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1.
Cancer Sci ; 110(9): 2722-2733, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31461572

RESUMO

Mesothelin (MSLN) shows increased expression in various cancer cells. For clinical application of antibodies as a positron emission tomography (PET) imaging reagent, a human shortened antibody is essential both for avoiding redundant immune responses and for providing rapid imaging. Therefore, we cloned a single-chain fragment of variable regions (scFv) from a human-derived gene sequence. This was achieved through the construction of a naïve phage library derived from human tonsil lymphocytes. Using a column with human recombinant MSLN, we carried out bio-panning of phage-variants by colony formation. We first obtained 120 clones that were subjected to selection in an ELISA using human recombinant MSLN as a solid phase antigen, and 15 phage clones of scFv with a different sequence were selected and investigated by flow cytometry (FCM). Then, six variants were selected and the individual scFv gene was synthesized in the VL and VH domains and expressed in Chinese hamster ovary cells. Mammalian cell-derived human-origin scFv clones were analyzed by FCM again, and one MSLN highly specific scFv clone was established. PET imaging by 89 Zr-labeled scFv was done in mice bearing xenografts with MSLN-expressing cancer cells, and tumor legions were successfully visualized. The scFv variant established in the present study may be potentially useful for cancer diagnosis by PET imaging.


Assuntos
Proteínas Ligadas por GPI/imunologia , Neoplasias/diagnóstico por imagem , Compostos Radiofarmacêuticos/imunologia , Anticorpos de Cadeia Única/imunologia , Animais , Células CHO , Linhagem Celular Tumoral , Clonagem Molecular , Cricetulus , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/isolamento & purificação , Proteínas Ligadas por GPI/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Imagem Molecular/métodos , Neoplasias/patologia , Biblioteca de Peptídeos , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Radioisótopos , Compostos Radiofarmacêuticos/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Anticorpos de Cadeia Única/administração & dosagem , Ensaios Antitumorais Modelo de Xenoenxerto , Zircônio
2.
Adv Exp Med Biol ; 1140: 225-236, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31347050

RESUMO

Selection of high-producing lead and backup cell lines with high-fidelity primary structure is a major goal of cell line development of protein therapeutics. Conventional techniques for sequence variant analysis, such as mass spectrometry (MS) and next-generation sequencing (NGS) have limitations on the sample number and turnaround time, thus often are only applied at the final stages of development, where an undesired lead or backup clone could cause a significant delay in project timeline. Here we presented a high-throughput (HT) peptide mapping workflow which can be applied at early stages of cell line selection for testing of a batch of 30-40 clones within 2-week turnaround while reporting valuable information on sequence variants and posttranslational modifications (PTMs). The successful application of this workflow was demonstrated for two mAb programs. Multiple clones were removed from a total of 33 mAb-1 clones using various criteria: nine clones contained at least one >1% upregulated unknown peptide ions, 11 clones contained at least eight >0.1% upregulated unknowns, and six clones contained upregulated critical PTMs. For mAb-2, light chain (LC) sequence extension of approximately 30 amino acids were detected in 6 out of 36 clones at levels up to 11%. Besides, a Q to H mutation at ~30% was detected in the heavy chain (HC) of a single clone. Q to H mutation has mass change of 9.00 Da and failed to be detected by intact mass analysis. Rapid PTM quantitation also facilitated the selection of clones with desirable quality attributes, such as N-glycan profile. Hence, we demonstrated a risk-reducing strategy where abnormal clones could be detected at earlier stages of cell line selection, which should result in reduced and more predictable timeline of cell line development.


Assuntos
Anticorpos Monoclonais/química , Sequenciamento de Nucleotídeos em Larga Escala , Mapeamento de Peptídeos , Processamento de Proteína Pós-Traducional , Animais , Células CHO , Cricetinae , Cricetulus , Espectrometria de Massas
3.
Chem Commun (Camb) ; 55(61): 8975-8978, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31290492
4.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(6): 557-562, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31292061

RESUMO

Objective To construct a random mutagenesis library of 3E1D7, a chimerical antibody against c-mesenchymal epithelial transition factor (c-Met), using mammalian cell surface display. Methods Antibody genes with randomly mutated complementarity-determining region 3 (CDR3) part were inserted into the mammalian expression plasmid pSZI-CD to construct the random mutagenesis library using double enzyme digestion. Reconstructed plasmids were then cloned into CHO cells by transfection. The expression level of antibodies on the surface of CHO cells was checked by C6 PLUS flow cytometry. Results 3E1D7 random mutagenesis library was successfully constructed with a volume of 5.52×106 in diversity on gene level. Sequence analysis showed that all 20 clones randomly picked from the library coded for 20 different mutated amino acid sequences in open reading frames. After transfection, the expression of full-length antibodies on CHO cell surfaces could be detected by flow cytometry. Conclusion A random mutagenesis library of a certain anti-c-Met antibody has been successfully constructed with an exhibitable diversity of 5.52×106, which would be a useful platform for further screening of therapeutic antibodies.


Assuntos
Biblioteca Gênica , Vetores Genéticos , Mutagênese , Sequência de Aminoácidos , Animais , Anticorpos/química , Cricetinae , Cricetulus , Fases de Leitura Aberta , Plasmídeos/genética , Transfecção
5.
Pharm Res ; 36(9): 137, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31332533

RESUMO

PURPOSE: Pitt Hopkins Syndrome (PTHS) is a rare genetic disorder caused by mutations of a specific gene, transcription factor 4 (TCF4), located on chromosome 18. PTHS results in individuals that have moderate to severe intellectual disability, with most exhibiting psychomotor delay. PTHS also exhibits features of autistic spectrum disorders, which are characterized by the impaired ability to communicate and socialize. PTHS is comorbid with a higher prevalence of epileptic seizures which can be present from birth or which commonly develop in childhood. Attenuated or absent TCF4 expression results in increased translation of peripheral ion channels Kv7.1 and Nav1.8 which triggers an increase in after-hyperpolarization and altered firing properties. METHODS: We now describe a high throughput screen (HTS) of 1280 approved drugs and machine learning models developed from this data. The ion channels were expressed in either CHO (KV7.1) or HEK293 (Nav1.8) cells and the HTS used either 86Rb+ efflux (KV7.1) or a FLIPR assay (Nav1.8). RESULTS: The HTS delivered 55 inhibitors of Kv7.1 (4.2% hit rate) and 93 inhibitors of Nav1.8 (7.2% hit rate) at a screening concentration of 10 µM. These datasets also enabled us to generate and validate Bayesian machine learning models for these ion channels. We also describe a structure activity relationship for several dihydropyridine compounds as inhibitors of Nav1.8. CONCLUSIONS: This work could lead to the potential repurposing of nicardipine or other dihydropyridine calcium channel antagonists as potential treatments for PTHS acting via Nav1.8, as there are currently no approved treatments for this rare disorder.


Assuntos
Di-Hidropiridinas/farmacologia , Reposicionamento de Medicamentos/métodos , Hiperventilação/tratamento farmacológico , Deficiência Intelectual/tratamento farmacológico , Canal de Potássio KCNQ1/antagonistas & inibidores , Canal de Sódio Disparado por Voltagem NAV1.8/metabolismo , Bloqueadores dos Canais de Potássio/farmacologia , Bloqueadores dos Canais de Sódio/farmacologia , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacologia , Animais , Teorema de Bayes , Células CHO , Cricetulus , Di-Hidropiridinas/química , Facies , Células HEK293 , Humanos , Canal de Potássio KCNQ1/metabolismo , Aprendizado de Máquina , Bloqueadores dos Canais de Potássio/química , Bibliotecas de Moléculas Pequenas/química , Bloqueadores dos Canais de Sódio/química , Relação Estrutura-Atividade , Bloqueadores do Canal de Sódio Disparado por Voltagem/química
6.
Nat Commun ; 10(1): 2766, 2019 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-31235692

RESUMO

A major challenge in biology is that genetically identical cells in the same environment can display gene expression stochasticity (noise), which contributes to bet-hedging, drug tolerance, and cell-fate switching. The magnitude and timescales of stochastic fluctuations can depend on the gene regulatory network. Currently, it is unclear how gene expression noise of specific networks impacts the evolution of drug resistance in mammalian cells. Answering this question requires adjusting network noise independently from mean expression. Here, we develop positive and negative feedback-based synthetic gene circuits to decouple noise from the mean for Puromycin resistance gene expression in Chinese Hamster Ovary cells. In low Puromycin concentrations, the high-noise, positive-feedback network delays long-term adaptation, whereas it facilitates adaptation under high Puromycin concentration. Accordingly, the low-noise, negative-feedback circuit can maintain resistance by acquiring mutations while the positive-feedback circuit remains mutation-free and regains drug sensitivity. These findings may have profound implications for chemotherapeutic inefficiency and cancer relapse.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Redes Reguladoras de Genes/genética , Modelos Genéticos , Animais , Antimetabólitos Antineoplásicos/uso terapêutico , Células CHO , Simulação por Computador , Cricetulus , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Retroalimentação Fisiológica , Regulação da Expressão Gênica/genética , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Puromicina/farmacologia , Puromicina/uso terapêutico , Processos Estocásticos
7.
BMC Infect Dis ; 19(1): 482, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31146699

RESUMO

BACKGROUND: To assess the immune persistence conferred by a Chinese hamster ovary (CHO)-derived hepatitis B vaccine (HepB) 17 to 20 years after primary immunization during early life. METHODS: Participants born between 1997 and 1999 who received a full course of primary vaccination with HepB (CHO) and who had no experience with booster vaccination were enrolled. Blood samples were required from each participant for measurement of hepatitis B surface antibody (anti-HBs), surface antigen and core antibody levels. For those who possessed an anti-HBs antibody < 10 mIU/mL, a single dose of HepB was administered, and 30 days later, serum specimens were collected to assess the booster effects. RESULTS: A total of 1352 participants were included in this study. Of these, 1007 (74.5%) participants could retain an anti-HBs antibody ≥10 mIU/mL, with a geometric mean concentration (GMC) of 57.4 mIU/mL. HBsAg was detected in six participants, resulting in a HBsAg carrier rate of 0.4% (6/1352). Of those participants with anti-HBs antibodies < 10 mIU/mL, after a challenge dose, 231 (93.1%) presented an anti-HBs antibody ≥10 mIU/mL, with a GMC of 368.7 mIU/mL. A significant increase in the anti-HBs positive rate (≥ 10 mIU/mL) after challenge was observed in participants with anti-HBs antibodies between 2.5 and 10 mIU/mL and participants boosted with HepB (CHO), rather than those with anti-HBs antibodies < 2.5 mIU/mL and those boosted with HepB (SC). CONCLUSION: Since satisfactory immune protection against HBV infection conferred by primary vaccination administered 17-20 years ago was demonstrated, there is currently no urgent need for booster immunization.


Assuntos
Anticorpos Anti-Hepatite B/sangue , Vacinas contra Hepatite B/administração & dosagem , Hepatite B/prevenção & controle , Imunização Secundária , Prevenção Primária , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/uso terapêutico , Adolescente , Adulto , Animais , Células CHO , Cricetinae , Cricetulus , Feminino , Seguimentos , Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/imunologia , Vacinas contra Hepatite B/imunologia , Humanos , Recém-Nascido , Masculino , Prevenção Primária/métodos , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
8.
Prep Biochem Biotechnol ; 49(8): 822-829, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31156045

RESUMO

Therapeutic monoclonal antibodies (mAbs) have become the dominant products in biopharmaceutical industry. Mammalian cell expression systems including Chinese hamster ovary (CHO) cells are the most commonly used hosts for the production of complex recombinant proteins. However, development of stable, high producing CHO cell lines suffers from the low expression level and instability of the transgene. The increasing efforts in the development of novel therapeutic antibodies and the advent of biosimilars have revealed the necessity for the development of improved platforms for rapid production of products for initial characterization and testing. In line with this premise, vector design and engineering has been applied to improve the expression level and stability of the transgene. This study reports the application of an improved lentiviral vector system containing the human interferon-ß scaffold attachment region (IFN-SAR) for the development of antibody producing stable CHO cells. mAb expressing clones producing 1100 µg/L of IgG1 monoclonal antibody were isolated without extensive screening of a large number of clones. Our results here indicate the positive effects of IFN-SAR on stable mAb expression using lentiviral based expression vectors. We also observed that although IFN-SAR can improve light chain (LC) and heavy chain (HC) gene copy numbers in stable cell pools, mAb expression in single cell clones was not affected by the transgene copy number.


Assuntos
Anticorpos Monoclonais/genética , Clonagem Molecular/métodos , Vetores Genéticos/genética , Lentivirus/genética , Animais , Células CHO , Linhagem Celular , Cricetulus , Dosagem de Genes , Humanos , Proteínas Recombinantes/genética , Transdução Genética
9.
Acta Crystallogr D Struct Biol ; 75(Pt 6): 554-563, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31205018

RESUMO

HER2, a member of the epidermal growth factor receptor (EGFR) family, has been associated with human breast, ovarian and gastric cancers. Anti-HER2 monoclonal antibodies (mAbs) have demonstrated clinical efficacy for HER2-overexpressing breast cancer. A chimeric antibody chA21 that specifically inhibits the growth of HER2-overexpressing cancer cells both in vitro and in vivo has previously been developed. To reduce a potential human anti-mouse immune response, the humanized antibody HuA21 was developed and was further subjected to affinity maturation by phage display on the basis of chA21. Here, the crystal structure of HuA21-scFv in complex with the extracellular domain of HER2 is reported, which demonstrates that HuA21 binds almost the same epitope as chA21 and also provides insight into how substitutions in HuA21 improve the binding affinity compared with chA21, which could facilitate structure-based optimization in the future. Furthermore, the effects of HuA21 variants with constant domains of different lengths were explored and it was noticed that the deletion of constant domain 1 could improve the inhibition efficacy in a cell-proliferation assay, possibly functioning via increased internalization, which might guide the design of other monoclonal antibodies.


Assuntos
Anticorpos Monoclonais Humanizados/química , Complexo Antígeno-Anticorpo/química , Antineoplásicos Imunológicos/química , Neoplasias/terapia , Receptor ErbB-2/antagonistas & inibidores , Animais , Anticorpos Monoclonais Humanizados/genética , Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos Imunológicos/uso terapêutico , Sítios de Ligação de Anticorpos , Células CHO , Linhagem Celular Tumoral , Cricetinae , Cricetulus , Cristalização , Cristalografia por Raios X/métodos , Feminino , Humanos , Domínios Proteicos , Receptor ErbB-2/imunologia
10.
Dokl Biochem Biophys ; 485(1): 101-103, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31201624

RESUMO

In this paper, we present an approach to optimize the heterologous expression of the receptor tyrosine kinase IRR, which further simplifies the purification of the IRR from the medium and increases the final yield. The approach proposed by us can find application in the biotechnological production of other large-scale recombinant proteins produced for medical purposes.


Assuntos
Receptor de Insulina/biossíntese , Animais , Células CHO , Cricetinae , Cricetulus , Humanos , Domínios Proteicos , Receptor de Insulina/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética
11.
Chem Biol Interact ; 309: 108712, 2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31201777

RESUMO

The recent intentional use of nerve agents and pesticides in Europe and Afghanistan highlights the need for an effective countermeasure against organophosphates (OP) toxins. The most developed pretreatment candidate to date is plasma (native) human butyrylcholinesterase (HuBChE), which is limited in availability and because of its 1:1 stoichiometry with OPs, a large dose will present challenges when delivered parenterally both in terms of pharmacokinetics and manageability in the field. A tetrameric recombinant (r) form of human BChE produced in CHO-K1 cells with similar structure, in vivo stability and antidotal efficacy as the native form, has been developed to deliver rHuBChE as an aerosol (aer) to form a pulmonary bioshield capable of neutralizing inhaled OPs in situ and prevent AChE inhibition in the blood and in the brain; the latter associated with the symptoms of OP toxicity. Previous proof-of-concept macaque studies demonstrated that delivery of 9 mg/kg using a microsprayer inserted down the trachea, resulted in protection against an inhaled dose of 15ug/kg of aer-paraoxon (aer-Px) given 72 h later. In the present studies, pulmonary delivery of rHuBChE in macaques was achieved using Aerogen vibrating mesh nebulizers, similar to that used for human self-administration. The promising findings indicate that despite the poor lung deposition observed in macaques using nebulizers (13-20%), protective levels of RBC-AChE were still present in the blood even when exposure aer-Px (55 µg/kg) was delayed for five days. This long term retention of 5 mg/kg rHuBChE deposited in the lung bodes well for the use of an aer-rHuBChE pretreatment in humans where a user-friendly customized nebulizer with increased lung deposition up to 50% will provide even longer protection at a lower dose.


Assuntos
Aerossóis/química , Butirilcolinesterase/química , Paraoxon/química , Animais , Butirilcolinesterase/genética , Butirilcolinesterase/metabolismo , Células CHO , Cricetinae , Cricetulus , Feminino , Humanos , Pulmão/metabolismo , Macaca , Masculino , Nebulizadores e Vaporizadores , Paraoxon/toxicidade , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/sangue , Proteínas Recombinantes/química
12.
Eur J Med Chem ; 178: 108-115, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31176093

RESUMO

As dual regulators, the PTP-1B signaling pathway and α-glucosidase slow glucose release and increase the degree of insulin sensitivity, representing a promising therapeutic target for type 2 diabetes. In this study, we systematically examined the in vivo and in vitro anti-diabetic activities of natural flavonoids 1-6 from Chrysanthemum morifolium. Flavonoids 1-6 increased glucose consumption-promoting activity and the phosphorylation of GSK-3ß and Akt, and decreased PTP-1B protein level along with slightly inhibitory activity of the PTP-1B enzyme. Moreover, flavonoids 1-2 treatment induced insulin secretion in INS-1 cells. Besides, in vivo study revealed that flavonoids 2 and 5 demonstrated potent anti-hyperglycemic and anti-hyperlipidemic activity, and improved maltose and glucose tolerance. Although flavonoid 2 exhibited lower inhibitory activity against α-glucosidase in vitro, it could deglycosylated in vivo to diosmetin to function as an α-glucosidase inhibitor. Taken together, these results led to the identification of the natural flavonoids 1-6 from C. morifolium as dual regulators of α-glucosidase and the PTP-1B signaling pathway, suggesting their potential application as new oral anti-diabetic drugs or functional food ingredients.


Assuntos
Chrysanthemum/química , Diabetes Mellitus Experimental/tratamento farmacológico , Flavonoides/uso terapêutico , Inibidores de Glicosídeo Hidrolases/uso terapêutico , Hipoglicemiantes/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Colesterol/sangue , Cricetulus , Diabetes Mellitus Experimental/induzido quimicamente , Flavonoides/isolamento & purificação , Glucose/metabolismo , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Hipoglicemiantes/isolamento & purificação , Masculino , Camundongos , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Ratos , Estreptozocina , Triglicerídeos/sangue
13.
Eur J Med Chem ; 178: 243-258, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31185414

RESUMO

To address the multifactorial nature of Alzheimer's Disease (AD), a multi-target-directed ligand approach was herein developed. As a follow-up of our previous studies, a small library of newly designed 2-arylbenzofuran derivatives was evaluated towards cholinesterases and cannabinoid receptors. The two most promising compounds, 8 and 10, were then assessed for their neuroprotective activity and for their ability to modulate the microglial phenotype. Compound 8 emerged as able to fight AD from several directions: it restored the cholinergic system by inhibiting butyrylcholinesterase, showed neuroprotective activity against Aß1-42 oligomers, was a potent and selective CB2 ligand and had immunomodulatory effects, switching microglia from the pro-inflammatory M1 to the neuroprotective M2 phenotype. Derivative 10 was a potent CB2 inverse agonist with promising immunomodulatory properties and could be considered as a tool for investigating the role of CB2 receptors and for developing potential immunomodulating drugs addressing the endocannabinoid system.


Assuntos
Benzofuranos/farmacologia , Inibidores da Colinesterase/farmacologia , Fatores Imunológicos/farmacologia , Fármacos Neuroprotetores/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/antagonistas & inibidores , Animais , Benzofuranos/síntese química , Benzofuranos/química , Benzofuranos/metabolismo , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Células CHO , Domínio Catalítico , Linhagem Celular Tumoral , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/metabolismo , Cricetulus , Desenho de Drogas , Humanos , Fatores Imunológicos/síntese química , Fatores Imunológicos/química , Fatores Imunológicos/metabolismo , Camundongos , Microglia/efeitos dos fármacos , Simulação de Acoplamento Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/metabolismo , Fragmentos de Peptídeos/antagonistas & inibidores , Ligação Proteica , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo
14.
Sheng Wu Gong Cheng Xue Bao ; 35(6): 1071-1078, 2019 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-31232003

RESUMO

The aim of this study is to investigate the effect of the chimeric intron in different directions on the expression of the nerve growth factor (NGF) in recombinant Chinese hamster ovary (CHO) cells. The chimeric intron that contained the splice sequence of the first intron of the human ß-globin and the human immunoglobulin heavy chain variable region intron was used. NGF gene was cloned into the expression vectors containing the chimeric intron in the forward or reverse direction, followed by transfecting into CHO cells, and screened under G418 to produce the stable transfected CHO cells. Fluorescence quantitative PCR, ELISA, and Western blotting were performed to detect the recombinant NGF gene expression in CHO cells. The results showed that the chimeric introns could significantly enhance the expression of NGF in recombinant CHO cells. Moreover, the enhancing effect on NGF expression level by the intron in the forward direction showed stronger than that of the reverse direction both at mRNA and protein level. In conclusion, the chimeric intron could increase NGF expression in stably transfected CHO cells and the effect is associated with the direction of the intron insertion.


Assuntos
Íntrons , Animais , Animais Geneticamente Modificados , Células CHO , Cricetinae , Cricetulus , Expressão Gênica , Humanos , Transfecção
15.
Soft Matter ; 15(20): 4178-4186, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31062781

RESUMO

A novel cellular automaton (CA) for simulating biological membrane rupture is proposed. Constructed via simple rules governing deformation, tension, and fracture, the CA incorporates ideas from standard percolation models and bond-based fracture methods. The model is demonstrated by comparing simulations with experimental results of a double bilayer lipid membrane expanding on a solid substrate. Results indicate that the CA can capture non-trivial rupture morphologies such as floral patterns and the saltatory dynamics of fractal avalanches observed in experiments. Moreover, the CA provides insight into the poorly understood role of inter-layer adhesion, supporting the hypothesis that the density of adhesion sites governs rupture morphology.


Assuntos
Membrana Celular/metabolismo , Bicamadas Lipídicas/química , Animais , Células CHO , Cálcio/química , Cátions Bivalentes , Simulação por Computador , Cricetulus , Feminino , Fractais , Interações Hidrofóbicas e Hidrofílicas , Modelos Biológicos , Termodinâmica
16.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1118-1119: 194-202, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31059926

RESUMO

A rapid and sensitive liquid chromatography-mass spectrometry assay was developed and used to quantify emetic cereulide peptide exotoxin, which can be related to possible Bacillus cereus contamination in monoclonal antibody (mAb) bioprocess feeds. The assay limit of detection was 0.05 ng/mL (~1 fmol injected) and limit of quantification 0.16 ng/mL (~3 fmol injected) over a standard curve with >3 orders of magnitude linear dynamic range. The assay allowed quantification of toxin removal in an established two-step mAb purification process consisting of Protein A affinity chromatography followed by multi-modal anion exchange chromatography. Toxin content was ascertained in process stream sample fractions as well as on the Protein A affinity column. An optimized analytical method allowed separation of cereulide toxin from other mAb cell culture components within 6 min. Spiking experiments showed that samples should be collected in high (80% v/v) content acetonitrile to reduce nonspecific losses of the cereulide. The majority of mAb purification process-associated cereulide was detected in the Protein A flow through fraction, whereas only residual amounts were found in wash, strip, and elution fractions. Column cleaning-in-place (CIP) procedures were evaluated to prevent carryover between affinity capture cycles. No carryover was detected between cycles, however trace amounts of cereulide were extracted from the Protein A resin. Increasing the CIP NaOH concentration from 0.1 M to 0.5 M, and contact time from 15 min to 1 h, improved removal of residual cereulide from the resin. Applicability of CIP clearance of cereulide during Protein A chromatography was confirmed with three different mAb feeds. Post Protein A polishing, via target flow through on a multi-modal anion exchange chromatography column, resulted in a product pool with no detectable cereulide. Approximately 5 logs of reduction in cereulide concentration was obtained over the two-step chromatography process. Cereulide contamination is well known and of concern in food processing, however this research may be the first LC-MS quantification of cereulide contamination, and its clearance, in biopharmaceutical mAb processing. The analytical method may also be used to rapidly screen for cereulide contamination in upstream cell culture process streams, prior to downstream product purification. This will allow appropriate measures to be taken to reduce toxin exposure to downstream bioprocess raw materials, consumables and equipment.


Assuntos
Anticorpos Monoclonais/química , Toxinas Bacterianas/isolamento & purificação , Cromatografia de Afinidade/métodos , Depsipeptídeos/isolamento & purificação , Proteína Estafilocócica A/metabolismo , Animais , Bacillus cereus , Células CHO , Cricetinae , Cricetulus , Depsipeptídeos/metabolismo , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
17.
Nat Commun ; 10(1): 1785, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-31040271

RESUMO

Lysosomal replacement enzymes are essential therapeutic options for rare congenital lysosomal enzyme deficiencies, but enzymes in clinical use are only partially effective due to short circulatory half-life and inefficient biodistribution. Replacement enzymes are primarily taken up by cell surface glycan receptors, and glycan structures influence uptake, biodistribution, and circulation time. It has not been possible to design and systematically study effects of different glycan features. Here we present a comprehensive gene engineering screen in Chinese hamster ovary cells that enables production of lysosomal enzymes with N-glycans custom designed to affect key glycan features guiding cellular uptake and circulation. We demonstrate distinct circulation time and organ distribution of selected glycoforms of α-galactosidase A in a Fabry disease mouse model, and find that an α2-3 sialylated glycoform designed to eliminate uptake by the mannose 6-phosphate and mannose receptors exhibits improved circulation time and targeting to hard-to-reach organs such as heart. The developed design matrix and engineered CHO cell lines enables systematic studies towards improving enzyme replacement therapeutics.


Assuntos
Lisossomos/enzimologia , Animais , Células CHO , Cricetinae , Cricetulus , Modelos Animais de Doenças , Doença de Fabry/tratamento farmacológico , Doença de Fabry/enzimologia , Doença de Fabry/metabolismo , Glicosilação , Masculino , Camundongos , Camundongos Knockout , Proteínas Recombinantes/uso terapêutico , alfa-Galactosidase/uso terapêutico
18.
Prep Biochem Biotechnol ; 49(8): 735-743, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31135267

RESUMO

Type I interferons (IFNs) are homologous cytokines that bind to a cell surface receptor and establish signaling pathways that motivate immune responses. The purpose of the current study is to assess the activity of a novel-engineered IFN-α2b. The crystallographic structure of IFN-α2b and its receptors was acquired from Protein Data Bank. Various amino acid substitutions were designed based on structural properties and other biological characteristics of residues to find the most effective amino acid on IFN affinity to advanced activities. The IFN-α2b mutants and receptors have been modeled and the interactions between two proteins have been studied as in silico by protein-protein docking for both mutants and native forms. The proper nucleic acid sequence IFN-α2 (T79Q) has been prepared based on the selected mutant. The modified IFN gene was cloned in pcDNA 3.1(-) and introduced to Chinese Hamster Ovary (CHO) cell line. Antiviral and antiproliferative assays of native and IFN-α2 (T79Q) proteins were performed in vitro. The results showed two-fold increasing in IFN-α2 (T79Q) activity (antiviral and antiproliferative activity) in comparison to native IFN-α2b. This engineered IFN-α2b may have significant novel therapeutic applications and in silico studies can be an influential method for practical research function and structure of these molecules.


Assuntos
Substituição de Aminoácidos , Interferon-alfa/genética , Interferon-alfa/metabolismo , Engenharia de Proteínas , Receptores de Interferon/metabolismo , Animais , Antivirais/química , Antivirais/metabolismo , Antivirais/farmacologia , Células CHO , Proliferação de Células/efeitos dos fármacos , Cricetulus , Células HeLa , Humanos , Interferon-alfa/química , Interferon-alfa/farmacologia , Simulação de Acoplamento Molecular , Conformação Proteica , Engenharia de Proteínas/métodos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia
19.
Nat Commun ; 10(1): 2172, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-31092829

RESUMO

Inducing mitochondrial uncoupling (mUncoupling) is an attractive therapeutic strategy for treating metabolic diseases because it leads to calorie-wasting by reducing the efficiency of oxidative phosphorylation (OXPHOS) in mitochondria. Here we report a safe mUncoupler, OPC-163493, which has unique pharmacokinetic characteristics. OPC-163493 shows a good bioavailability upon oral administration and primarily distributed to specific organs: the liver and kidneys, avoiding systemic toxicities. It exhibits insulin-independent antidiabetic effects in multiple animal models of type I and type II diabetes and antisteatotic effects in fatty liver models. These beneficial effects can be explained by the improvement of glucose metabolism and enhancement of energy expenditure by OPC-163493 in the liver. Moreover, OPC-163493 treatment lowered blood pressure, extended survival, and improved renal function in the rat model of stroke/hypertension, possibly by enhancing NO bioavailability in blood vessels and reducing mitochondrial ROS production. OPC-163493 is a liver-localized/targeted mUncoupler that ameliorates various complications of diabetes.


Assuntos
Hipoglicemiantes/farmacologia , Fígado/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Desacopladores/farmacologia , Administração Oral , Animais , Pressão Sanguínea/efeitos dos fármacos , Células CHO , Cricetulus , Diabetes Mellitus/sangue , Diabetes Mellitus/tratamento farmacológico , Modelos Animais de Doenças , Fígado Gorduroso/tratamento farmacológico , Fígado Gorduroso/etiologia , Fígado Gorduroso/patologia , Feminino , Células Hep G2 , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/etiologia , Hipertensão/mortalidade , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/uso terapêutico , Rim/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Mitocôndrias/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/mortalidade , Análise de Sobrevida , Desacopladores/farmacocinética , Desacopladores/uso terapêutico
20.
Ecotoxicol Environ Saf ; 180: 357-365, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31102843

RESUMO

Organic pollutants attached on road deposited sediments (RDS) during dry days can be washed-off into stormwater runoff during rainfall events, undermining stormwater reuse safety. Previous research studies commonly utilized individual pollutant groups and their quantity to evaluate the hazard effect of pollutants attached to RDS in terms of stormwater reuse. Since many types of organic pollutants are present together rather than individually, conventional approaches might not permit a comprehensive understanding of how appropriately the RDS polluted stormwater can be reused. This study undertook a toxicity test of organic pollutants attached to RDS using Chinese hamster ovary cells (CHO), testing a hypothesis that solely focusing on individual pollutant groups are not adequate to represent hazard effects of resulting stormwater and hence their adequacy for reuse. It is noted that comparative toxicity of RDS is not strongly related to total solids (commonly seen as the key carrier of pollutants) and chemical oxygen demand (COD, representing organic matters). Additionally, the comparison results of spatial distributions of toxicity (in this study) and individual pollutants in previous studies did not show a similar trend. These results imply that toxicity should be also used to indicate how stormwater can be safely reused while solely investigating individual pollutants can not adequately show a comprehensive hazard effect in terms of ensuring stormwater reuse safety. Based on study outcomes, a new assessment approach considering both pollutant and toxicity were proposed. This will assist on effective stormwater reuse and ensuring their reuse safety.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Chuva/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Animais , Análise da Demanda Biológica de Oxigênio , Células CHO , Sobrevivência Celular/efeitos dos fármacos , China , Cricetinae , Cricetulus , Poluentes Químicos da Água/toxicidade
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