2.Comparative study of size and charge heterogeneities of anti-TNF-αantibodies by high performance liquid chromatography
Wei GUO ; Wenbo WANG ; Chuanfei YU ; Feng ZHANG ; Lan WANG ; Chunyu LIU ; Meng LI ; Kai GAO
Chinese Journal of Microbiology and Immunology 2014;(9):723-726
Objective To analyze the differences of size and charge heterogeneities between origi-nal humanized anti-TNF-αantibody and four similar biotherapeutic products ( SBP ) .Methods The size exclusion chromatography ( SEC-HPLC ) and weak cation exchange chromatography ( WCX-HPLC ) were used to analyze the size and charge heterogeneities , respectively.Carboxypeptidase B (CpB) treatment was employed to analyze the source of charge heterogeneity of the antibody products .Results Four SBPs showed the same pattern with the originator in SEC-HPLC, and no significant difference with the percentage of mono-mer was observed .The percentages of the aggregates of SBP-3 and SBP-4 were a little higher than those of the originator .The charge distribution of SBPs was significantly different from the originator ′s, especially in the basic region .The results from the samples treated with CpB indicated that the difference of charge distri -bution in the basic region might be caused by the C-terminal lysine variants .Conclusion Four SBPs showed similar size heterogeneity with the originator , but significant differences with charge heterogeneity were observed among them .The study suggested that more attention should be paid to the charge heterogene -ity analysis of the biosimilar products .
3.Size heterogeneity analysis of monoclonal antibody products
Chuanfei YU ; Wenbo WANG ; Meng LI ; Lan WANG ; Feng ZHANG ; Chunyu LIU ; Kai GAO
Chinese Journal of Microbiology and Immunology 2014;(9):718-722
Objective To compare the capability of capillary electrophoresis-sodium dodecyl sul-fate ( CE-SDS) and size exclusion-high performance liquid chromatography ( SE-HPLC) for analysis of size heterogeneity of monoclonal antibody products .Methods The size heterogeneity of one humanized anti-VEGF monoclonal antibody was analyzed by using non-reduced and reduced CE-SDS, and conventional , de-natured and denatured reduced SE-HPLC.Results The percentage of aggregates detected by non-reduced CE-SDS (0.82%±0.01%) was equal to that by using denatured SE-HPLC (1.05%±0.02%), but it was significantly lower than that by using conventional SE-HPLC analysis (5.08%±0.10%).With regard to fragments analyzed with non-reduced antibodies, its percentage was (7.12±0.04)% measured by non-re-duced CE-SDS analysis that was significantly higher than that by conventional SE -HPLC analysis (0.02%± 0.01%) and denatured SE-HPLC analysis (0.62%±0.01%).Using reduced antibodies , the percentage of fragments was (3.19±0.50)%tested by reduced CE-SDS analysis that was significantly higher than that by using denatured reduced SE-HPLC analysis (0.07%±0.01%).Conclusion Conventional SE-HPLC was more objective than CE-SDS for content analysis of aggregates , as both the covalent and non-covalent forms of aggregates could be detected .Non-reduced CE-SDS could demonstrate the content of clips , while reduced CE-SDS showed the degraded fragments .Therefore, CE-SDS had an advantage over conventional SE-HPLC for content analysis of fragments .The use of the two analytical methods in combination provided solid techni-cal supports for the quality control of size heterogeneity of monoclonal antibodies .
4.Development of a novel reporter gene method for determination of ADCC potency of anti-CD20 monoclonal antibody.
Chunyu LIU ; Lan WANG ; Wei GUO ; Chuanfei YU ; Feng ZHANG ; Wenbo WANG ; Meng LI ; Kai GAO
Acta Pharmaceutica Sinica 2015;50(1):94-8
The biological activity of ADCC by anti-CD20 monoclonal antibody was determined by BioGlo™ Luciferase Assay System using Jurkat/NFAT-luc+FcγRIIIa cell line as effector cell and WIL2-S cell line as target cell. The developed method was verified for specificity, precision and accuracy. Anti-CD20 monoclonal antibody showed a dose-response mode by the developed method, and the determination result complied with the following four-parameter equation: y = (A-D)/[1 + (X/C)(B)] + D. The optimized parameters of the method were determined including the antibodies diluted concentration (18,000 ng·mL(-1)), dilution rate (1:5), the ratio of effector cell and target cell (6:1), and induction time (6 h). The values of eight independent tests have passed a statistical test for curve regression analysis, linear or parallelism, which showed the method possessed good specificity. Four different dilute groups of recovery rates sample were determined for 3 times, and the result showed mean relative potencies of (44.39±3.93)%, (72.74±2.78)%, (128.28±7.01)% and (168.19±2.70)% respectively, with a variation coefficient of less than 10%, and the recoveries of (88.78±7.85)%, (96.99±3.70)%, (102.63±5.61)% and (112.12±1.80)% respectively. A novel reporter gene method for determination of biological activity of ADCC by anti-CD20 monoclonal antibody was successfully developed, which showed strong specificity, good reproducibility and high accuracy, and might be used routinely.
5.Clinicopathologic and immunohistochemical study of primary non-Hodgkin lymphoma of the female genital system
Xue-Feng JIANG ; Kai-Xuan YANG ; Zhi-Lan PENG ; Lian XU ; Qin HUANG ; Qian LI ;
Chinese Journal of Obstetrics and Gynecology 2001;0(04):-
Objective To investigate the clinicopathology and immunophenotype of primary non- Hodgkin lymphoma(NHL)of the female genital system,and to analyze the prognosis of such tumors. Methods Clinicopathologic features of 43 cases of primary NHL of the female genital system were studied retrospectively,with the histological classification based on the Classification of Haematopoietic and Lymphoid Tumors(WHO,2001).Immunochemistry technique,in-situ-hybridization and polymerase chain reaction methods were used to detect the immunophenotype,epstein barrvirus(EB)virus infection status and immunoglobulin heavy chain gene rearrangement,respectively.Results(1)Primary lesions:there were 24 cases of lymphoma originating in the ovary,3 cases in the endometrium,10 cases in the cervix,2 cases in the vagina and 4 cases in the vulva.(2)Staging:12 cases(28%)were in stage Ⅰ,9 cases (21%)in stage Ⅱ,and 22 cases(51%)in stage Ⅲ.(3)Histological classification:37 cases(86%)were diffuse large B cell lymphoma(DLBCL),3 cases were Burkitt lymphoma and the remaining 3 cases were unspecified peripheral T-cell lymphoma according to biopsy,immunophenotype analysis,in-situ- hybridization technique and IgH gene rearrangement detection.(4)Prognosis analysis:increase in the level of lactic acid dehydrogenase,stage Ⅲ,DLBCL and single operation suggest poor prognosis.Conclusions Establishment of the diagnosis of primary NHL of the female genital system is based on biopsy, immunophenotype analysis,in-situ-hybridization technique and IgH gene rearrangement detection,which play important roles in diagnosis and differential diagnosis of the tumor.Combined therapy is the first choice of therapeutic regimens.
6.N terminal sequencing for practical detection of monoclonal antibody.
Wei GUO ; Chuanfei YU ; Meng LI ; Lan WANG ; Feng ZHANG ; Chunyu LIU ; Wenbo WANG ; Kai GAO
Chinese Journal of Biotechnology 2014;30(9):1473-1480
Here we discuss whether N terminal sequencing is appropriate as one of the conventional control methods for monoclonal antibody products. We determined the N terminal sequences of two monoclonal antibody products targeting two antigens separately with both Edman degradation and mass peptide spectrometry. We also identified the characteristic peptide fragments with mass spectrometry. Furthermore, we analyzed their heterogeneity with ion exchange chromatography, capillary zone electrophoresis and Imaged Capillary Isoelectric Focusing. Edman degradation method showed that the N terminal 15 amino acids of heavy and light chains of the two monoclonal antibodies were identical. Peptide mass spectrometry demonstrated that T1 peptide fragments of heavy and light chains of the two antibodies were also the same. But in contrast, peptide mapping and the three analytical methods for heterogeneity analysis could effectively identify and differentiate the two antibodies. The N terminal sequences of two monoclonal antibodies are identical because the number of framework sequences of humanized or human monoclonal antibodies is relatively limited, so whether N terminal sequencing analysis could be regulated as one of the practical control methods should be carefully discussed. Our work also proves that the above analytical methods could combinatorially applied to the identification of monoclonal antibody products, and are more objective compared to N terminal sequencing.
Amino Acid Sequence
;
Antibodies, Monoclonal
;
isolation & purification
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Chromatography, Ion Exchange
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Humans
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Isoelectric Focusing
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Mass Spectrometry
;
Peptide Mapping
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Peptides
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Sequence Analysis, Protein
;
methods
7.Overview of reported transcutaneous electrical acupoint stimulation effects on pain mediators
Kai-Feng DENG ; Ri-Lan CHEN ; Zi-Long LIAO ; Guo-Xiang WANG ; Ying ZHU
Journal of Acupuncture and Tuina Science 2021;19(1):78-82
Literatures on pain intervention with transcutaneous electrical acupoint stimulation (TEAS) were collected by searching the databases both in Chinese and English, and summarized to understand the research progress of TEAS effects on pain mediators in recent years. This will provide a more objective and scientific theoretical basis for clinical practice of TEAS to treat pain syndrome, thus promoting the clinical application of TEAS. Our literature analysis indicated that TEAS effectively regulated the release levels of various pain factors such as prostaglandin, 5-hydroxytryptamine, interleukins, substance P and tumor necrosis factor-α to achieve the analgesic effects by affecting the conduction pathways. TEAS is a safe, non-invasive and effective treatment for pain syndrome. However, further research is necessary due to the lack of rigor of the current clinical trial design.
8.Development of a novel reporter gene method for determination of ADCC potency of anti-CD20 monoclonal antibody.
Chun-yu LIU ; Lan WANG ; Wei GUO ; Chuan-fei YU ; Feng ZHANG ; Wen-bo WANG ; Meng LI ; Kai GAO
Acta Pharmaceutica Sinica 2015;50(1):94-98
The biological activity of ADCC by anti-CD20 monoclonal antibody was determined by BioGlo™ Luciferase Assay System using Jurkat/NFAT-luc+FcγRIIIa cell line as effector cell and WIL2-S cell line as target cell. The developed method was verified for specificity, precision and accuracy. Anti-CD20 monoclonal antibody showed a dose-response mode by the developed method, and the determination result complied with the following four-parameter equation: y = (A-D)/[1 + (X/C)(B)] + D. The optimized parameters of the method were determined including the antibodies diluted concentration (18,000 ng·mL(-1)), dilution rate (1:5), the ratio of effector cell and target cell (6:1), and induction time (6 h). The values of eight independent tests have passed a statistical test for curve regression analysis, linear or parallelism, which showed the method possessed good specificity. Four different dilute groups of recovery rates sample were determined for 3 times, and the result showed mean relative potencies of (44.39±3.93)%, (72.74±2.78)%, (128.28±7.01)% and (168.19±2.70)% respectively, with a variation coefficient of less than 10%, and the recoveries of (88.78±7.85)%, (96.99±3.70)%, (102.63±5.61)% and (112.12±1.80)% respectively. A novel reporter gene method for determination of biological activity of ADCC by anti-CD20 monoclonal antibody was successfully developed, which showed strong specificity, good reproducibility and high accuracy, and might be used routinely.
Antibodies, Monoclonal, Murine-Derived
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pharmacology
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Antibody-Dependent Cell Cytotoxicity
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Antigens, CD20
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immunology
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Genes, Reporter
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Humans
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Reproducibility of Results
;
Rituximab
9.Aging performances for resisting low-temperature of three dental Yttria-stabilized zirconia ceramic core materials.
Rui XIAO ; Bing-Feng CHU ; Lan ZHANG ; Jun-Kai CAO
Chinese Medical Journal 2012;125(11):1999-2003
BACKGROUNDThe low-temperature resistance aging performance of Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) is the key effective factor that influences the long-term success rate of prosthesis. The objective of this study was to test and compare the aging performances for resisting low temperature of Lava Frame, Cercon Smart, and Upcera Yttria-stabilized zirconia core materials, via analyzing the micro and the crystal phases of the materials, and measure the three-point bending strength and the fracture toughness.
METHODSThe three zirconia green bodies were prepared as 60 test samples for three-point bending strength and as 60 test samples for fracture toughness. The test samples for three-point bending strength and fracture toughness were assigned to five groups and were treated respectively for 0, 5, 10, 15, and 20 hours to observe the micro and the crystal phases of the test samples. Then the three-point bending strength and fracture toughness were tested by X-ray diffraction (XRD).
RESULTSThe m phase content of Lava Frame was raised from 7.70% to 13.01%; the m phase content of Cercon Smart was raised from 4.95% to 8.53%; and Lava Frame is raised from 10.84% to 35.18%. The three-point bending strengths of the three zirconia core materials were higher than 1100 MPa and the fracture toughness was higher than 3 MPa·m(1/2). The three-point bending strength and the fracture toughness of Upcra zirconia decreased the most, followed by Lava Frame, and then by Cercon Smart.
CONCLUSIONThe aging resistance sequences of the three zirconia core materials are, from strong to weak, Cercon Smart, Lava Frame, and Upcera.
Ceramics ; chemistry ; Dental Porcelain ; chemistry ; Microscopy, Electron, Scanning ; Temperature ; X-Ray Diffraction ; Yttrium ; chemistry ; Zirconium ; chemistry
10.Determination of drug antibody ratio in an antibody-drug conjugate.
Chuanfei YU ; Meng LI ; Wei GUO ; Lan WANG ; Feng ZHANG ; Chunyu LIU ; Wenbo WANG ; Junzhi WANG ; Kai GAO
Acta Pharmaceutica Sinica 2014;49(3):363-7
This paper reports the determination of the drug antibody ratio in an antibody-drug conjugate with two methods, i.e. LC-MS and UV/VIS, and to provide a reliable method to scientifically evaluate and effectively control the drug antibody ratio. Deglycosylated sample was analyzed with C4 column followed by MS, and the number of conjugated drugs in the antibody was determined by the molecular weight increase due to the addition of different number of drugs to the antibody, and then drug antibody ratio was calculated by weighted average of different number of drugs conjugated to the antibody. Optical density at 252 and 280 nm was measured with UV/VIS, and due to the difference of extinction coefficients between the antibody and the drug, the drug antibody ratio was calculated from linear equation with two unknowns. The drug antibody ratio was 3.21 and 3.25 respectively measured by the two methods, and the results were similar with the two methods. Our study indicated that both methods, LC-MS and UV/VIS, could be applied to the analysis of drug antibody ratio of the antibody drug conjugate.