AIM: To generate soluble single chain variable fragments (ScFv) of monoclonal antibody MC3 recognizing colorectal and gastric carcinomas. METHODS: mRNA was isolated from the hybridoma cell line producing MC3 and the D...AIM: To generate soluble single chain variable fragments (ScFv) of monoclonal antibody MC3 recognizing colorectal and gastric carcinomas. METHODS: mRNA was isolated from the hybridoma cell line producing MC3 and the DNAs encoding variable domains of heavy and light chains (VH and VL) of the antibody were amplified separately by RT-PCR and assembled into ScFv DNA with a linker DNA. The ScFv DNA was ligated into the phagemid vector pCANTAB5E and the ligated sample was transformed into E.coli TG1.The transformed cells were infected with M13KO7 helper phage to yield recombinant phages. After two rounds of panning with gastric carcinoma cell line AGS highly expressing MC3-binding antigen, the phage clones displaying ScFv fragments of the antibody were selected by ELISA. 4 phage clones showing strong signal in ELISA were used to infect E.coli HB2151 to express soluble ScFvs. The soluble ScFvs were identified by Dot blot and Western blot, and their antigen-binding activity was assayed by ELISA. The VH and VL DNAs of the ScFv DNA derived from phage clone 19 were sequenced. RESULTS: The VH,VL and ScFv DNAs were about 340 bp, 320 bp and 750 bp respectively. After two rounds of panning to the recombinant phages, 18 antigen-positive phage clones were selected from 30 preselected phage clones by ELISA. All the soluble ScFvs derived from the 4 out of the 18 antigen-positive phage clones were about M(r)32000 and concentrated in periplasmatic space under the given culture condition. The soluble ScFvs could bind the antigen, and they shared the same binding site with MC3. The sequences of the VH and VL DNAs of the MC3 ScFv showed that the variable antibody genes belonged to the IgG1 subgroup,kappa-type. CONCLUSION: The soluble ScFv of MC3 is successfully produced, which not only provides a possible novel targeting vehicle for in vivo and in vitro study on associated cancers, but also offers the antibody a stable genetic source.展开更多
E.coli cells expressing recombinant human interferon-γ was disrupted by sonication anddissolved in 7mol·L<sup>-1</sup> guanidine hydrochloride.The extract obtained was then renaturated by 70 folddilu...E.coli cells expressing recombinant human interferon-γ was disrupted by sonication anddissolved in 7mol·L<sup>-1</sup> guanidine hydrochloride.The extract obtained was then renaturated by 70 folddilution with PBS.HulFN γ was purified by affinity chromatography with monoclonal antibody fromthe renaturated crude feed solution.After washing the column with PBS,the adsorbed HulFN γ waseluted with PBS containing 0.5mol·L<sup>-1</sup> NaCl.The column was regenerated with 2mol·L<sup>-1</sup> GuHClfor reuse.After one step of affinity purification the purity of interferon-γ was over 95%.and thespecific activity of the HulFN-γ reached 1.2×10<sup>7</sup> IU·mg<sup>-1</sup> protein.92.8% of recovery was obtainedin the elution step.Total recovery of HulFN γ activity in the affinity chromatography was 78%.展开更多
Objective To produce specific monoclonal antibody （mAb） against recombinant human erythropoietin （rHuEPO） for development of highly efficient methods for erythropoietin detection in biological fluids. Methods rHuE...Objective To produce specific monoclonal antibody （mAb） against recombinant human erythropoietin （rHuEPO） for development of highly efficient methods for erythropoietin detection in biological fluids. Methods rHuEPO was covalently coupled with bovine serum albumin （BSA） and the conjugate was used to immunize mice to produce specific mAb against rHuEPO based on hybridoma technology. The obtained F3-mAb was characterized by enzyme-linked irmnunosorbent assay （ELISA）, SDS-PAGE and Western blot. Results The isotype of F3-mAb was found to be IgM with an affinity constant of 2.1x10s L/mol. The competitive ELISA using the obtained IgM showed a broader linear range and lower detection limit compared with previous work. Conclusions The modification of rHuEPO was proved to be successful in generating required specific mAb with high avidity to rHuEPO.展开更多
A new way for the synthesis of human interferon—α_A monoclonal antibody (IFN-α_A-McAb) bound to silica gel packing material in high-performance affinity chromatography (HPAFC) has been developed. The high coupling ...A new way for the synthesis of human interferon—α_A monoclonal antibody (IFN-α_A-McAb) bound to silica gel packing material in high-performance affinity chromatography (HPAFC) has been developed. The high coupling efficiency and specific activity of IFN—α_A-McAb can be obtained by activated diol-silica gel with activating agent. After purification using this packing material in HPAFC, the specific activity of recombinant human interferon-α_A (rIFN-α_A) rose up to 1.03×10~7IU/mg protein and the purification efficiency is appoximately 100 times.展开更多
P65 protein, the major immunodominant protein of Mycoplasma hyopneu-moniae （Mhp） exhibiting no cross-reaction with other mycoplasmas, is general y used as a target protein for Mhp detection. In this study, BALB/c mi...P65 protein, the major immunodominant protein of Mycoplasma hyopneu-moniae （Mhp） exhibiting no cross-reaction with other mycoplasmas, is general y used as a target protein for Mhp detection. In this study, BALB/c mice were immunized with prokaryotical y expressed P65 recombinant protein to prepare monoclonal anti-body. After screening with Mhp whole-cel protein and P65 protein, a specific hy-bridoma cel line, 3G12, was obtained by ELISA. Identification results indicated that the antibody secreted by 3G12 hybridoma cel s could react with P65 protein and Mhp whole-cel protein. According to indirect ELISA assay, 3G12 cel culture super-natant possessed a titer of 1∶12 800 against P65 protein and 1∶3 200 against Mhp whole-cel protein; 3G12 ascites possessed a titer of above 1∶4 000 000 against P65 protein and above 1∶20 000 against Mhp 168 whole-cel protein. After long-term in vitro culture and continuous freezing-thawing, 3G12 cel line could stably secrete antibodies. A monoclonal antibody against P65 protein and Mhp whole-cel protein was successful y obtained in the present study, which provided basis for further in-vestigating the pathogenic mechanism of Mhp and establishing diagnostic methods of Mycoplasmal pneumonia of swine （MPS）.展开更多
In this study, a panel of monoclonal antibodies （mAbs） against Porcine reproductive and respiratory syndrome virus（PRRSV）, named as 8C9 and4B4, were produced by fusing SP2/0 myeloma cells and spleen cells of BALB/...In this study, a panel of monoclonal antibodies （mAbs） against Porcine reproductive and respiratory syndrome virus（PRRSV）, named as 8C9 and4B4, were produced by fusing SP2/0 myeloma cells and spleen cells of BALB/c mice immunized with the PRRSV （TCID50=5.5）, screened by the indirect ELISA and subjected to several limiting dilutions, mAbs were then identified by biological characterization. Among the two fusion cell strains, 8C9 belonged to the IgG1 subclass and 4B4 belonged to the IgG2a subclass. The titers in cell culture supematant and abdomen liquor reached to 1：104and 1：105, respectively. The specificity test indicated that the two cells had specific reactions for the PRRSV and GP5 protein respectively, and no reaction with Classical swine fever virus （CSFV） or Swine vesicular disease virus （SVDV）. The molecular weights of the heavy chain and light chain were about 45.0 kDa and 25.0 kDa, respectively. In neutralization activity tests, the results showed that the prepared mAb 4B4 can protect 50% of cells with no CPE in dilution up to 1：512, but mAB 8C9 has no neutralization activities to PRRSV.展开更多
The gene encoding the VP28 envelope protein of White spot syndrome virus (WSSV) was cloned into expression vector pET-30a and transformed into the Escherichia coli strain BL21.After induction,the recombinant VP28 (rVP...The gene encoding the VP28 envelope protein of White spot syndrome virus (WSSV) was cloned into expression vector pET-30a and transformed into the Escherichia coli strain BL21.After induction,the recombinant VP28 (rVP28) protein was purified and then used to immunize Balb/c mice for monoclonal antibody (MAb) production.It was observed by immuno-electron microscopy the MAbs specific to rVP28 could recognize native VP28 target epitopes of WSSV and dot-blot analysis was used to detect natural WSSV infection.Competitive PCR showed that the viral level was approximately 104 copies/mg tissue in the dilution of gill homogenate of WSSV-infected crayfish at the detection limit of dot-blot assay.Our results suggest that dot-blot analysis with anti-rVP28 MAb could rapidly and sensitively detect WSSV at the early stages of WSSV infection.展开更多
Fifteen hybridoma cell lines producing monoclonal antiboclies (McAb) against recombinant human tu-mor necrosis factor a (rhTNFa) have been established by fusing SP 2/0 cells with spleen cells from aBALB/c mouse immuni...Fifteen hybridoma cell lines producing monoclonal antiboclies (McAb) against recombinant human tu-mor necrosis factor a (rhTNFa) have been established by fusing SP 2/0 cells with spleen cells from aBALB/c mouse immunized with rhTNFa. Following J M Davis’s Works, semi-solid medium was usedfor initial cloning. Five of them were studied further. Their main chromosome- numbers range were 96 to105, all of them were IgG1 subclass. The affinities of these McAbs were estimated to be 1. 25 ×108 mol/L, 1. 12×108 mol/L, 2. 34×108 mol/L, 8. 55 × 107 mol/L, 1. 04×108 mol/L, respectively.Two groups of mice challenging with E Coli (107 organisms), one group treated with 2mg/kg anti-TNF monoclonal antibody, the other did not. There was a higher survival rate in treated group, the serumTNF level was significantly lower too, and the untreated mice had severe pathologic changes in vlscera.展开更多
In order to improve the clinical usefulness of mAb of mouse origin in targeting diagnosis and therapy for human brain glioma, it is necessary to humanize it and reduce its molecular size. By means of RT-PCR technique,...In order to improve the clinical usefulness of mAb of mouse origin in targeting diagnosis and therapy for human brain glioma, it is necessary to humanize it and reduce its molecular size. By means of RT-PCR technique, a 348 bp heavy chain variable domain (VH),and a 318 bp light chain variable domain (VL) cDNA fragments were cloned from mouse hybridoma cell line SZ39 secreting mAb against human brain glioma. By recombinant DNA technique, the two cDNA 'fragments were linked to human IgGI heavy chain CHI and light chain K constant regions, respectively, to form a mouse/human chimeric gene which was then inserted into an expression vector pHENI-SZ39 Fab/Hu. In addition,the two cDNA fyagments were linked directly with a universal link6r and inserted into an expression vector pHENI-SZ39ScFv. The two expression vectors were separately introduced into non-suppressor E.coli HB2151to secrete chimeric antibodies and single-chain antibodies,respectively. On ELISA and Western blot assays, the two genetically engineered antibodies were bound specifically to the same 180 kD cell surface membrane antigen on human brain glioma cell line SHG44 as did the parental mAb SZ39.展开更多
目的建立并验证一种检测单克隆抗体药物中重组人透明质酸酶(recombinant human hyaluronidase,rHuPH20)活性的方法。方法利用浊度法建立单克隆抗体药物中rHuPH20活性的检测方法,并对该方法的专属性、线性、中间精密度、准确度、重复性...目的建立并验证一种检测单克隆抗体药物中重组人透明质酸酶(recombinant human hyaluronidase,rHuPH20)活性的方法。方法利用浊度法建立单克隆抗体药物中rHuPH20活性的检测方法,并对该方法的专属性、线性、中间精密度、准确度、重复性进行验证。结果该方法专属性良好,空白和不添加rHuPH20的单克隆抗体药物的rHuPH20活性均<4 U/ml。在3.5~26.7 U/ml范围内,供试品rHuPH20理论活性和实测活性线性相关,决定系数R^(2)>0.97;中间精密度试验结果的变异系数(coefficient of variation,CV)均<15%;各rHuPH20活性的平均值回收率在95%~105%之间,符合线性、中间精密度和准确度的验证要求。6次独立测定3批供试品rHuPH20活性的变异系数分别为6.56%,2.96%和4.10%,符合重复性的可接受标准(≤10%)。结论该方法各项指标均符合要求,可对单克隆抗体药物中rHuPH20活性进行质量控制。展开更多
文摘AIM: To generate soluble single chain variable fragments (ScFv) of monoclonal antibody MC3 recognizing colorectal and gastric carcinomas. METHODS: mRNA was isolated from the hybridoma cell line producing MC3 and the DNAs encoding variable domains of heavy and light chains (VH and VL) of the antibody were amplified separately by RT-PCR and assembled into ScFv DNA with a linker DNA. The ScFv DNA was ligated into the phagemid vector pCANTAB5E and the ligated sample was transformed into E.coli TG1.The transformed cells were infected with M13KO7 helper phage to yield recombinant phages. After two rounds of panning with gastric carcinoma cell line AGS highly expressing MC3-binding antigen, the phage clones displaying ScFv fragments of the antibody were selected by ELISA. 4 phage clones showing strong signal in ELISA were used to infect E.coli HB2151 to express soluble ScFvs. The soluble ScFvs were identified by Dot blot and Western blot, and their antigen-binding activity was assayed by ELISA. The VH and VL DNAs of the ScFv DNA derived from phage clone 19 were sequenced. RESULTS: The VH,VL and ScFv DNAs were about 340 bp, 320 bp and 750 bp respectively. After two rounds of panning to the recombinant phages, 18 antigen-positive phage clones were selected from 30 preselected phage clones by ELISA. All the soluble ScFvs derived from the 4 out of the 18 antigen-positive phage clones were about M(r)32000 and concentrated in periplasmatic space under the given culture condition. The soluble ScFvs could bind the antigen, and they shared the same binding site with MC3. The sequences of the VH and VL DNAs of the MC3 ScFv showed that the variable antibody genes belonged to the IgG1 subgroup,kappa-type. CONCLUSION: The soluble ScFv of MC3 is successfully produced, which not only provides a possible novel targeting vehicle for in vivo and in vitro study on associated cancers, but also offers the antibody a stable genetic source.
文摘E.coli cells expressing recombinant human interferon-γ was disrupted by sonication anddissolved in 7mol·L<sup>-1</sup> guanidine hydrochloride.The extract obtained was then renaturated by 70 folddilution with PBS.HulFN γ was purified by affinity chromatography with monoclonal antibody fromthe renaturated crude feed solution.After washing the column with PBS,the adsorbed HulFN γ waseluted with PBS containing 0.5mol·L<sup>-1</sup> NaCl.The column was regenerated with 2mol·L<sup>-1</sup> GuHClfor reuse.After one step of affinity purification the purity of interferon-γ was over 95%.and thespecific activity of the HulFN-γ reached 1.2×10<sup>7</sup> IU·mg<sup>-1</sup> protein.92.8% of recovery was obtainedin the elution step.Total recovery of HulFN γ activity in the affinity chromatography was 78%.
基金This work was supported by the National Natural Science Foundation of China (No.20675006).
文摘Objective To produce specific monoclonal antibody （mAb） against recombinant human erythropoietin （rHuEPO） for development of highly efficient methods for erythropoietin detection in biological fluids. Methods rHuEPO was covalently coupled with bovine serum albumin （BSA） and the conjugate was used to immunize mice to produce specific mAb against rHuEPO based on hybridoma technology. The obtained F3-mAb was characterized by enzyme-linked irmnunosorbent assay （ELISA）, SDS-PAGE and Western blot. Results The isotype of F3-mAb was found to be IgM with an affinity constant of 2.1x10s L/mol. The competitive ELISA using the obtained IgM showed a broader linear range and lower detection limit compared with previous work. Conclusions The modification of rHuEPO was proved to be successful in generating required specific mAb with high avidity to rHuEPO.
文摘A new way for the synthesis of human interferon—α_A monoclonal antibody (IFN-α_A-McAb) bound to silica gel packing material in high-performance affinity chromatography (HPAFC) has been developed. The high coupling efficiency and specific activity of IFN—α_A-McAb can be obtained by activated diol-silica gel with activating agent. After purification using this packing material in HPAFC, the specific activity of recombinant human interferon-α_A (rIFN-α_A) rose up to 1.03×10~7IU/mg protein and the purification efficiency is appoximately 100 times.
基金Supported by National Natural Science Foundation of China(31100136,3111339)Independent Innovation Fund of Agricultural Science and Technology of Jiangsu Province[CX(13)3066]~~
文摘P65 protein, the major immunodominant protein of Mycoplasma hyopneu-moniae （Mhp） exhibiting no cross-reaction with other mycoplasmas, is general y used as a target protein for Mhp detection. In this study, BALB/c mice were immunized with prokaryotical y expressed P65 recombinant protein to prepare monoclonal anti-body. After screening with Mhp whole-cel protein and P65 protein, a specific hy-bridoma cel line, 3G12, was obtained by ELISA. Identification results indicated that the antibody secreted by 3G12 hybridoma cel s could react with P65 protein and Mhp whole-cel protein. According to indirect ELISA assay, 3G12 cel culture super-natant possessed a titer of 1∶12 800 against P65 protein and 1∶3 200 against Mhp whole-cel protein; 3G12 ascites possessed a titer of above 1∶4 000 000 against P65 protein and above 1∶20 000 against Mhp 168 whole-cel protein. After long-term in vitro culture and continuous freezing-thawing, 3G12 cel line could stably secrete antibodies. A monoclonal antibody against P65 protein and Mhp whole-cel protein was successful y obtained in the present study, which provided basis for further in-vestigating the pathogenic mechanism of Mhp and establishing diagnostic methods of Mycoplasmal pneumonia of swine （MPS）.
基金Chinese National Technology Researchand Development Program (863 Program,2006AA10A204)
文摘In this study, a panel of monoclonal antibodies （mAbs） against Porcine reproductive and respiratory syndrome virus（PRRSV）, named as 8C9 and4B4, were produced by fusing SP2/0 myeloma cells and spleen cells of BALB/c mice immunized with the PRRSV （TCID50=5.5）, screened by the indirect ELISA and subjected to several limiting dilutions, mAbs were then identified by biological characterization. Among the two fusion cell strains, 8C9 belonged to the IgG1 subclass and 4B4 belonged to the IgG2a subclass. The titers in cell culture supematant and abdomen liquor reached to 1：104and 1：105, respectively. The specificity test indicated that the two cells had specific reactions for the PRRSV and GP5 protein respectively, and no reaction with Classical swine fever virus （CSFV） or Swine vesicular disease virus （SVDV）. The molecular weights of the heavy chain and light chain were about 45.0 kDa and 25.0 kDa, respectively. In neutralization activity tests, the results showed that the prepared mAb 4B4 can protect 50% of cells with no CPE in dilution up to 1：512, but mAB 8C9 has no neutralization activities to PRRSV.
基金NSFC (30901116)Zhejiang Provincial Natural Science Foundation of China (Y3080212)The Planned Science and Technology Project of Zhejiang Province,China (2008C32034)
文摘The gene encoding the VP28 envelope protein of White spot syndrome virus (WSSV) was cloned into expression vector pET-30a and transformed into the Escherichia coli strain BL21.After induction,the recombinant VP28 (rVP28) protein was purified and then used to immunize Balb/c mice for monoclonal antibody (MAb) production.It was observed by immuno-electron microscopy the MAbs specific to rVP28 could recognize native VP28 target epitopes of WSSV and dot-blot analysis was used to detect natural WSSV infection.Competitive PCR showed that the viral level was approximately 104 copies/mg tissue in the dilution of gill homogenate of WSSV-infected crayfish at the detection limit of dot-blot assay.Our results suggest that dot-blot analysis with anti-rVP28 MAb could rapidly and sensitively detect WSSV at the early stages of WSSV infection.
文摘Fifteen hybridoma cell lines producing monoclonal antiboclies (McAb) against recombinant human tu-mor necrosis factor a (rhTNFa) have been established by fusing SP 2/0 cells with spleen cells from aBALB/c mouse immunized with rhTNFa. Following J M Davis’s Works, semi-solid medium was usedfor initial cloning. Five of them were studied further. Their main chromosome- numbers range were 96 to105, all of them were IgG1 subclass. The affinities of these McAbs were estimated to be 1. 25 ×108 mol/L, 1. 12×108 mol/L, 2. 34×108 mol/L, 8. 55 × 107 mol/L, 1. 04×108 mol/L, respectively.Two groups of mice challenging with E Coli (107 organisms), one group treated with 2mg/kg anti-TNF monoclonal antibody, the other did not. There was a higher survival rate in treated group, the serumTNF level was significantly lower too, and the untreated mice had severe pathologic changes in vlscera.
文摘In order to improve the clinical usefulness of mAb of mouse origin in targeting diagnosis and therapy for human brain glioma, it is necessary to humanize it and reduce its molecular size. By means of RT-PCR technique, a 348 bp heavy chain variable domain (VH),and a 318 bp light chain variable domain (VL) cDNA fragments were cloned from mouse hybridoma cell line SZ39 secreting mAb against human brain glioma. By recombinant DNA technique, the two cDNA 'fragments were linked to human IgGI heavy chain CHI and light chain K constant regions, respectively, to form a mouse/human chimeric gene which was then inserted into an expression vector pHENI-SZ39 Fab/Hu. In addition,the two cDNA fyagments were linked directly with a universal link6r and inserted into an expression vector pHENI-SZ39ScFv. The two expression vectors were separately introduced into non-suppressor E.coli HB2151to secrete chimeric antibodies and single-chain antibodies,respectively. On ELISA and Western blot assays, the two genetically engineered antibodies were bound specifically to the same 180 kD cell surface membrane antigen on human brain glioma cell line SHG44 as did the parental mAb SZ39.
文摘目的建立并验证一种检测单克隆抗体药物中重组人透明质酸酶(recombinant human hyaluronidase,rHuPH20)活性的方法。方法利用浊度法建立单克隆抗体药物中rHuPH20活性的检测方法,并对该方法的专属性、线性、中间精密度、准确度、重复性进行验证。结果该方法专属性良好,空白和不添加rHuPH20的单克隆抗体药物的rHuPH20活性均<4 U/ml。在3.5~26.7 U/ml范围内,供试品rHuPH20理论活性和实测活性线性相关,决定系数R^(2)>0.97;中间精密度试验结果的变异系数(coefficient of variation,CV)均<15%;各rHuPH20活性的平均值回收率在95%~105%之间,符合线性、中间精密度和准确度的验证要求。6次独立测定3批供试品rHuPH20活性的变异系数分别为6.56%,2.96%和4.10%,符合重复性的可接受标准(≤10%)。结论该方法各项指标均符合要求,可对单克隆抗体药物中rHuPH20活性进行质量控制。
