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目的 该研究旨在利用噬菌体展示技术,构建小儿呼吸道合胞病毒感染患者人源性噬菌体抗体库,搭建人源性抗体制备的技术平台.解决鼠源性单克隆抗体临床应用的不足,为小儿呼吸道合胞病毒感染发病机制的研究、诊断、治疗和预防提供新的有效途径.方法 从52例呼吸道合胞病毒感染患儿外周血淋巴细胞中提取总RNA,并逆转录为cDNA.用PCR扩增轻链和重链Fd段(即重链的可变区和第一恒定区)基因,并将扩增的轻链和重链基因片段克隆于pComb3x噬粒载体,电转化XL1-Blue大肠杆菌,经辅助噬菌体M13K07超感染后构建成Fab段噬菌体抗体库.对此抗体库双酶切进行鉴定,并用呼吸道合胞病毒颗粒作抗原进行初步筛选.结果 经过重轻链基因的重组,成功构建一免疫噬菌体抗体基因库,共有2.08×107个不同的克隆菌,其中70%的克隆均含有轻链和重链Fd基因.因此,所构建的噬菌体抗体库的库容量为1.46×107,经过滴定,原始抗体库的滴度为1.06×1012 pfu/mL.经初步筛选,抗体库得到了不同程度的富集.结论 利用基因重组技术和噬菌体展示技术,成功构建了小儿呼吸道合胞病毒感染患者人源性Fab噬菌体抗体库,为人源性单克隆抗体的制备提供了良好的条件,为进一步的研究奠定了基础,亦将有益于小儿呼吸道合胞病毒感染的诊断、治疗和预防.“,”Objective To construct a human phage display antibody library,which will help to develop new drugs and vaccines against respiratory syncytial virus (RSV) and solve many of the issues that have limited the progression and application of murine monoclonal antibodies (McAbs) in the clinic.This can provide a platform for human antibody preparation and diagnosis,prophylaxis and therapy of RSV infection in children.Methods Peripheral blood lymphocytes were isolated from 52 children with RSV infection,cDNA was synthesized from the total RNA of lymphocytes.The light and heavy chain Fd (VH-CH1)fragments of immunoglobulin gene were amplified by RT-PCR.The amplified products were cloned into phagemid vector pComb3x and the clone samples were electrotransformed into competent E.coli XL1-Blue.The transformed cells were then infected with M13K07 helper phage to yield recombinant phage antibody of Fabs.The plasmids extracted from amplified E.coil were digested with restriction endonucleases Sac 1,Xba I,Spe I and Xho I to monitor the insertion of the light or heavy chain Fd genes.RSV virions were utilized as antigens to screen Fab antibodies.Results By recombination of light and heavy chain genes,an immune Fab phage display antibody library against RSV containing 2.08×107 different clones was constructed,in which 70% clones had light chains and heavy chain Fd genes.The capacity of Fab phage antibody gene library was 1.46×107 and the titre of the original Fab antibody library was about 1.06 x 1012 pfu/mL The antibody library gained an enrichment in different degrees after the preliminary panning.Condusions Utilizing the technology of phage display,an immune Fab phage display antibody library against RSV was successfully constructed in this study,which laid a valuable experimental foundation for further study and created favorable conditions for preparing human McAbs. This may also contribute to the improvement in the diagnosis,therapy and prophylaxis of RSV infection in children.