The worldwide declines in amphibian populations have largely been caused by infectious fungi and bacteria. Given that vertebrate immunity against these extracellular pathogens is primarily functioned by the major hist...The worldwide declines in amphibian populations have largely been caused by infectious fungi and bacteria. Given that vertebrate immunity against these extracellular pathogens is primarily functioned by the major histocompatibility complex（MHC） class Ⅱ molecules, the characterization and the evolution of amphibian MHC class Ⅱ genes have attracted increasing attention. The polymorphism of MHC class Ⅱ genes was found to be correlated with susceptibility to fungal pathogens in many amphibian species, suggesting the importance of studies on MHC class Ⅱ genes for amphibians. However, such studies on MHC class Ⅱ gene evolution have rarely been conducted on amphibians in China. In this study, we chose Omei treefrog（Rhacophorus omeimontis）, which lived moist environments easy for breeding bacteria, to study the polymorphism of its MHC class Ⅱ genes and the underlying evolutionary mechanisms. We amplified the entire MHC class ⅡB exon 2 sequence in the R. omeimontis using newly designed primers. We detected 102 putative alleles in 146 individuals. The number of alleles per individual ranged from one to seven, indicating that there are at least four loci containing MHC class ⅡB genes in R. omeimontis. The allelic polymorphism estimated from the 102 alleles in R. omeimontis was not high compared to that estimated in other anuran species. No significant gene recombination was detected in the 102 MHC class ⅡB exon 2 sequences. In contrast, both gene duplication and balancing selection greatly contributed to the variability in MHC class ⅡB exon 2 sequences of R. omeimontis. This study lays the groundwork for the future researches to comprehensively analyze the evolution of amphibian MHC genes and to assess the role of MHC gene polymorphisms in resistance against extracellular pathogens for amphibians in China.展开更多
为进一步丰富鱼类MHC class Ⅱ基因的研究,同时也为进一步探讨低磷饲料中添加维生素D3对鱼类免疫功能可能的影响,实验利用RACE(Rapid-amplification of c DNA ends)即c DNA末端快速扩增技术,成功克隆出黄颡鱼(Pelteobagrus fulvidraco)...为进一步丰富鱼类MHC class Ⅱ基因的研究,同时也为进一步探讨低磷饲料中添加维生素D3对鱼类免疫功能可能的影响,实验利用RACE(Rapid-amplification of c DNA ends)即c DNA末端快速扩增技术,成功克隆出黄颡鱼(Pelteobagrus fulvidraco)主要组织相容性复合体(Major histocompatibility complex,MHC)class Ⅱ抗原基因,全长1074 bp,其中ORF(Open reading frame)708 bp,编码236个氨基酸,5′UTR(5′端非翻译区)78 bp,3′UTR(3′端非翻译区)259 bp。进行氨基酸序列比对分析得到:黄颡鱼MHC class Ⅱ基因ORF氨基酸序列与长吻逘(Leiocassis longirostris)的氨基酸序列相似度最高为69.5%,与锦鲤(Cyprinus carpio)的氨基酸序列相似度最低为50.4%。利用q PCR对黄颡鱼MHC class Ⅱ基因进行组织表达分析,结果表明MHC class Ⅱ在小肠、肝脏、鳃中表达较高;在肌肉、鳍条中表达较低;而在肾、脾脏、脑、头肾中表达量极低(几乎检测不到)。在低磷饲料中添加维生素D3显著诱导了该基因的上调表达。研究结果展示了黄颡鱼MHC class Ⅱ抗原基因的分子结构、组织表达以及维生素D3的作用,在降低磷排放的同时,为今后黄颡鱼免疫抗病及分子选育等方向的深入研究及免疫型饲料的使用奠定了基础。展开更多
目的:探讨MHC-Ⅰ类相关链基因A(MHC class-Ⅰchain related gene A,MICA)与湖南地区白血病之间的相关性。方法:应用荧光聚合酶链反应-基因扫描技术和聚合酶链反应-序列特异性引物技术分析,对62例白血病患者和112名正常人群进行MICA基因...目的:探讨MHC-Ⅰ类相关链基因A(MHC class-Ⅰchain related gene A,MICA)与湖南地区白血病之间的相关性。方法:应用荧光聚合酶链反应-基因扫描技术和聚合酶链反应-序列特异性引物技术分析,对62例白血病患者和112名正常人群进行MICA基因第5外显子微卫星等位基因分型及MICA基因缺失检测。结果:慢性粒细胞白血病组(n=35)的MICA*A5基因频率显著低于正常对照组(RR=0.635,P=0.0380);急性淋巴细胞性白血病组(n=13)的MICA*A4基因频率显著低于正常对照组(RR=0.120,P=0.0297);而在急性非淋巴细胞性白血病组(n=14),MICA*A5基因频率显著高于正常对照组(RR=2.229,P=0.0218)。结论:本文数据显示,MICA-STR多态性与湖南地区白血病之间存在相关性;不同病理类型的白血病相关格局有所不同。展开更多
This word was supported by grant from Military Medical Research Foundation of china (96z032). ** To whom correspondence and requests for reprints should be addressed. This is one of papers of the special ...This word was supported by grant from Military Medical Research Foundation of china (96z032). ** To whom correspondence and requests for reprints should be addressed. This is one of papers of the special issue on gene therapy research (Chin J Cancer Res Vol. 9 No. 4 December, 1997). In order to investigate the antitumor effects of the in vivo G CSF gene therapy mediated by liposome and its mechanisms, human G CSF gene was encapsulated into liposome and was directly injected into tumor mass of C 26 colon adenocarcinoma bearing mice. After direct intratumoral injection of liposome encapsulated G CSF DNA, the subcutaneous tumor growth was dramatically inhibited and the survival time was prolonged signifi cantly. Tumor regression could be observed in about 30% of C 26 bearing mice. By the analysis of the antitumor mechanisms, we found that anti G 418 (600ug/ml) clone could be selected from the tumor cells freshly separated from the treated C 26 tumor mass, and secretion of G CSF in the supernatant could be detected. Northern blot also confirmed the expression of hG CSF by the tumor cells. Higher expressions of MHC class I(H 2k d) molecule and ICAM 1 on the tumor cells could be observed. The results demonstrated that liposome can effectively transfect G CSF gene into tumor cells in situ , and then increase the immunogenicity of the tumor cells which may contribute to the activation of the local antitumor immune responses effectively.展开更多
基金supported by the National Natural Science Foundation of China(No.31201713,No.31270425 and No.31470442)
文摘The worldwide declines in amphibian populations have largely been caused by infectious fungi and bacteria. Given that vertebrate immunity against these extracellular pathogens is primarily functioned by the major histocompatibility complex（MHC） class Ⅱ molecules, the characterization and the evolution of amphibian MHC class Ⅱ genes have attracted increasing attention. The polymorphism of MHC class Ⅱ genes was found to be correlated with susceptibility to fungal pathogens in many amphibian species, suggesting the importance of studies on MHC class Ⅱ genes for amphibians. However, such studies on MHC class Ⅱ gene evolution have rarely been conducted on amphibians in China. In this study, we chose Omei treefrog（Rhacophorus omeimontis）, which lived moist environments easy for breeding bacteria, to study the polymorphism of its MHC class Ⅱ genes and the underlying evolutionary mechanisms. We amplified the entire MHC class ⅡB exon 2 sequence in the R. omeimontis using newly designed primers. We detected 102 putative alleles in 146 individuals. The number of alleles per individual ranged from one to seven, indicating that there are at least four loci containing MHC class ⅡB genes in R. omeimontis. The allelic polymorphism estimated from the 102 alleles in R. omeimontis was not high compared to that estimated in other anuran species. No significant gene recombination was detected in the 102 MHC class ⅡB exon 2 sequences. In contrast, both gene duplication and balancing selection greatly contributed to the variability in MHC class ⅡB exon 2 sequences of R. omeimontis. This study lays the groundwork for the future researches to comprehensively analyze the evolution of amphibian MHC genes and to assess the role of MHC gene polymorphisms in resistance against extracellular pathogens for amphibians in China.
文摘为进一步丰富鱼类MHC class Ⅱ基因的研究,同时也为进一步探讨低磷饲料中添加维生素D3对鱼类免疫功能可能的影响,实验利用RACE(Rapid-amplification of c DNA ends)即c DNA末端快速扩增技术,成功克隆出黄颡鱼(Pelteobagrus fulvidraco)主要组织相容性复合体(Major histocompatibility complex,MHC)class Ⅱ抗原基因,全长1074 bp,其中ORF(Open reading frame)708 bp,编码236个氨基酸,5′UTR(5′端非翻译区)78 bp,3′UTR(3′端非翻译区)259 bp。进行氨基酸序列比对分析得到:黄颡鱼MHC class Ⅱ基因ORF氨基酸序列与长吻逘(Leiocassis longirostris)的氨基酸序列相似度最高为69.5%,与锦鲤(Cyprinus carpio)的氨基酸序列相似度最低为50.4%。利用q PCR对黄颡鱼MHC class Ⅱ基因进行组织表达分析,结果表明MHC class Ⅱ在小肠、肝脏、鳃中表达较高;在肌肉、鳍条中表达较低;而在肾、脾脏、脑、头肾中表达量极低(几乎检测不到)。在低磷饲料中添加维生素D3显著诱导了该基因的上调表达。研究结果展示了黄颡鱼MHC class Ⅱ抗原基因的分子结构、组织表达以及维生素D3的作用,在降低磷排放的同时,为今后黄颡鱼免疫抗病及分子选育等方向的深入研究及免疫型饲料的使用奠定了基础。
文摘目的:探讨MHC-Ⅰ类相关链基因A(MHC class-Ⅰchain related gene A,MICA)与湖南地区白血病之间的相关性。方法:应用荧光聚合酶链反应-基因扫描技术和聚合酶链反应-序列特异性引物技术分析,对62例白血病患者和112名正常人群进行MICA基因第5外显子微卫星等位基因分型及MICA基因缺失检测。结果:慢性粒细胞白血病组(n=35)的MICA*A5基因频率显著低于正常对照组(RR=0.635,P=0.0380);急性淋巴细胞性白血病组(n=13)的MICA*A4基因频率显著低于正常对照组(RR=0.120,P=0.0297);而在急性非淋巴细胞性白血病组(n=14),MICA*A5基因频率显著高于正常对照组(RR=2.229,P=0.0218)。结论:本文数据显示,MICA-STR多态性与湖南地区白血病之间存在相关性;不同病理类型的白血病相关格局有所不同。
文摘This word was supported by grant from Military Medical Research Foundation of china (96z032). ** To whom correspondence and requests for reprints should be addressed. This is one of papers of the special issue on gene therapy research (Chin J Cancer Res Vol. 9 No. 4 December, 1997). In order to investigate the antitumor effects of the in vivo G CSF gene therapy mediated by liposome and its mechanisms, human G CSF gene was encapsulated into liposome and was directly injected into tumor mass of C 26 colon adenocarcinoma bearing mice. After direct intratumoral injection of liposome encapsulated G CSF DNA, the subcutaneous tumor growth was dramatically inhibited and the survival time was prolonged signifi cantly. Tumor regression could be observed in about 30% of C 26 bearing mice. By the analysis of the antitumor mechanisms, we found that anti G 418 (600ug/ml) clone could be selected from the tumor cells freshly separated from the treated C 26 tumor mass, and secretion of G CSF in the supernatant could be detected. Northern blot also confirmed the expression of hG CSF by the tumor cells. Higher expressions of MHC class I(H 2k d) molecule and ICAM 1 on the tumor cells could be observed. The results demonstrated that liposome can effectively transfect G CSF gene into tumor cells in situ , and then increase the immunogenicity of the tumor cells which may contribute to the activation of the local antitumor immune responses effectively.
