树突状细胞在沙门氏菌感染获得性免疫中的作用

树突状细胞（DC）在沙门氏菌入侵部位存在,并具有从上皮细胞组织向次级淋巴器官迁移的能力,加之具有激活幼稚型T细胞的功能,DC的这些特性决定了它们在启动针对沙门氏菌感染的获得性免疫应答的过程中将发挥关键作用.本文就DC在沙门氏感染获得性免疫中的作用作一综述.     

鸡IL-2、IL-1 8、IFN-γ cDNA和CpG DNA在减毒沙门菌运送H5亚型禽流感DNA疫苗中的佐剂作用

目的 探讨鸡IL-2、IL-18、IFN-γ cDNA和CpG DNA在减毒沙门菌运送H5亚型禽流感DNA疫苗中的佐剂作用。方法 将携带禽流感病毒（AIV）DNA疫苗的重组沙门菌SL7207（pVAX1-HA-IL2）、SL7207（pVAX1-HA—IL18）、SL7207（pVAXt—HA—IFN-γ）、SL7207（pVAX1—HA—CpG）、SL7207（pVAX1-HA）和SL7207（pVAX1）经口服和滴鼻途径首免1日龄商品代伊莎褐蛋鸡，测定免疫鸡的体液和黏膜免疫应答水平，并进行攻毒保护试验。结果 二免后3周，SL7207（pVAX1-HA—CpG）、SL7207（pVAX1-HA-IFN-γ）免疫组以及SL7207（pVAX1-HA）和SL7207（pVAX1-IFN-7）联合免疫组鸡产生了较高水平的特异性黏膜免疫应答（P〈0．05），但重组菌免疫鸡血清中抗AIV HI抗体水平与空载体组相比差异无统计学意义。SL7207（pVAX1-HA-CpG）、SL7207（pVAX1-HA—IFN-7）的免疫保护指数显著高于阴性对照组。结论 初步观察佐剂效应依次为：CpG〉IFN-7〉IL-18，IL-2未表现出佐剂效应。     

小鼠骨髓源性树突状细胞的体外诱导

分离树突状细胞（DC）的原理是依据DC的低密度和半黏附特性，DC缺乏Fc受体，可对获得的DC进一步纯化。这种方法获取的DC数量有限。细胞因子诱生法是目前体外扩增DC常用的方法。其中，扩增效果最好的细胞因子是粒细胞-巨噬细胞集落刺激因子（GM—CSF）和白细胞介素4（IL-4）。     

口服鼠疫F1-V重组融合基因DNA活菌疫苗的构建及免疫原性研究

目的 构建携带鼠疫耶尔森菌F1-V融合基因的重组减毒沙门菌苗,口服免疫Balb/c小鼠检测其免疫原性,为口服鼠疫活载体DNA疫苗研究打下基础.方法 将F1-V融合基因克隆到真核表达载体asd-pVAX1,进一步依次将重组质粒转化减毒沙门菌X3730、X4550得到重组沙门菌X4550(asd-pVAX1/F1-V),提取重组质粒转染COS-7细胞并做免疫组化和Western-blot检测F1-V融合蛋白在细胞中的表达.以1×109CFU/只的剂量3次口服免疫Balb/c小鼠,ELISA方法检测血清中抗体水平.结果 构建的重组减毒沙门菌转染COS-7细胞后,免疫组化和Western-blot试验证明F1-V融合蛋白在细胞中得到了瞬时表达,ELISA检测到免疫小鼠血清有特异性抗体IgG产生.结论 构建的重组沙门菌能运送DNA疫苗到体内并成功释放质粒刺激机体产生特异性免疫应答,为口服鼠疫活载体DNA疫苗的黏膜免疫研究打下了基础.     

我国地方品种鸡IL-17cDNA的克隆、表达及鉴定

目的:克隆我国地方品种鸡IL-17 cDNA,构建该基因的原核表达质粒,获得融合表达蛋白并鉴定其免疫特性。方法:利用特异性引物,通过RT-PCR方法扩增得到隐性白羽鸡IL-17(ChIL-17)的基因片段,PCR产物克隆至原核表达载体pGEX-6P-1中,构建重组表达质粒pGEX-6P-1-ChIL17。将重组质粒pGEX-6P-1-ChIL17转化E.coliBL21,IPTG诱导表达目的蛋白,应用SDS-PAGE和Western blot分析鉴定表达产物。结果:成功扩增出ChIL-17基因片段,大小约510 bp,序列与GenBank登录的序列(NM 204460)相比,核苷酸同源性为99.8%,第477位碱基由G变为A,氨基酸同源性为100%。酶切鉴定结果表明,ChIL-17基因正确克隆入原核表达载体pGEX-6P-1中。重组质粒pGEX-6P-1-ChIL17在大肠杆菌中获得表达,SDS-PAGE结果显示出Mr约46 000大小的目的蛋白表达条带;Western blot结果表明,表达产物与小鼠IL-17抗体具有良好的反应性。结论:成功克隆并表达出我国地方品种鸡ChIL-17基因,为抗ChIL-17单...     

重组沙门菌表达结核分枝杆菌ESAT-6及其特异性免疫应答分析

Objective To determine the immune responses induced by recombinant Salmonella ty-phimurium expressing the secreting antigen ESAT-6 of Mycobacterium tuberculosis. Methods ESAT-6 cod-ing gene was cloned and identified by PCR and sequencing. Prokaryotic expression plasmid pYA33-esat car-rying the ESAT-6 coding sequence was constructed firstly and electro-transformed into an attenuated strain X4550 of Salmonella typhimurium, the recombinant bacteria was named as X4550(33-esat). C57BL/6 mice were immunized intranasally (I. N) with 108 CFU recombinant bacteria at day 0 and 18. Cells from spleen, lung, mesenteric lymph node (MLN) and Peyer's patch (PP) were collected from mice after second immu-nization, and the specific IFN-γ-secreting cells and IL-4-secreting cells were detected by ELISPOT assay u-sing ESAT-6 peptide as stimulus. Furthermore, CTL effects were in vivo evaluated by CFSE assay. Results The results showed that cellular immune responses specific for ESAT-6 could be detected by ELISPOT assay. In lung and PP cells, immune responses against ESAT-6 were biased toward Th1 type, the frequency of IFN-γ-secreting cells was much higher than that of IL-4-secreting cells. In splenocytes and MLN cells, the anti-gen specific immune responses acted as Thl and Th2 balance, the frequency of IFN-γ-secreting cells was close to that of IL-4-secreting cells. CFSE assay indicated that recombinant bacteria could induce the high level of CTL effects specific for ESAT-6 peptide. Conclusion These results suggested that recombinant Sal-monella typhimurium X4550(33-esat) not only can induce cellular immune responses, but also can elicit specific CTL responses after I. N immunization. It also provided the useful information for the control of infec-tious disease of tuberculosis.     

重组沙门菌表达结核分枝杆菌ESAT-6及其特异性免疫应答分析

Objective To determine the immune responses induced by recombinant Salmonella ty-phimurium expressing the secreting antigen ESAT-6 of Mycobacterium tuberculosis. Methods ESAT-6 cod-ing gene was cloned and identified by PCR and sequencing. Prokaryotic expression plasmid pYA33-esat car-rying the ESAT-6 coding sequence was constructed firstly and electro-transformed into an attenuated strain X4550 of Salmonella typhimurium, the recombinant bacteria was named as X4550(33-esat). C57BL/6 mice were immunized intranasally (I. N) with 108 CFU recombinant bacteria at day 0 and 18. Cells from spleen, lung, mesenteric lymph node (MLN) and Peyer's patch (PP) were collected from mice after second immu-nization, and the specific IFN-γ-secreting cells and IL-4-secreting cells were detected by ELISPOT assay u-sing ESAT-6 peptide as stimulus. Furthermore, CTL effects were in vivo evaluated by CFSE assay. Results The results showed that cellular immune responses specific for ESAT-6 could be detected by ELISPOT assay. In lung and PP cells, immune responses against ESAT-6 were biased toward Th1 type, the frequency of IFN-γ-secreting cells was much higher than that of IL-4-secreting cells. In splenocytes and MLN cells, the anti-gen specific immune responses acted as Thl and Th2 balance, the frequency of IFN-γ-secreting cells was close to that of IL-4-secreting cells. CFSE assay indicated that recombinant bacteria could induce the high level of CTL effects specific for ESAT-6 peptide. Conclusion These results suggested that recombinant Sal-monella typhimurium X4550(33-esat) not only can induce cellular immune responses, but also can elicit specific CTL responses after I. N immunization. It also provided the useful information for the control of infec-tious disease of tuberculosis.     

沙门氏菌鞭毛蛋白属共同抗原表位的鉴定

应用针对沙门氏菌鞭毛蛋一具有广谱反应性的单抗证实了该蛋白上存在共同抗原表位，进一步鉴定了鞭蛋白基因表达产物，结果同样表明该类共同抗原表位的存在。通过对该共同抗原表位在沙门氏菌属内外的分布规律测定，显示出它的属特异性。用单抗ＣＢＢ和display status     

应用PCR技术快速检测市售猪肉中产单核李斯特菌

目的：调查安徽省产单核李斯特菌对动物性食品的污染状况。方法：采集合肥农贸市场生猪肉样品，通过李斯特菌富集培养基培养16h，应用PCR技术进行产单核李斯特菌的检测。结果：从120份猪肉样品中分离出2株产单核李斯特菌，阳性检出率为1．7％。结论：表明安徽省市售猪肉中有不同程度产单核李斯特菌的污染，且存在李斯特菌病的可能性。整个检测过程只需24h，显示PCR技术对产单核李斯特菌的检测具有特异性强、灵敏度高、速度快和易操作等优点。