目的利用正电子核素^124I对人源化抗程序性死亡蛋白配体-1(programmed death ligand-1,PD-L1)的重链抗体的Fab段Nb1756进行标记并合成分子探针,通过系列基础实验评价该分子探针对于PD-L1检测的有效性和特异性。方法采用2-溴代丁二酰亚...目的利用正电子核素^124I对人源化抗程序性死亡蛋白配体-1(programmed death ligand-1,PD-L1)的重链抗体的Fab段Nb1756进行标记并合成分子探针,通过系列基础实验评价该分子探针对于PD-L1检测的有效性和特异性。方法采用2-溴代丁二酰亚胺标记^124I,获得^124I-Nb1756分子探针并进行质量控制,分析其标记率、放射化学纯度和体内外稳定性。建立结肠癌LOVO荷瘤裸鼠模型,借助Micro-PET/CT设备,评价^124I-Nb1756在上述模型动物体内和肿瘤中的分布及代谢情况。结果^124I-Nb1756标记率>99%,放射化学纯度>99%,放射化学产率为75%~80%,比活度约为11.1 MBq/nmol。Micro-PET/CT显示该分子探针在肿瘤病灶中特异性摄取,肿瘤病灶中分子探针的聚集随着时间的延长而增加。结论^124I-Nb1756分子探针制备过程简便且标记率高,该分子探针能够特异靶向肿瘤病灶中的PD-L1,并可对肿瘤进行长时间显像观察,可为选择肿瘤治疗方案提供一定帮助。展开更多
Objective: To study the preparation and characterization of monoclonal antibody (McAb) against carcinoembryonic antigen (CEA). Methods: CEA antigen was extracted from metastasized liver of patients with colorectal can...Objective: To study the preparation and characterization of monoclonal antibody (McAb) against carcinoembryonic antigen (CEA). Methods: CEA antigen was extracted from metastasized liver of patients with colorectal cancer and used for the preparation of McAb against CEA by hybridoma technique. Immunoreactivity of McAb to CEA antigen was evaluated using ELISA. Mouse ascites was purified by two steps, high performance liquid chromatography (HPLC) using protein A and high performance hydroxylapatite (HPHT). Normal adult tissues and tumor specimen were used for immunohistochemical evaluation of the McAb. Isotope 99mTc labeled CEA McAb was used for biodistribution in tumor-bearing mouse. Results: Purified CEA antigen was a glycoprotein of 180 kD. Anti-CEA McAb affinity constant was 7.4×109/M. The McAb showed positive staining in 54–88% of colorectal cancer, gastric cancer and lung cancer, while negative for normal tissues. 24 hours after injection of 99mTc labeled McAb, tumor ID%/g was higher than 15% and tumor/blood, tumor/kidney and tumor/liver were 1.82, 1.51 and 2.92 respectively. T/NT ratios of other viscera were over 3.0. Conclusion: Purified CEA antigen had very good immunogenicity. The anti-CEA McAb was highly specific. 99mTc labeled McAb was stabled both in vivo and in vitro. In vivo distribution result was satisfactory. McAb CL58 may be useful for RII and RIGS.展开更多
Monitoring dynamic changes in tumor immune markers are essential for predicting the therapeutic responses of tumors to immunotherapy, as well as other traditional therapies, such as chemotherapy and radiotherapy. Here...Monitoring dynamic changes in tumor immune markers are essential for predicting the therapeutic responses of tumors to immunotherapy, as well as other traditional therapies, such as chemotherapy and radiotherapy. Here, we designed a lipid-aptamer conjugate by employing a C18 chain to modify an aptamer targeting programmed cell death-ligand 1(C18-ap PDL1). The obtained C18-ap PDL1 could bind with serum albumin postintravenous injection to achieve prolonged blood circulation and enhanced in vivo stability without weakening its binding affinity toward PDL1. C18-ap PDL1 labeling with radionuclides, such as;Tc, could yield a nuclear imaging agent exhibiting much higher tumor-homing ability than bare aptamer. Notably, such radiolabeled C18-ap PDL1 could be utilized to visually monitor the dynamic changes in PDL1 expression postchemotherapy or radiotherapy within a few hours. Additionally, this C18-ap PDL1 could offer improved antitumor immune therapeutic responses,which are comparable with those of commercial anti-PDL1 antibodies at the same weight dosage. Thus, this article presented promising lipid-modified aptamers for cancer immunoimaging and immunotherapy.展开更多
文摘目的利用正电子核素^124I对人源化抗程序性死亡蛋白配体-1(programmed death ligand-1,PD-L1)的重链抗体的Fab段Nb1756进行标记并合成分子探针,通过系列基础实验评价该分子探针对于PD-L1检测的有效性和特异性。方法采用2-溴代丁二酰亚胺标记^124I,获得^124I-Nb1756分子探针并进行质量控制,分析其标记率、放射化学纯度和体内外稳定性。建立结肠癌LOVO荷瘤裸鼠模型,借助Micro-PET/CT设备,评价^124I-Nb1756在上述模型动物体内和肿瘤中的分布及代谢情况。结果^124I-Nb1756标记率>99%,放射化学纯度>99%,放射化学产率为75%~80%,比活度约为11.1 MBq/nmol。Micro-PET/CT显示该分子探针在肿瘤病灶中特异性摄取,肿瘤病灶中分子探针的聚集随着时间的延长而增加。结论^124I-Nb1756分子探针制备过程简便且标记率高,该分子探针能够特异靶向肿瘤病灶中的PD-L1,并可对肿瘤进行长时间显像观察,可为选择肿瘤治疗方案提供一定帮助。
基金supported by a grant from The National "863" Project of China(No.2001AA215371)
文摘Objective: To study the preparation and characterization of monoclonal antibody (McAb) against carcinoembryonic antigen (CEA). Methods: CEA antigen was extracted from metastasized liver of patients with colorectal cancer and used for the preparation of McAb against CEA by hybridoma technique. Immunoreactivity of McAb to CEA antigen was evaluated using ELISA. Mouse ascites was purified by two steps, high performance liquid chromatography (HPLC) using protein A and high performance hydroxylapatite (HPHT). Normal adult tissues and tumor specimen were used for immunohistochemical evaluation of the McAb. Isotope 99mTc labeled CEA McAb was used for biodistribution in tumor-bearing mouse. Results: Purified CEA antigen was a glycoprotein of 180 kD. Anti-CEA McAb affinity constant was 7.4×109/M. The McAb showed positive staining in 54–88% of colorectal cancer, gastric cancer and lung cancer, while negative for normal tissues. 24 hours after injection of 99mTc labeled McAb, tumor ID%/g was higher than 15% and tumor/blood, tumor/kidney and tumor/liver were 1.82, 1.51 and 2.92 respectively. T/NT ratios of other viscera were over 3.0. Conclusion: Purified CEA antigen had very good immunogenicity. The anti-CEA McAb was highly specific. 99mTc labeled McAb was stabled both in vivo and in vitro. In vivo distribution result was satisfactory. McAb CL58 may be useful for RII and RIGS.
基金supported by the National Natural Science Foundation of China (32101149, 91959104, 21927803, 52032008, 51903182, 51572180)the China Postdoctoral Science Foundation (2020M671143)+3 种基金a Project Funded by the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions, Jiangsu Social Development Project (BE2019658)Suzhou Key Laboratory of Nanotechnology and BiomedicineCollaborative Innovation Center of Suzhou Nano Science & Technologythe Program of Introducing Talents of Discipline to Universities of China。
文摘Monitoring dynamic changes in tumor immune markers are essential for predicting the therapeutic responses of tumors to immunotherapy, as well as other traditional therapies, such as chemotherapy and radiotherapy. Here, we designed a lipid-aptamer conjugate by employing a C18 chain to modify an aptamer targeting programmed cell death-ligand 1(C18-ap PDL1). The obtained C18-ap PDL1 could bind with serum albumin postintravenous injection to achieve prolonged blood circulation and enhanced in vivo stability without weakening its binding affinity toward PDL1. C18-ap PDL1 labeling with radionuclides, such as;Tc, could yield a nuclear imaging agent exhibiting much higher tumor-homing ability than bare aptamer. Notably, such radiolabeled C18-ap PDL1 could be utilized to visually monitor the dynamic changes in PDL1 expression postchemotherapy or radiotherapy within a few hours. Additionally, this C18-ap PDL1 could offer improved antitumor immune therapeutic responses,which are comparable with those of commercial anti-PDL1 antibodies at the same weight dosage. Thus, this article presented promising lipid-modified aptamers for cancer immunoimaging and immunotherapy.
