为比较禽类恒定链的结构和功能,应用RACE(Rapid Amplification of cDNA Ends)技术首次克隆并鉴定了鸽恒定链基因。首先用一对含高度保守的DNA片段的简并引物,从鸽脾细胞RNA扩增部分恒定链片段,接着测序并设计新引物分别从5′和3′RACE...为比较禽类恒定链的结构和功能,应用RACE(Rapid Amplification of cDNA Ends)技术首次克隆并鉴定了鸽恒定链基因。首先用一对含高度保守的DNA片段的简并引物,从鸽脾细胞RNA扩增部分恒定链片段,接着测序并设计新引物分别从5′和3′RACE扩增延长该片段。最后根据全基因的序列设计上、下游引物,获得大小为1050bp的全长cDNA。比较核苷酸序列,鸽与鸡的Ii链同源性达到82.8%,而与人等其它动物的同源性则在52.0%以上;其中633bp的开放阅读框编码211个氨基酸残基的前体蛋白。推导和分析氨基酸序列表明,分子结构与鸡恒定链相似,其中有些氨基酸残基表现出较高的保守性。展开更多
Background Genetic modification of dendritic cells （DCs） has been used as an effective approach to enhance anti-tumor immunity. RNA interference （RNAi）, which can cause the degradation of any RNA in a sequence-spe...Background Genetic modification of dendritic cells （DCs） has been used as an effective approach to enhance anti-tumor immunity. RNA interference （RNAi）, which can cause the degradation of any RNA in a sequence-specific manner, is a post-transcriptional gene silencing mechanism. In this study, small-interfering RNA （siRNA） specific for the li gene was transfected into DCs, and the anti-tumor immunity of li-silenced DCs was assessed. Methods The silencing effect of siRNA was evaluated by Western blotting and real-time PCR analyses. In vitro cytotoxic activity of T cells was evaluated using a Cytotox 96 non-radioactive cytotoxicity assay kit. The time to tumor onset and the tumor volumes were used as reliable indices to assess the anti-tumor immunity in vivo. To further examine the mechanisms underlying the anti-tumor immunity, flow cytometry analysis was used. Results The li expression of DCs was significantly reduced after li siRNA transfection. Significant in vitro anti-tumor ability was exhibited when DCs were co-transfected with li siRNA plus endogenous tumor antigen （P 〈0.05）. Furthermore tumor growth was greatly inhibited when mice were immunized with DCs transfected with li siRNA plus tumor antigen prior to or subsequent to tumor implantation. Flow cytometry analysis in vitro and in vivo indicated that both CD4^= and CD8^＋ T cells were significantly activated in the li siRNA group （P 〈0.05）. Conclusion Silencing of the li gene of DCs may offer a potential approach to enhance DC-based anti-tumor immunity.展开更多
目的构建粉尘螨变应原ProDerf1原核表达载体pET28a-YARA—IhC—ProDerf1,为评价其免疫治疗效果奠定基础。方法用分子克隆技术构建出表达载体pET28a—YARA—IhC—ProDerf1,在E.coli BL21(DE3)中表达融合蛋白YARA-IhC-ProDer f 1,并进行Ni...目的构建粉尘螨变应原ProDerf1原核表达载体pET28a-YARA—IhC—ProDerf1,为评价其免疫治疗效果奠定基础。方法用分子克隆技术构建出表达载体pET28a—YARA—IhC—ProDerf1,在E.coli BL21(DE3)中表达融合蛋白YARA-IhC-ProDer f 1,并进行Ni^(2+)-NTA树脂柱亲和层析以纯化蛋白。结果经测序证实成功构建了表达载体pET28a-YARA-IhC-ProDer f 1,YARA-IhC-ProDer f 1融合蛋白在E.coli BL21(DE3)中得到表达,纯化后的蛋白浓度为278μg/ml。SDS-PAGE和Westem blot分析表明纯化蛋白为目的蛋白YARA-IhC-ProDer f 1。结论已成功制备出pET28a—YARA—IhC-ProD—er f 1原核表达载体,融合蛋白得到表达和纯化。展开更多
文摘为比较禽类恒定链的结构和功能,应用RACE(Rapid Amplification of cDNA Ends)技术首次克隆并鉴定了鸽恒定链基因。首先用一对含高度保守的DNA片段的简并引物,从鸽脾细胞RNA扩增部分恒定链片段,接着测序并设计新引物分别从5′和3′RACE扩增延长该片段。最后根据全基因的序列设计上、下游引物,获得大小为1050bp的全长cDNA。比较核苷酸序列,鸽与鸡的Ii链同源性达到82.8%,而与人等其它动物的同源性则在52.0%以上;其中633bp的开放阅读框编码211个氨基酸残基的前体蛋白。推导和分析氨基酸序列表明,分子结构与鸡恒定链相似,其中有些氨基酸残基表现出较高的保守性。
基金This research was supported by grants from the National Natural Science Foundation of China （No. 30570828 and No. 30471961）.Acknowledgements： The authors deeply appreciate technical assistance from Q. Li and D. Q. Zhang valuble discussion with R. F Ge and help from the experimental Animal Facility technicians for animal care. We thank the International Science Editing for help in editing our manuscript.
文摘Background Genetic modification of dendritic cells （DCs） has been used as an effective approach to enhance anti-tumor immunity. RNA interference （RNAi）, which can cause the degradation of any RNA in a sequence-specific manner, is a post-transcriptional gene silencing mechanism. In this study, small-interfering RNA （siRNA） specific for the li gene was transfected into DCs, and the anti-tumor immunity of li-silenced DCs was assessed. Methods The silencing effect of siRNA was evaluated by Western blotting and real-time PCR analyses. In vitro cytotoxic activity of T cells was evaluated using a Cytotox 96 non-radioactive cytotoxicity assay kit. The time to tumor onset and the tumor volumes were used as reliable indices to assess the anti-tumor immunity in vivo. To further examine the mechanisms underlying the anti-tumor immunity, flow cytometry analysis was used. Results The li expression of DCs was significantly reduced after li siRNA transfection. Significant in vitro anti-tumor ability was exhibited when DCs were co-transfected with li siRNA plus endogenous tumor antigen （P 〈0.05）. Furthermore tumor growth was greatly inhibited when mice were immunized with DCs transfected with li siRNA plus tumor antigen prior to or subsequent to tumor implantation. Flow cytometry analysis in vitro and in vivo indicated that both CD4^= and CD8^＋ T cells were significantly activated in the li siRNA group （P 〈0.05）. Conclusion Silencing of the li gene of DCs may offer a potential approach to enhance DC-based anti-tumor immunity.
文摘目的构建粉尘螨变应原ProDerf1原核表达载体pET28a-YARA—IhC—ProDerf1,为评价其免疫治疗效果奠定基础。方法用分子克隆技术构建出表达载体pET28a—YARA—IhC—ProDerf1,在E.coli BL21(DE3)中表达融合蛋白YARA-IhC-ProDer f 1,并进行Ni^(2+)-NTA树脂柱亲和层析以纯化蛋白。结果经测序证实成功构建了表达载体pET28a-YARA-IhC-ProDer f 1,YARA-IhC-ProDer f 1融合蛋白在E.coli BL21(DE3)中得到表达,纯化后的蛋白浓度为278μg/ml。SDS-PAGE和Westem blot分析表明纯化蛋白为目的蛋白YARA-IhC-ProDer f 1。结论已成功制备出pET28a—YARA—IhC-ProD—er f 1原核表达载体,融合蛋白得到表达和纯化。
