本文报道利用^(125)I 标记的抗 CD_7抗原决定簇的单抗 3A_1,在人 T 淋巴瘤裸鼠模型及人鼻咽癌裸鼠模型体内进行生物学分布和显像研究。注射标记抗体26小时后,淋巴瘤裸鼠模型中出现肿瘤显像。96小时后处死裸鼠,测定肿瘤及各器官中的放射...本文报道利用^(125)I 标记的抗 CD_7抗原决定簇的单抗 3A_1,在人 T 淋巴瘤裸鼠模型及人鼻咽癌裸鼠模型体内进行生物学分布和显像研究。注射标记抗体26小时后,淋巴瘤裸鼠模型中出现肿瘤显像。96小时后处死裸鼠,测定肿瘤及各器官中的放射性分布,结果表明 McAb 3A_1在 CEM 荷瘤裸鼠的肿瘤组织中有特异性的浓集。^(125)I 标记的对照抗体,鼠抗乙型肝炎病毒核心抗原抗体,在 T 淋巴瘤裸鼠模型的肿瘤部位无明显浓集。展开更多
Objective.Using monoclonal antibody (mAb) Fab′ fragment to develop mAb immunoconjugates for cancer. Methods.Fab′ fragment of mAb 3A5 was prepared by digestion of the antibody with pepsin and then reduced by dithioth...Objective.Using monoclonal antibody (mAb) Fab′ fragment to develop mAb immunoconjugates for cancer. Methods.Fab′ fragment of mAb 3A5 was prepared by digestion of the antibody with pepsin and then reduced by dithiothreitol (DTT),while Fab′ fragment of mAb 3D6 was obtained by digestion of the antibody with ficin and subsequently reduced by β mercaptoethanol.The conjugation between Fab′ fragment and pingyangmycin (PYM),an antitumor antibiotic,was mediated by dextran T 40.Immunoreactivity of Fab′ PYM conjugates with cancer cells was determined by ELISA,and the cytotoxicity of those conjugates to cancer cells was determined by clonogenic assay.Antitumor effects of the Fab′ PYM conjugates were evaluated by subcutaneously transplanted tumors in mice. Results.The molecular weight of Fab′ fragment was approximately 53 kD,while the average molecular weight of Fab′ PYM conjugate was 170 kD.The Fab′ PYM conjugates showed immunoreactivity with antigen relevant cancer cells and selective cytotoxicity against target cells.Administered intravenously,Fab′ PYM conjugates were more effective against the growth of tumors in mice than free PYM and PYM conjugated with intact mAb. Conclusion.Fab′ PYM conjugate may be capable of targeting cancer cells and effectively inhibiting tumor growth,suggesting its therapeutic potential in cancer treatment.展开更多
AIM: To investigate the role of SCCA2 and other SCCA1 molecules in the process of hepatitis B virus (HBV) binding to mammalian cells.METHODS: SCCA1 and SCCA2 were isolated from HepG2. Binding protein (BP) genes were ...AIM: To investigate the role of SCCA2 and other SCCA1 molecules in the process of hepatitis B virus (HBV) binding to mammalian cells.METHODS: SCCA1 and SCCA2 were isolated from HepG2. Binding protein (BP) genes were obtained through PCR. Recombinant baculoviruses expressing SCCA1, SCCA2, BP, and different mutants were constructed and utilized to infect mammalian cells to investigate the binding ability of infected cells to HBV.RESULTS: A SCCA1 gene (A1) was isolated from HepG2, but it appeared to lack the binding ability of infected cells to HBV. Two mutants, A1-BP and BP-A1, were constructed by interchanging the carboxyl terminal of A1 and BP. Cells expressing A1-BP showed an increased virus bindingcapacity, but not BP-A1. Comparison of A1 sequence with the sequence of BP indicated the presence of only three amino acid changes in the carboxyl terminal, two of them were found in the reactive site loop (RSL) of SCCA1. Primary structure assay revealed that the hydrophobicity of BP and AJ515706 in this domain was strong, but A1 was relatively weak. Changing the aa349 of A1 from low hydrophobic glutamic acid to high hydrophobic valine enhanced HBV binding. In contrast, HBV binding was reduced by changing the aa349 of BP from valine to glutamic acid. CONCLUSION: The reslts suggest that the hydrophobicity of RSL of SCCA1 may play an important role in HBV binding to cells.展开更多
文摘本文报道利用^(125)I 标记的抗 CD_7抗原决定簇的单抗 3A_1,在人 T 淋巴瘤裸鼠模型及人鼻咽癌裸鼠模型体内进行生物学分布和显像研究。注射标记抗体26小时后,淋巴瘤裸鼠模型中出现肿瘤显像。96小时后处死裸鼠,测定肿瘤及各器官中的放射性分布,结果表明 McAb 3A_1在 CEM 荷瘤裸鼠的肿瘤组织中有特异性的浓集。^(125)I 标记的对照抗体,鼠抗乙型肝炎病毒核心抗原抗体,在 T 淋巴瘤裸鼠模型的肿瘤部位无明显浓集。
基金This work was supported by the grants from the National Key Research Project Funds，国家重点基础研究发展计划(973计划)
文摘Objective.Using monoclonal antibody (mAb) Fab′ fragment to develop mAb immunoconjugates for cancer. Methods.Fab′ fragment of mAb 3A5 was prepared by digestion of the antibody with pepsin and then reduced by dithiothreitol (DTT),while Fab′ fragment of mAb 3D6 was obtained by digestion of the antibody with ficin and subsequently reduced by β mercaptoethanol.The conjugation between Fab′ fragment and pingyangmycin (PYM),an antitumor antibiotic,was mediated by dextran T 40.Immunoreactivity of Fab′ PYM conjugates with cancer cells was determined by ELISA,and the cytotoxicity of those conjugates to cancer cells was determined by clonogenic assay.Antitumor effects of the Fab′ PYM conjugates were evaluated by subcutaneously transplanted tumors in mice. Results.The molecular weight of Fab′ fragment was approximately 53 kD,while the average molecular weight of Fab′ PYM conjugate was 170 kD.The Fab′ PYM conjugates showed immunoreactivity with antigen relevant cancer cells and selective cytotoxicity against target cells.Administered intravenously,Fab′ PYM conjugates were more effective against the growth of tumors in mice than free PYM and PYM conjugated with intact mAb. Conclusion.Fab′ PYM conjugate may be capable of targeting cancer cells and effectively inhibiting tumor growth,suggesting its therapeutic potential in cancer treatment.
基金Supported by the Cross-Century Talent Training Program of Ministry of Education, China
文摘AIM: To investigate the role of SCCA2 and other SCCA1 molecules in the process of hepatitis B virus (HBV) binding to mammalian cells.METHODS: SCCA1 and SCCA2 were isolated from HepG2. Binding protein (BP) genes were obtained through PCR. Recombinant baculoviruses expressing SCCA1, SCCA2, BP, and different mutants were constructed and utilized to infect mammalian cells to investigate the binding ability of infected cells to HBV.RESULTS: A SCCA1 gene (A1) was isolated from HepG2, but it appeared to lack the binding ability of infected cells to HBV. Two mutants, A1-BP and BP-A1, were constructed by interchanging the carboxyl terminal of A1 and BP. Cells expressing A1-BP showed an increased virus bindingcapacity, but not BP-A1. Comparison of A1 sequence with the sequence of BP indicated the presence of only three amino acid changes in the carboxyl terminal, two of them were found in the reactive site loop (RSL) of SCCA1. Primary structure assay revealed that the hydrophobicity of BP and AJ515706 in this domain was strong, but A1 was relatively weak. Changing the aa349 of A1 from low hydrophobic glutamic acid to high hydrophobic valine enhanced HBV binding. In contrast, HBV binding was reduced by changing the aa349 of BP from valine to glutamic acid. CONCLUSION: The reslts suggest that the hydrophobicity of RSL of SCCA1 may play an important role in HBV binding to cells.
