (CHO) cells. These initial experiments demonstrate the validity of a multivalent invasive Shigella strain that can serve as a vector for the delivery of pathogen-derived antigens.

The invention relates to a culture medium and the usage thereof, in particular to the Chinese hamster ovary cell enlarging culture medium and the usage thereof. The invention belongs to the biological product field. The Chinese hamster ovary cell enlarging non-protein culture medium of the invention, wherein comprises minimal medium, and also comprises microelement, Transferrin and Insulin subsistent. A serum-containing routine culture medium can be directly replaced with the serum free culture medium of the Chinese hamster ovary cells, and the Chinese hamster ovary cells are not required to adapt process.

Methods and compositions for the production of recombinant proteins in a human cell line. The methods and compositions are particularly useful for generating stable expression of human recombinant proteins of interest that are modified post-translationally, for example, by glycosylation. Such proteins may have advantageous properties in comparison with their counterparts produced in non-human systems such as Chinese hamster ovary cells.

The invention relates to the field of cell culture, and discloses a CHO (Chinese hamster ovary) cell culture technology capable of reducing content of acidic variants. According to the invention, different basal culture media and concentrated culture media are added in the culture process of the CHO cell technology to increase the expression quantity of recombinant protein and reduce the acid peak level and further increase the quality, so that the technology is applicable to mass production and commercial application of antibody medicines and has better economic benefit.

A Chinese hamster ovary genetic engineering cell line capable of efficiently expressing Ancylostoma caninumanticoagulant peptide 5 (AcAP5) in secretion mode relates to a Chinese hamster ovary (CHO) cell line capable of efficiently expressing the AcAP5 in secretion mode. The cell line resolves the problem that at present, expression amount is low by using CHO to express exogenous gene products, and requirements of industrial production cannot be met. The Chinese hamster ovary genetic engineering cell line for the efficient secretion expression AcAP5 utilizes dihydrofolic acid reductase defect type Chinese hamster ovary cells as host cells, and the cell line capable of stably and efficiently expressing AcAP5 is obtained after the host cells are screened and amplified. The CHO cell line can efficiently express the AcAP5, can be produced in industrialization mode and is used for resisting blood coagulation and thrombus. Furthermore, expression amount can reach to 12 mg / L / 72h.

The invention discloses a preparation method for a replication and transcription activator (Rta) protein and the application of the Rta protein to a nasopharynx cancer detection reagent and relates to a medical diagnosis reagent. The preparation method disclosed by the invention comprises the following steps of: 1, constructing a recombinant expression vector by taking a BRLF1 full-length gene as an exogenous gene; 2, transfecting: transfecting the recombinant expression vector into an eukaryotic expression system to obtain a positive transfected cell; and 3, expressing and purifying: culturing the positive transfected cell so as to enable the positive transfected cell to express an interest protein, and separating and purifying the interest protein, wherein the eukaryotic expression system refers to a Chinese hamster ovary (CHO) cell. The Rta protein prepared by the method disclosed by the invention is used for detecting nasopharynx cancer; the sensitivity of the Rta protein is 96 percent (288 / 300), and the specificity of the Rta protein is 96.7 percent (290 / 300). The sensitivity and the specificity are superior to those of antigens respectively prepared by a prokaryotic expression system and a pichia expression system, and the sensitivity and the specificity on clinical early diagnosis on the nasopharynx cancer are greatly improved.

The invention discloses a recombinant long-acting human hyaluronidase. The recombinant long-acting human hyaluronidase is a fusion protein PH20-HSA or PH20-IgFc of a human hyaluronidase PH20 extracellular part and a human protein (albumin HSA fragment or immunoglobulin IgG2Fc fragment), and the amino acid sequences of the PH20-HSA and the PH20-IgFc are represented by SEQ ID No. 4 and SEQ ID No. 5 respectively, and have the advantages of high in-vivo safety and long half-life. The invention also discloses an encoding gene, an expression vector, a host cell, a production method and a stable preparation of the recombinant long-acting human hyaluronidase. The achievement of industrial level and the obtaining of purified products with active energy are realized through expressing by using GC-rich high expression system and through producing Chinese hamster cells (CHO). The invention further discloses an application of the recombinant long-acting human hyaluronidase in cooperative dosage and the production of micro-molecular hyaluronic acid.

The invention discloses a gene for coding a recombinant human TNFR-Fc fusion protein and an application of the gene. The gene for coding the recombinant human TNFR-Fc fusion protein as shown in SEQ ID NO.1 is obtained by optimized screening of codons. The gene has high expression index in a CHO (Chinese Hamster Ovary) cell, and the expressed protein has high affinity with TNFR. The gene is transferred into the CHO cell to obtain a cell for expressing the recombinant human TNFR-Fc fusion protein. The CHO cell into which the gene is transferred is fermented by using a disposable reactor, the operation is simple, and the obtained protein quantity is higher in comparison with the conventional fermentation tank; and especially after a supplemented medium is added, the cell growth time can be prolonged, the expression level can be increased, the production cost can be reduced, and a high-purity target protein can be obtained.

The present invention is within the field of industrial protein production. The inventors have designed and constructed a new expression system comprising an expression vector coding for a glutamine synthetase of human or dog origin, and a CHO cell line. More specifically, the invention pertains to a combination of (i) a DNA vector suitable for production of a recombinant protein, wherein said vector comprises a sequence coding for a glutamine synthetase, and (ii) a Chinese Hamster Ovary (CHO) cell line, wherein said GS comprises a sequence at least 94.5% identical to the sequence of SEQ ID NO: 1 or to the sequence of SEQ ID NO: 2.