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1.
Article in Chinese | WPRIM | ID: wpr-1006202

ABSTRACT

@#Objective To establish a real-time quantitative PCR method using SYBR GreenⅠto detect the copy numbers of light chain(LC)and heavy chain(HC)of exogenous antibody gene in CHO cells,and verify and preliminarily apply this method.Methods With the B2m(β2-microglobulin)expressed stably in CHO cells as the internal reference gene,suitable primers of LC,HC genes and internal reference gene were designed respectively,and the reaction system and program of the real-time quantitative PCR method were determined. The established method was verified for the specificity,linearity,precision and durability,and used to detect the copy numbers of LC and HC genes in the recombinant cell lines of working cell bank(WCB)and cells of different passages.Results The primers of exogenous genes and internal reference gene showed specific binding to the target fragments;The efficiency of primer amplification for the B2m gene,LC gene,and HC gene was 106. 7%,106. 3% and 99. 1%,respectively,and the correlation coefficients of the linear equations were all greater than 0. 99 with a good linear relationship;The relative standard deviations(RSDs)of precision verification were all less than 1%;Few cycles of freeze-thaw in a short period had little effect on the detection results. The copy numbers of LC and HC genes in different generations of recombinant cell lines detected by the established method showed no obvious changes.Conclusion A real-time quantitative PCR method for the determination of the copy number of exogenous genes in CHO cells was successfully established with good specificity,linearity,precision and durability,which provides a reference for detecting the copy number of exogenous genes expressed in other CHO cell lines

2.
Chinese Pharmacological Bulletin ; (12): 390-396, 2024.
Article in Chinese | WPRIM | ID: wpr-1013633

ABSTRACT

Aim To express and purify recombinant hCGH-CTP fusion protein in high-density suspension culture of Chinese hamster ovary cells (CHO-S), and to verify the lipid accumulation effect of rhCGH-CTP on 3T3-L1 mature adipocytes. Methods The recombinant protein expression vector (pcDNA3. 1-rhCGH-CTP) was constructed, achieved by fusing the human glycoprotein hormone beta 5/alpha 2 cDNA with CTP Linker. The expression plasmid was transiently transfected into the suspended CHO-S to express rhCGH-CTP protein and then purified, and the protein biological activity was verified. Intervention with 3T3-L1 mature adipocyte cells for 24 h was performed to detect the changes of intracellular triglyceride (TG) level. Results Western blot results showed that rhCGH-CTP protein was successfully expressed in CHO-S cells, and the yield was up to 715. 4 mg • L~ . The secreted protein was purified by AKTA pure system with higher purity that was up to 90% as identified by SDS-PAGE. In addition, the intracellular cAMP content of mature adipocytes with high expression of TSHR gene significantly increased after intervention with different concentrations of rhCGH-CTP protein by ELISA kit, indicating that rhCGH-CTP protein had biological activity. Oil red 0 staining showed that compared with the control group, the lipid content of mature adipocytes in the intervention groups with different concentrations of rhCGH-CTP protein significantly decreased (P < 0. 05) . Conclusions The rhCGH-CTP protein has been successfully expressed and purified with biological activity, and effectively reduce TG. This research provides an important theoretical basis for further revealing the physiological role of CGH protein and its potential application in clinical practice.

3.
Chinese Journal of Biotechnology ; (12): 149-158, 2023.
Article in Chinese | WPRIM | ID: wpr-970365

ABSTRACT

Chinese hamster ovary (CHO) cells play an irreplaceable role in biopharmaceuticals because the cells can be adapted to grow in suspension cultures and are capable of producing high quality biologics exhibiting human-like post-translational modifications. However, gene expression regulation such as transgene silencing and epigenetic modifications may reduce the recombinant protein production due to the decrease of expression stability of CHO cells. This paper summarized the role of epigenetic modifications in CHO cells, including DNA methylation, histone modification and miRNA, as well as their effects on gene expression regulation.


Subject(s)
Cricetinae , Animals , Humans , Cricetulus , CHO Cells , Epigenesis, Genetic/genetics , DNA Methylation , Gene Expression Regulation , Recombinant Proteins/genetics
4.
Chinese Journal of Biologicals ; (12): 1497-1502, 2023.
Article in Chinese | WPRIM | ID: wpr-1005875

ABSTRACT

@#Objective To develop a method for monoclonal screening of CHO engineered cell lines using Verified In-situ Plate Seeding(VIPS). Methods Cell pool 1 stably transfected with target gene was inoculated by using monoclonal inoculation/imaging equipment(VIPS)in 96-well plates containing culture medium of different combinations(18 combinations,numbered 1~18)and volumes(100 and 200 μL/well). Monoclonal origin tracing pictures were taken,according to which,the monoclonal inoculation rate,clone formation rate and monoclonal proliferation rate were calculated and the image effects of monoclonal origin were evaluated. The applicability of this method was verified by cell pool 2,cell pool 3 and cell pool 4 stably transfected with target gene. Results The optimum monoclonal medium was Medium Ⅱ,and the volume of medium was 100 μL/well. Under the optimum process conditions,the monoclonal inoculation rate of Cell pool 1 was 80%,the clone formation rate was 83%,the proliferation rate was fast,and the monoclonal origin image was clear. While for Cell pool2,Cell pool 3 and Cell pool 4,the average rate of monoclonal inoculation was 78%,the average rate of clone formation was67%,the proliferation rate was slightly different and the image of cell division process was clear under the optimum process conditions. Conclusion In this study,the monoclonal screening method of CHO engineered cell lines developed using VIPS can improve the clone formation rate of CHO engineered cell lines and provide sufficient proof of monoclonal origin.

5.
Chinese Pharmacological Bulletin ; (12): 774-781, 2023.
Article in Chinese | WPRIM | ID: wpr-1013819

ABSTRACT

Aim To express and purify rhα-Gal A with a 6 X His tag via using a serum-free expression system in high-density suspension culture of Chinese hamster ovary cells ( CHO-S) , and to verify the scavenging effect of rhα-Gal A on globular trisaccharide ceramide (Gb3 or GL3) . Methods The construction of recombinant protein expression vector, pcDNA4-GLA, was achieved by fusing the human α-galactosidase cDNA, gla, with 6 X His tag and artificial DNA synthesis. The expression plasmid was transfected into the suspended CHO-S to express rhα-Gal A and then purified. Following this procedure, we determined rhα-Gal A's expression, the enzymatic activity, and the glycosylation of the recombinant enzyme. Co-incubation with cultured cells was performed to examine whether rhα-Gal A could be taken up into the cells and effectively remove Gb3 substrates. Results rhα-Gal A was successfully expressed and purified after transiently transfecting pcDNA4-GLA into the suspended CHO-S, and the yield was up to (100 ±20. 6) mg • L

6.
Chinese Journal of Biologicals ; (12): 1054-1061+1071, 2023.
Article in Chinese | WPRIM | ID: wpr-996594

ABSTRACT

@#ObjectiveTo achieve efficient expression of human serum albumin(HSA)in Chinese hamster ovary(CHO)cells and optimize its culture technology,so as to lay a foundation of the large-scale production of HSA.MethodsThe eukaryotic expression vector of HSA was constructed by gene recombination technology,and then electrotransfected into fully suspended CHO cells. The monoclonal cell lines with stable and high expression of HSA were screened by G418 and limited dilution method. By adding glucose,sodium butyrate and supplementalmedium to the basal medium,the cell culture process was optimized to improve the expression of HSA. Finally,the scale-up culture verification was carried out in a 5 L bioreactor.ResultsThe recombinant expression vector pcDNA3.1-HSA was successfully constructed and expressed in fully suspended CHO cells. After two monoclonal screening,the secondary monoclonal cell lines CHO-rHSA-7H2A9 and CHOrHSA-7H2D12 were obtained with high HSA expression of 29. 37 mg/L and 25. 26 mg/L respectively. The HSA expression level reached about 100. 00 mg/L by optimizing the culture process and wasfinally increased to 166. 16 mg/L in the 5 L bioreactor,which was about 30 times higher than that in the supernatant of the first monoclonal cells.Conclusion The high level expression of HSA in CHO cells was achieved,which laid a foundation of the further large-scale production of HSA in the field of biological products and solving the market supply problems.

7.
Chinese Journal of Biotechnology ; (12): 3887-3898, 2023.
Article in Chinese | WPRIM | ID: wpr-1008001

ABSTRACT

In order to achieve large-scale production of HSV-IgM (HSV1, HSV2) human-mouse chimeric antibody in vitro, the gene sequence of the corresponding hybridoma cell was harvested by RNA ligase-mediated rapid amplification of cDNA ends (RLM-RACE) technique to clone the chimeric antibody into eukaryotic expression vectors, and express the target proteins in CHO-S cells. At the same time, the screening process of stable cell lines was optimized, and the pressure conditions of pool construction stage and monoclonal screening stage were explored. Finally, the target protein was purified by protein L affinity purification method and the biological activity was detected. The recombinant IgM antibodies, HSV1 and HSV2, weighted at 899 kDa and 909 kDa respectively, were prepared. The optimal screening pressure was 20P200M (the first phase of pressure) and 50P1000M (the second phase of pressure). The final titer for the monoclonal expression of HSV1-IgM and HSV2-IgM was 1 620 mg/L and 623 mg/L, respectively. This study may facilitate the development of quality control products of HSV1 and HSV2 IgM series recombinant antibodies as well as efficient expression of IgM subtype antibodies in vitro.


Subject(s)
Cricetinae , Humans , Animals , Mice , Immunoglobulin M/genetics , Antibodies, Viral , CHO Cells , Cricetulus , Hybridomas , Recombinant Fusion Proteins
8.
Chinese Journal of Biotechnology ; (12): 4784-4795, 2023.
Article in Chinese | WPRIM | ID: wpr-1008058

ABSTRACT

The aim of this study was to produce recombinant porcine interferon gamma (rPoIFN-γ) by Chinese hamster ovarian (CHO) cells expression system and to analyze its antiviral activity. Firstly, we constructed the recombinant eukaryotic expression plasmid pcDNA3.1-PoIFN-γ and transfected into suspension cultured CHO cells for secretory expression of rPoIFN-γ. The rPoIFN-γ was purified by affinity chromatography and identified with SDS-PAGE and Western blotting. Subsequently, the cytotoxicity of rPoIFN-γ was analyzed by CCK-8 test, and the antiviral activity of rPoIFN-γ was evaluated using standard procedures in VSV/PK-15 (virus/cell) test system. Finally the anti-Seneca virus A (SVA) of rPoIFN-γ activity and the induction of interferon-stimulated genes (ISGs) and cytokines were also analyzed. The results showed that rPoIFN-γ could successfully expressed in the supernatant of CHO cells. CCK-8 assays indicated that rPoIFN-γ did not show cytotoxicity on IBRS-2 cells. The biological activity of rPoIFN-γ was 5.59×107 U/mg in VSV/PK-15 system. Moreover, rPoIFN-γ could induced the expression of ISGs and cytokines, and significantly inhibited the replication of SVA. In conclusion, the high activity of rPoIFN-γ was successfully prepared by CHO cells expression system, which showed strong antiviral activity on SVA. This study may facilitate the investigation of rPoIFN-γ function and the development of novel genetically engineered antiviral drugs.


Subject(s)
Animals , Cricetinae , Swine , Interferon-gamma/pharmacology , Cricetulus , CHO Cells , Sincalide , Recombinant Proteins/pharmacology , Antiviral Agents/pharmacology
9.
Chinese Journal of Biotechnology ; (12): 4861-4873, 2023.
Article in Chinese | WPRIM | ID: wpr-1008064

ABSTRACT

The aim of this study was to produce Erns protein of bovine viral diarrhea virus (BVDV) by using suspensively cultured CHO cells expression system and to analyze the immunogenicity of the purified Erns protein. In this study, the recombinant eukaryotic expression plasmid pcDNA3.1-BVDV-Erns was constructed based on the gene sequence of BVDV-1 NADL strain. The Erns protein was secreted and expressed in cells supernatant after transfecting the recombinant expression plasmid pcDNA3.1-BVDV-Erns into CHO cells. The expression and purification of the Erns protein was analyzed by SDS-PAGE, the reactivity was determined with anti-His monoclonal antibodies and BVDV positive serum with Western blotting. Immunogenicity analysis of the Erns protein was determined after immunizing New Zealand white rabbits, and the serum antibodies were tested by indirect ELISA (iELISA) and indirect immunofluorescence (IFA). The serum neutralizing titer of the immunized rabbits was determined by virus neutralization test. The concentration of the purified Erns protein was up to 0.886 mg/mL by BCA protein quantification kit. The results showed that the Erns protein could be detected with anti-His monoclonal antibodies and anti-BVDV sera. Serum antibodies could be detected by iELISA on the 7th day post-prime immunization, and the antibody level was maintained at a high titer until the 28th day post-immunization. The antibody titer was 1:128 000. Furthermore, the expression of the Erns protein in BVDV-infected MDBK cells could be detected with immunized rabbits sera by IFA. Moreover, antigen-specific neutralizing antibodies of 2.71 log10 was induced in rabbits. In this study, purified BVDV Erns protein was successfully produced using CHO suspension culture system, and the recombinant protein was proved to have a good immunogenicity, which may facilitate the development of BVD diagnosis method and novel subunit vaccine.


Subject(s)
Rabbits , Animals , Cricetinae , Cricetulus , CHO Cells , Antibodies, Viral , Diarrhea Viruses, Bovine Viral/genetics , Antibodies, Monoclonal/genetics , Diarrhea , Viral Vaccines/genetics
10.
Article in Chinese | WPRIM | ID: wpr-974734

ABSTRACT

@#Objective To optimize the expression of recombinant human growth hormone-Fc(rhGH-Fc)fusion protein in CHO cells in order to obtain better glycosylation ratio and lower content of highmannose.Methods CHO cells expressing rhGH-Fc were cultured in a 7 L bioreactor.The glycosylation modifications of rhGH-Fc were adjusted by improving the composition of feeding media(using three commercial media:Gly-1:EX-CELL Glycosylation Adjust,Gly-2:SHEFF-CHO PLUS PG ACF and Gly-3:EfficientFeed C + AGT Supplement & GlycanTune C + Total Feed),and the glycosylation type and proportion of the target proteins were analyzed by mass spectrometry.Results The G0F(main glycosylation types:G0,G1 and G2;F:fucose)of Gly-1,Gly-2 and Gly-3 were 32.89%,58.66% and 33.28%,the G1F were 31.39%,18.03%and 34.90%,and the G2F were 31.39%,18.03% and 34.90%,respectively.Gly-1 and Gly-3 made the target protein contain less G0F while more G2F;Gly-3 feeding scheme-showed less high mannose modification than the other two schemes.Conclusion Gly-1 medium changed the glycosylation modification from G0F to G1F and G2F,while Gly-2 medium changed that from G2F and G1F to G0F.However,Gly-3 medium changed the glycosylation modification from G0F to G1F and G2F,and the contentof high mannose was less than 5%,which may have a better effect on modifying glycosylation type and proportion of the target protein.

11.
Article in Chinese | WPRIM | ID: wpr-939659

ABSTRACT

OBJECTIVES@#To study the early clinical efficacy of combined therapy of stage 4 neuroblastoma.@*METHODS@#A retrospective analysis was performed on the medical data and follow-up data of 14 children with stage 4 neuroblastoma who were diagnosed in Hong Kong University-Shenzhen Hospital from January 2016 to June 2021.@*RESULTS@#The median age of onset was 3 years and 7.5 months in these 14 children. Among these children, 9 had positive results of bone marrow biopsy, 4 had N-Myc gene amplification, 13 had an increase in neuron-specific enolase, and 7 had an increase in vanilmandelic acid in urine. Based on the results of pathological examination, differentiated type was observed in 6 children, undifferentiated type in one child, mixed type, in one child and poorly differentiated type in 6 children. Of all the children, 10 received chemotherapy with the N7 regimen (including 2 children receiving arsenic trioxide in addition) and 4 received chemotherapy with the Rapid COJEC regimen. Thirteen children underwent surgery, 14 received hematopoietic stem cell transplantation, and 10 received radiotherapy. A total of 8 children received Ch14.18/CHO immunotherapy, among whom 1 child discontinued due to anaphylactic shock during immunotherapy, and the other 7 children completed Ch14.18/CHO treatment without serious adverse events, among whom 1 child was treated with Lu177 Dotatate 3 times after recurrence and is still undergoing chemotherapy at present. The median follow-up time was 45 months for all the 14 children. Four children experienced recurrence within 2 years, and the 2-year overall survival rate was 100%; 4 children experienced recurrence within 3 years, and 7 achieved disease-free survival within 3 years.@*CONCLUSIONS@#Multidisciplinary combined therapy is recommended for children with stage 4 neuroblastoma and can help them achieve better survival and prognosis.


Subject(s)
Child , Child, Preschool , Humans , Infant , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Combined Modality Therapy , Neuroblastoma/drug therapy , Positron-Emission Tomography , Radionuclide Imaging , Retrospective Studies , Treatment Outcome
12.
Kampo Medicine ; : 367-374, 2022.
Article in Japanese | WPRIM | ID: wpr-986403

ABSTRACT

We investigated the history and indications of Toenho, Kinseiho, and Cho-Sanshaku-Shinteiho, which are different formulae with the same name of seishoekkito. According to the description in “Futsugoyakushitsuhokankuketsu” written by Sohaku Asada, Kinseiho exhibits an immediate effect, while Toenho has preventive effects. However, according to the original text, Kinseiho was formulated such that it could be administered regularly in the summer for prophylaxis. Furthermore, Kinseiho is regarded as a simplified formula with the central structure of Toenho. This implies that Kinseiho is composed of selected crude drugs used in Toenho that are responsible for the main effects of Toenho, such as invigorating spleen energy, clearing fever and generating body fluids. Moreover, there is an instruction to arrange Kinseiho to fit each patient’s condition. In this study, it was found that Cho-Sanshaku-Shinteiho described in “Futsugoyakushitsuhokankuketsu” is a modification of Kinseiho prescribed by Katsuki Gyuzan for patients with fever, consistent with the concept of personalized medicine. The medical extract preparation seishoekkito, which is currently widely used, is Kinseiho. We may use it with heat-clearing formula, fluid-regulating formula or some modifications to make the appropriate formulation based on the patient's symptoms.

13.
Chinese Pharmacological Bulletin ; (12): 795-799, 2022.
Article in Chinese | WPRIM | ID: wpr-1014105

ABSTRACT

Aim To construct Flp-In CHO cell line(CYP2A13-CHO)stably expressing cytochrome P450 family 2 subfamily A member 13(CYP2A13)and Flp-In CHO cell line(CYP2A13-POR-CHO)stably co-expressing CYP2A13 and cytochrome P450 oxidoreductase(POR), from which a cell line with better metabolic activity is selected.Method In our previous study, we had constructed a Flp-In CHO cell line(POR-Flp-In CHO)stably expressing POR using lentiviral vector.The recombinant plasmids of pcDNA5/FRT-CYP2A13 were constructed and transfected into Flp-In CHO cells and POR-Flp-In CHO cells through LipofectamineTM 2000.The expression and activity of CYP2A13 were detected by real-time quantitative PCR(qRT-PCR), Western blot and Aflatoxin B1(AFB1)/4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK)cytotoxicity assay and the metabolic activity was compared between CYP2A13-CHO and CYP2A13-POR-CHO.Results Compared with non-transfected cells, the mRNA and protein expression of CYP2A13 in CYP2A13-CHO and CYP2A13-POR-CHO cells both increased significantly.Besides, compared with CYP2A13-POR-CHO, CYP2A13-CHO cells were more sensitive to AFB1 and NNK.Conclusions The Flp-In CHO cell line stably expressing CYP2A13 and with better metabolic activity has been established successfully, which provides a tool for screening of pre-carcinogens that can be metabolically activated by CYP2A13.

14.
Braz. J. Pharm. Sci. (Online) ; 58: e19692, 2022. graf
Article in English | LILACS | ID: biblio-1384014

ABSTRACT

Abstract The development of stable cell lines producing recombinant proteins is very time-consuming and laborious. One of the practical approaches successfully performed is Fluorescence-Activated Cell Sorting (FACS). A mutated chimeric tissue plasminogen activator (mt-PA) was developed by removing the first three domains of t-PA, insertion of GHRP sequence and mutation toward resistance to plasminogen activator inhibitor-1 (PAI-1). In the current study, a new stable CHO-DG44 cell line producing mt-PA was developed by two sequential clonal selections: FACS and clonal-selection by limiting dilution. Furthermore, the expression was more evaluated using two different expression media. Finally, the high-producing clones were selected based on the dot blot and amidolytic activity test. The transfection efficiency of CHO-DG44 cells was 38% as measured by flow cytometry on green fluorescent protein (GFP). After performing FACS on stable cell pools, the expression yield was increased to fifty-fold. In terms of growth profile, CD-DG44 showed higher viability and cell density results than ProCHO5 medium. The expression of mt-PA was significantly higher in CD-DG44 than in ProCHO5, 765 and 280 IU/mL, respectively. Our data indicated that selection of an appropriate expression medium played a critical role in the development of potent producing stable cells by FACS.


Subject(s)
Tissue Plasminogen Activator , Process Optimization , Flow Cytometry/methods , Fluorescence , Cell Count/instrumentation , Clone Cells/classification , Plasminogen Activator Inhibitor 1/adverse effects , Green Fluorescent Proteins
15.
Article in English | WPRIM | ID: wpr-978352

ABSTRACT

@#Introduction: This preliminary study aimed to non-invasively evaluate choline (CHO), creatine (Cr) and intramyocellular lipid (IMCL) metabolites in skeletal muscles at pre- and post-functional electrical stimulation (FES) exercise among incomplete spinal cord injury (SCI) of American Spinal Injury Association Impairment Scale (ASIA-AIS) D patients using proton magnetic resonance spectroscopy or 1 H-MRS. Methods: These metabolites were measured from the vastus lateralis and semitendinosus muscles of three incomplete SCI ASIA-AIS D patients who completed the FES exercise and later underwent 3 Tesla (T) MRI (repetition time/echo time; TR/TE of 3500ms/100ms, field-ofview; FOV of 20cm, slice thickness of 6mm) and 1 H-MRS (TR/TE of 2000ms/31ms, voxel size of 20mm x 20mm x 35mm). Results: Out of those selected metabolites, only CHO value of vastus lateralis showed a statistically significant difference between pre- and post FES exercise 1 H-MRS scanning (p = 0.01). Conclusion: Therefore, this preliminary finding has postulated that the quantification of muscle metabolites using 1 H-MRS imaging could be used as a potential indicator in evaluating the muscle strength for incomplete SCI ASIA-AIS D patients after the completion of FES cycling exercise.

16.
Article in English | WPRIM | ID: wpr-886694

ABSTRACT

@#Finding stable expression sites on the chromosomes of Chinese hamster ovary (CHO) cells is an effective method to solve the problem of unstable expression of CHO cells in long-term culture. Our group used lentiviral transfection to integrate the tracer gene (Zsgreen1) into the chromosome of CHO cells and found multiple potential stable expression sites. This study verified the ability of one of the sites located in the 148052-148157 bp region on chromosome NW_003614241.1 to stably express exogenous proteins.The expression of Zsgreen1 gene was first observed, and CRISPR/Cas9 technology was then used to integrate the enhanced green fluorescent protein (EGFP) gene into this site. Three strains of EGFP gene integrated cells were obtained. After 60 generations of suspension culture, the fluorescence intensity of the cells had no significant changes, which proved that this site can stably express the EGFP gene. The same method was used to construct recombinant CHO cell lines expressing the human serum albumin (HSA) gene, and was verified by Western blot that this site could express and secrete HSA. It shows that the above-mentioned sites can be integrated and can stably express exogenous proteins.

17.
Chinese Pharmacological Bulletin ; (12): 884-888, 2021.
Article in Chinese | WPRIM | ID: wpr-1014452

ABSTRACT

Aim To establish a method for the stable expression of recombinant humanized Anti-her2 monoclonal antibody and to measure its bioactivity. Methods Anti-her2 heavy chain and light chain eukaryotic expression vectors were used to transfect CHO cells, and then scaled-up after screening the stably expressed cell line. Protein A affinity chromatography was utilized to purify the fusion protein. Western blot was used to identify the properties of the product, SDS-PAGE and HPLC were employed to detect its specificity, and CCK8 assay was used to detect its effect on cell viability. Results One cell line with stable expression of recombinant antibody was selected for scale-up. The supernatant was gained for the purification with protein concentration of 135.9 mg · L

18.
Chinese Journal of Biotechnology ; (12): 312-320, 2021.
Article in Chinese | WPRIM | ID: wpr-878564

ABSTRACT

To enhance recombinant protein production by CHO cells, We compared the impact of overexpression of metabolic enzymes, namely pyruvate carboxylase 2 (PYC2), malate dehydrogenase Ⅱ (MDH2), alanine aminotransferase Ⅰ (ALT1), ornithine transcarbamylase (OTC), carbamoyl phosphate synthetase Ⅰ (CPSⅠ), and metabolism related proteins, namely taurine transporter (TAUT) and Vitreoscilla hemoglobin (VHb), on transient expression of anti-hLAG3 by ExpiCHO-S. Overexpression of these 7 proteins could differentially enhance antibody production. OTC, CPSI, MDH2, and PYC2 overexpression could improve antibody titer by 29.2%, 27.6%, 24.1%, and 20.3%, respectively. Specifically, OTC and MDH2 could obviously improve early-stage antibody production rate and the culture period was shortened by 4 days compared with that of the control. In addition, OTC and MDH2 had little impact on the affinity of anti-hLAG3. In most cases, overexpression of these proteins had little impact on the cell growth of ExpiCHO-S. MDH2 and ALT1 overexpression in H293T cells could also improve antibody production. Overall, overexpression of enzymes involved in cellular metabolism is an effective tool to improve antibody production in transient expression system.


Subject(s)
Animals , Cricetinae , CHO Cells , Cricetulus , Enzymes/metabolism , Recombinant Proteins/genetics
19.
Article in Chinese | WPRIM | ID: wpr-872839

ABSTRACT

Objective:To study the effect of Qiwei Baizhusan (QWBZS) on liver insulin phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt) signal pathway of diabetic mice induced by high-fat diet and streptozotocin (STZ). Method:The methods of network pharmacology and animal experiments were used to study the hypoglycemic effect of QWBZS. Active chemical components of the drug and disease targets selected through public databases were used to construct the protein-protein interaction network (PPIN), and gene ontology(GO) and Kyoto Encyclopedia of Genes and Genomics(KEGG) enrichment analysis was performed to identify relevant signal pathways in vivo. In the pharmacological experiment, the diabetic mice model was established through intraperitoneal injection with 80 mg·kg-1·d-1 STZ high-glucose, high-fat diet. The mice were divided into normal group (normal saline), model group (normal saline) and QWBZS group (18.7 g·kg-1·d-1). After 28 days, the hypoglycemic effect of the drug and its effect on serum total cholesterol (T-CHO), fasting insulin (FINS) and serum tumor necrosis factor-α (TNF-α) were determined. Western blot and Real-time fluorescence quantitative PCR (Real-time PCR) were used to detect protein and mRNA expressions of insulin receptor (IR), insulin receptor substrate-1 (IRS-1),phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt) in liver tissues. Result:A total of 36 active components in this drug were identified by network pharmacology. KEGG analysis suggested that QWBZS might play a role in reducing blood glucose by regulating PI3K Akt signal pathway. Compared with the model group, the levels of blood glucose, serum T-Cho and TNF-α of the intervention group were significantly lower (P<0.01), while the FINS of the intervention group was significantly higher (P<0.01). Protein and mRNA expressions of IR,IRS-1,PI3K and Akt in liver tissues of mice in QWBZS treatment group increased markedly (P<0.05,P<0.01). Conclusion:QWBZS could regulate the levels of blood glucose, TNF-α, T-CHO, and FINS in the serum of diabetic mice induced by high-fat diet and STZ. It can improve PI3K/Akt signal pathway of diabetic mice by regulating protein and mRNA expressions of IR,IRS-1,PI3K and Akt/PKB.

20.
Acta Pharmaceutica Sinica ; (12): 2989-2993, 2020.
Article in Chinese | WPRIM | ID: wpr-862279

ABSTRACT

The major challenge in the development of recombinant biologics lies in generating and isolating rare high-producing stable single clone in a short period of time. The selection marker is an essential component of the plasmid vector, it plays an important part in the generation and screening of producing cell lines. Engineering the selection marker to enhance the stringency of selection for high producing cells is one of the most effective approaches to improve the cell line development process. Here, using Chinese hamaster overy (CHO) cells as an example, we introduce the application of selection marker for generation of recombinant biologics producing mammalian cell lines, methods of engineering the selection markers to enhance the selection stringency, and propose considerations on cell substrate stability and selection marker safety, in order to provide references for high-efficiency development of recombinant biologics.

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