AIM： Passive immunotherapy using antibody against hepatitis B surface antigen （HBsAg） has been advocated in certain cases of Hepatitis B infection. We had earlier reported on the cloning and expression of a high af...AIM： Passive immunotherapy using antibody against hepatitis B surface antigen （HBsAg） has been advocated in certain cases of Hepatitis B infection. We had earlier reported on the cloning and expression of a high affinity scFv derived from a mouse monoclonal （5S） against HBsAg. However this mouse antibody cannot be used for therapeutic purposes as it may elicit anti-mouse immune responses. Chimerization by replacing mouse constant domains with human ones can reduce the immunogenicity of this antibody.METHODS： We cloned the VH and V, genes of this mouse antibody, and fused them with CH1 domain of human IgG1 and C, domain of human kappa chain respectively. These chimeric genes were cloned into a phagemid vector. After initial screening using the phage display system, the chimeric Fab was expressed in soluble form in E. coli.RESULTS： The chimeric Fab was purified from the bacterial periplasmic extract. We characterized the chimeric Fab using several in vitro techniques and it was observed that the chimeric molecule retained the high affinity and specificity of the original mouse monoclonal. This chimeric antibody fragment was further expressed in different strains of E. coli to increase the yield.CONCLUSION： We have generated a mouse-human chimeric Fab against HBsAg without any significant loss in binding and epitope specificity. This chimeric Fab fragment can be further modified to generate a fulllength chimeric antibody for therapeutic uses.展开更多
目的了解北京市通州区2021―2022年新报告Ⅰ型人类免疫缺陷病毒(human immunodeficiency virus type 1,HIV-1)感染者新发感染状况及人群分布特征。方法采用限制性抗原亲和力法,对通州区2021—2022年艾滋病确证实验室经免疫印迹法确证为H...目的了解北京市通州区2021―2022年新报告Ⅰ型人类免疫缺陷病毒(human immunodeficiency virus type 1,HIV-1)感染者新发感染状况及人群分布特征。方法采用限制性抗原亲和力法,对通州区2021—2022年艾滋病确证实验室经免疫印迹法确证为HIV-1抗体阳性的样本进行新发感染检测。采用χ^(2)检验分析2021―2022年通州区新报告HIV-1感染者新发感染人口学特征,采用二元logistic回归分析评价免疫印迹带型与化学发光COI(cut off index)值在预测HIV-1新发感染中的价值。结果北京市通州区2021―2022年新报告HIV-1感染者308例,新发感染127例,新发感染比例为41.23%。308例通州区新报告HIV-1感染者中,<30岁(新发感染比例为50.89%)、未婚/离异/丧偶(新发感染比例为44.58%)、大专及以上(新发感染比例为46.20%)、无性病史者(新发感染比例为44.75%)的新发感染比例较高,差异有统计学意义(χ^(2)值分别为7.414、5.563、6.057、3.865,P均<0.05)。不同性别、传播途径、户籍新报告HIV-1病例新发感染比例差异无统计学意义。免疫印迹带型中,p31条带缺失[记作p31(-)](OR=4.361,95%CI:1.529~12.439)、gp41条带缺失[记作gp41(-)](OR=14.542,95%CI:4.285~49.359)易被判定为新发感染,化学发光检测COI值<150的样本被判定为新发感染的可能性是COI值≥150样本的4.072倍。结论2021―2022年通州区新报告HIV-1感染者的新发感染比例均处于高位水平。进一步加强宣传干预措施对区域性疫情防控有重要意义。免疫印迹带型p31(-)、gp41(-),化学发光检测COI值<150在预测HIV-1新发感染中有指示作用。展开更多
基金Supported by the Department of Biotechnology (DBT), Govt. of India, NO. BT/PR2540/PID/25/101/2001
文摘AIM： Passive immunotherapy using antibody against hepatitis B surface antigen （HBsAg） has been advocated in certain cases of Hepatitis B infection. We had earlier reported on the cloning and expression of a high affinity scFv derived from a mouse monoclonal （5S） against HBsAg. However this mouse antibody cannot be used for therapeutic purposes as it may elicit anti-mouse immune responses. Chimerization by replacing mouse constant domains with human ones can reduce the immunogenicity of this antibody.METHODS： We cloned the VH and V, genes of this mouse antibody, and fused them with CH1 domain of human IgG1 and C, domain of human kappa chain respectively. These chimeric genes were cloned into a phagemid vector. After initial screening using the phage display system, the chimeric Fab was expressed in soluble form in E. coli.RESULTS： The chimeric Fab was purified from the bacterial periplasmic extract. We characterized the chimeric Fab using several in vitro techniques and it was observed that the chimeric molecule retained the high affinity and specificity of the original mouse monoclonal. This chimeric antibody fragment was further expressed in different strains of E. coli to increase the yield.CONCLUSION： We have generated a mouse-human chimeric Fab against HBsAg without any significant loss in binding and epitope specificity. This chimeric Fab fragment can be further modified to generate a fulllength chimeric antibody for therapeutic uses.
文摘目的了解北京市通州区2021―2022年新报告Ⅰ型人类免疫缺陷病毒(human immunodeficiency virus type 1,HIV-1)感染者新发感染状况及人群分布特征。方法采用限制性抗原亲和力法,对通州区2021—2022年艾滋病确证实验室经免疫印迹法确证为HIV-1抗体阳性的样本进行新发感染检测。采用χ^(2)检验分析2021―2022年通州区新报告HIV-1感染者新发感染人口学特征,采用二元logistic回归分析评价免疫印迹带型与化学发光COI(cut off index)值在预测HIV-1新发感染中的价值。结果北京市通州区2021―2022年新报告HIV-1感染者308例,新发感染127例,新发感染比例为41.23%。308例通州区新报告HIV-1感染者中,<30岁(新发感染比例为50.89%)、未婚/离异/丧偶(新发感染比例为44.58%)、大专及以上(新发感染比例为46.20%)、无性病史者(新发感染比例为44.75%)的新发感染比例较高,差异有统计学意义(χ^(2)值分别为7.414、5.563、6.057、3.865,P均<0.05)。不同性别、传播途径、户籍新报告HIV-1病例新发感染比例差异无统计学意义。免疫印迹带型中,p31条带缺失[记作p31(-)](OR=4.361,95%CI:1.529~12.439)、gp41条带缺失[记作gp41(-)](OR=14.542,95%CI:4.285~49.359)易被判定为新发感染,化学发光检测COI值<150的样本被判定为新发感染的可能性是COI值≥150样本的4.072倍。结论2021―2022年通州区新报告HIV-1感染者的新发感染比例均处于高位水平。进一步加强宣传干预措施对区域性疫情防控有重要意义。免疫印迹带型p31(-)、gp41(-),化学发光检测COI值<150在预测HIV-1新发感染中有指示作用。
