小鼠B7-H4重组腺病毒的构建及鉴定

目的:利用AdEasyTM XL system构建携带小鼠B 7-H4基因的重组腺病毒,并鉴定其生物学活性.方法:以RT-PCR方法从C5 7小鼠肺组织中扩增B7-H4全长基因并克隆到T载体,然后测序鉴定.经Xhol Ⅰ和EcoR Ⅴ双 酶切后接入pshuttle-CMV穿梭载体(简称PSC),构建重组腺病毒的穿梭质粒PSC-mB7-H4 ,并电转化至BJ5183-AD-1感受态细菌,经筛选获得携带mB7-H4的重组腺病毒的质粒pmB7 -H4/Ad.将此质粒转化人胚肾细胞(AD-293)产生复制缺陷的重组腺病毒mB7-H4/Ad .以RT-PCR及Western blot方法检测被mB7-H4/Ad感染的AD-293细胞中B7-H4 mRNA和蛋 白的表达,并观察重组腺病毒感染的小鼠成纤维细胞(L929)对T细胞增殖和细胞因子表达的影响. 结果:获得序列准确的mB7-H4基因并成功构建重组腺病毒表达质 粒,转化AD-293细胞获得重组腺病毒;细胞生物学实验证实,该重组腺病毒具有抑制CD3单抗诱导的T淋巴细胞的增殖和细胞因子的分泌. 结论:成功构建具有免疫抑制功能的mB7-H4重组腺病毒.

Construction and identification of recombinant adenoviral vector encoding B7-H4 gene

OBJECTIVE: To construct the recombinant adenovirus containing B7-H4 gene with AdEasy XL system and to identify its biological activities. METHODS: The full-length mouse B7-H4 gene was amplified by RT-PCR from C57 mouse lung and put into T vector, then verified by sequencing. Digested with Xhol I and EcoR V the B7-H4 gene was inserted into pshuttle-CMW(PSC). Pme I linearized shuttle plasmid was transformed into E.coli BJ5183-AD-1 to obtain the recombinant adenoviral plasmid pAd-mB7-H4 by efficient homologous recombination. Then the recombinant adenovirus-mB7-H4/Ad was obtained by packaging Pac I linearized in D-293 cells. The mRNA and protein expression of B7-H4 in mB7-H4/Ad infected AD-293 cells were detected by RT-PCR and Western blot, respectively. mB7-H4/Ad was used to infect L929 cells, the bioactivity of expressed B7-H4 in stimulation of T lymphocytes proliferation and cytokine production were tested. RESULTS: The full-length of mB7-H4 was cloned from mouse lung tissue cDNA and verified by sequencing. The recombinant plasmid pAd-m B7-H4 was successfully generated by homologous recombination, and the primary mB7-H4/Ad was obtained by packaging pAd-B7-H4 in AD-293 cells. Compared with the negative control, L929 cells infected with mB7-H4/Ad effectively inhibited the proliferation of T lymphocytes and cytokines production. CONCLUSION: The bioactive recombinant adenovirus mB7-H4/Ad has been successfully constructed.