【摘要】 目的构建淋病奈瑟球菌表面蛋白A(NspA)基因疫苗,并接种小鼠,评价其诱导的体液和细胞免疫应答。方法将NspA基因插入到真核表达载体pcDNA3.1(+)中,构建重组真核表达质粒pcDNA3.1(+)/NspA,并经PCR、双酶切及测序鉴定。反转录-聚合酶链反应(RT-PCR)和免疫组织化学法分别检测NspA基因转染细胞后mRNA和蛋白的表达。以pcDNA3.1(+)/NspA重组质粒免疫45只雄性BALB/c小鼠,试管凝集法检测免疫小鼠抗体滴度,EIASA检测IFN-γ水平,四甲基偶氮唑蓝(MTT)比色法检测脾淋巴细胞增殖。提取接种部位股四头肌总DNA,PCR检测BALB/c小鼠肌细胞内NspA基因。结果成功构建pcDNA3.1(+)/NspA基因疫苗,能在真核细胞中转录和表达。pcDNA3.1(+)/NspA免疫组的抗体滴度达1:640,pcDNA3.1(+)和PBS免疫组均无特异性抗体检出。空载体pcDNA3.1(+)组IFN-γ为(23.79±11.85)pg/mL,pcDNA3.1(+)/ NspA免疫组为(169.71±30.52)pg/mL(P<0.01);脾淋巴细胞增殖的刺激指数(SI)分别为1.05±0.30和1.94±0.74(P<0.01)。并证实NspA基因可在小鼠肌细胞中稳定存在。结论构建淋病奈瑟球菌NspA基因疫苗,将其免疫BALB/c小鼠可诱导特异性体液和细胞免疫应答,为进一步用于淋病预防奠定了基础。更多还原

【Abstract】 Objective To construct the Neisseria surface protein A (NspA) DNA vaccine of Neisseria gonorrhoeae and evaluate the humoral and cellular immune responses induced by this vaccine in mice model.Methods The recombinant expression vector pcDNA3.1 (+)/NspA was constructed by inserting NspA gene into the eukaryotic expression vector pcDNA3.1 (+) and confirmed by poly merase chain reaction (PCR),restriction enzymes HindⅢ,XbaⅠand DNA sequencing.NspA mR- NA in transfected RAW264.7 cells and NspA protein expression in transfected COS-7 cells were de- tected by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical stai- ning,respectively.Forty-five male BALB/c mice were immunized with pcDNA3.1 (+)/NspA recom binant plasmid.The level of serum anti-Neisseria gonorrhoeae antibody of the immunized mice was detected by tube agglutination test,and the level of interieron (IFN)-γwas assayed by enzyme-linked immunosorbent assay (ELISA).The proliferation of splenocytes was determined by methyl thiazolyl tetrazolium (MTT) colormetry.The NspA gene in BALB/c mice was identified by PCR with the total DNA extracted from quadriceps femoris in immunized sites.Results Restriction enzymes digestion a- nalysis and DNA sequencing results revealed that the pcDNA3.1 (+)/NspA had been constructed successfully.NspA gene had been transcripted and expressed in mammalian cells.The peak titer of specific antibody was 1:640 in pcDNA3.1(+)/NspA immunized group and there was no specific an- tibody detected in both pcDNA3.1 (+) immunized group and PBS group.The IFN-γlevel in pcD NA3.1 (+) immunized group was (23.79±11.85)pg/mL and that in pcDNA3.1 (+)/NspA immu- nized group was(169.71±30.52)pg/mL (P<0.01).The stimulation index (SI) of the splenocyte proliferation was 1.05±0.30和1.94±0.74(P<0.01) in pcDNA3.1(+) and pcDNA3.1(+)/NspA immunized group,respectively.The NspA gene could be detected in the muscle cells.Conclusions NspA gene vaccine is successfully constructed,which can induce specific humoral and cellular immune responses in immunized BALB/c mice model.These findings will be beneficial to the prevention of gonorrhea.更多还原