重叠延伸拼接法

Objective:To analyse the McAb anti blood group A substance secreted by 50A hybridoma at molecular level and then lay the foundation for preparation of the reagent used for blood grouping of new generations genetic engineering antibody.

从杂交瘤细胞提取总RNA，经RT－PCR扩增、克隆抗体的轻、重链可变区基因，用PCR及双脱氧核苷酸链终止法分析其核苷酸序列，采用PCR技术重叠延伸拼接法构建50A单抗单链抗体基因。

The PSCA_3 fragment was selected for its superior expression level in eukaryotic cells.Then the sig-PSCA_3-Fc-GPI genetic fragment was cloned into pVAX1-neo-IRES-GM/B7 vector to construct the final immunological inhanced DNA vaccine pVAX1-PSCA_3-FcGB. Immunofluorescence and flow cytometry were used to confirm the expression of PSCA_3 fragment by transfected into Cos7 cell.Finally,the anti-tumor effect of pVAX1-PSCA_3-FcGB was tested in murine prostate cancer model generated by RM-1 cell line.The animal was immunized with pVAX1-PSCA_3-FcGB DNA vaccine by intramuscular injection plus electroporation,pVAX1 and pVAX1-PSCA_1-FcGB plasmid were used as control.The inhibitory effect of tumor was investigated by observion of forming time,volume and inhibition ratio of tumor.Results:DNA sequencing conformed that the heterological PSCA fusion antigen fragment which was synchronized by overlapping-extending-PCR,was consistent to design.Enzyme digestion analysis showed that the 1 to 4 copies heterological PSCA fusion antigen fragments were constructed successfully.

方法(1)检索GenBank，选择包含人主要T细胞抗原表位序列的人PSCA基因片段，应用异种化抗原设计技术，保留人T细胞抗原表位，设计异种化PSCA融合抗原片段；(2)根据核酸序列按中心模板法设计引物，应用重叠延伸PCR技术拼接合成异种化PSCA融合抗原片段基因，以PCR、限制性酶切和DNA序列测定法进行鉴定：(3)利用DNA限制性内切酶BssHⅡ和MluⅠ酶切后粘端互补的特点，采用同尾酶法构建1—4拷贝异种化PSCA融合抗原片段(PNCA_1-PSCA_4)，并将上述片段分别插入真核表达载体pCI-neo-Fc-GPI中，转染293T细胞，借助免疫荧光+流式细胞术考察插入片段表达效率，最终选定PSCA_3片段进行下一步研究；(4)将sig-PSCA_3-Fc-GPI基因片段自pCI-PSCA_3-Fc-GPI质粒上切下，插入pVAX1-neo-IRES—GM/B7载体中，构建免疫增效DNA疫苗pVAX1-PSCA_3-FcGB，并应用转染Cos7细胞+免疫荧光/流式细胞术方法鉴定其在真核细胞中的表达情况；(5)给8周龄雄性C57BL/6小鼠皮下种植RM-1细胞，制备小鼠前列腺癌模型，并采用股四头肌肌肉注射+电脉冲法(Electroporation，EP)接种DNA疫苗质粒pVAX1-PSCA_3-FcGB，同时接种pVAX1空载体质粒和pVAX1-PSCA_1-FcGB质粒作为对照，通过观察计算免疫动物的成瘤时间、肿瘤体积和抑瘤率，来评价该DNA疫苗在小鼠体内的抑瘤效果。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。