抗鸡γ-干扰素单克隆抗体的研制及初步鉴定

目的:制备抗鸡γ-干扰素单克隆抗体(mAb)。方法:应用淋巴细胞杂交瘤技术,以重组菌BL21(DE3)(pET-ChIFN-γ)表达产物的包涵体作为抗原免疫BALB/c鼠,以纯化的GST-ChIFN-γ作为检测抗原,制备抗鸡γ-干扰素mAb;采用ELISA、Dot-ELISA和Westernblot鉴定mAb的特异性。结果:获得2株可稳定分泌抗鸡γ-干扰素mAb的杂交瘤细胞株1G5、5E3,其Ig亚类均为IgG2a,腹水mAb1G5、5E3的ELISA效价分别为1∶1600000,1∶120000。在Dot-ELISA试验中,这2株mAb均只与表达His-ChIFN-γ及GST-ChIFN-γ的重组大肠杆菌反应,与未表达这2种IFN-γ的其他8种菌株均不发生反应。在蛋白质印迹试验中,2株mAb均能与融合蛋白GST-ChIFN-γ、His-ChIFN-γ发生反应,出现特异性条带。结果表明,mAb1G5、5E3是针对鸡γ-干扰素的特异性mAb。结论:成功地制备抗鸡γ-干扰素的mAb,它们在免疫检测、免疫细胞功能分析和免疫调节研究等方面有应用价值。     

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.     

草分枝杆菌对SPCA/Ⅰ人肺腺癌细胞生长周期的影响以及促凋亡作用的研究

探讨草分子杆菌（Mycobacterium Phlei）对SPCA /Ⅰ人肺腺癌细胞系的调节细胞增殖周期及诱导细胞凋亡的作用。将SPCA /Ⅰ人肺腺癌细胞株培养传代,分别加入不同浓度的草分子杆菌,作用36小后,用倒置显微镜观察细胞形态,并以annexin V:FITC Apoptosis detection kit和cycletest plus DNA reagent kit标记,分别经FACSAria流式细胞仪检测细胞凋亡率和细胞周期改变。不同浓度的草分子杆菌体外对人肺腺癌细胞株SPCA /Ⅰ均有直接的抑制作用,其抑制率与所用药物浓度呈正相关;倒置显微镜下可见细胞由原来贴壁生长而逐渐脱落、外形变圆、体积缩小、折光性增强,核染色质凝集,细胞裂解。草分子杆菌体外能改变SPCA /Ⅰ人肺腺癌细胞株的细胞增殖周期,使细胞周期阻滞在G2-M期,对人肺腺癌细胞株SPCA /Ⅰ有诱导凋亡的作用,细胞凋亡率明显增加。草分子杆菌能通过调节细胞增殖周期和诱导细胞凋亡,直接抑制SPCA /Ⅰ人肺腺癌细胞株的增殖。     

紫草素诱导人绒毛膜癌JEG-3细胞凋亡机制的研究

背景与目的：研究紫草素（shikonin）诱导人绒毛膜癌JEG-3细胞的凋亡作用及其机制。材料与方法：采用四甲基偶氮唑盐（MTT）法测定紫草素对JEG-3细胞生长的抑制作用;Hoechst33258荧光染色和流式细胞术（FCM）检测紫草素处理JEG-3细胞后发生凋亡的形态变化;Western blot检测凋亡相关蛋白的活化。结果：MTT分析表明,紫草素抑制JEG-3细胞增殖,并呈时间和剂量依赖性（P〈0．01）,其半数有效抑制浓度（IC50）为（6．3±0．6）μmol／L;紫草素处理JEG-3细胞后,Hoechst33258染色出现典型的凋亡特征,且FCM检测出现明显的亚二倍体峰,Annexin V／P1双染出现早期凋亡细胞;Western blot检测结果显示经紫草素处理后JEG-3细胞的Caspase-3、ERK、JNK蛋白均被激活,而PARP蛋白被剪切成cleaved PARP（85KD）。结论：紫草素可能经Caspase-3途径诱导人绒毛膜癌细胞JEG-3凋亡,并且MAPK通路的活化、抑制对细胞的凋亡有一定的影响。     

人免疫球蛋白受体FcγRIIa的基因克隆及在K562细胞的表达

目的将外源人免疫球蛋白IgGFc段Ⅱ型受体CD32a分子表达于K562细胞表面,为构建人工抗原递呈细胞提供重要前提。方法自U937细胞RT-PCR得到CD32a的cDNA基因,与T载体连接后亚克隆入表达载体pcDNA3.1(+)。经测序后利用脂质体介导的转染将CD32a分子表达在K562细胞的表面。结果构建的T载体测序后,Genebank比对证实为CD32a的cDNA分子,免疫荧光和流式细胞仪结果均说明CD32a分子在K562细胞得到表达(96.9%)。结论获得的人工构建的表达人免疫球蛋白IgGFc受体的K562细胞,完成人工抗原递呈细胞制备的首要步骤。     

利用流式细胞仪检测人外周血NK细胞毒性方法的建立

目的利用流式细胞仪(FACS)技术检测人外周血NK细胞的毒性。方法首先将pEGFP-N1质粒转染人NK细胞的天然靶细胞K562,经过G418筛选后进一步单克隆化,得到稳定、均一表达绿色荧光蛋白的K562细胞。取对数期的K562-EGFP细胞与人外周血单个核细胞分别按5∶1、10∶1、20∶1、40∶1的比例混合,分别孵育0.5、1、2、4 h后用碘化丙啶(PI)标记,用流式细胞仪分析呈红、绿色荧光的细胞数,最后计算NK细胞的杀伤效率。结果0.5、1、2、4 h均能得到明显的杀伤效果,而且以2h的杀伤率最高。此时杀伤率与传统乳酸脱氢酶法(LDH)具有显著相关性(γ=0.997,P=0.003),而且显示出更强的敏感性。结论利用流式细胞仪检测NK细胞毒活性的方法可作为传统51Cr释放法、LDH法的一个补充,而且具有经济、快速和敏感的特点。     

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.     

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.