Membrane-associated RING-CH-1 (MARCH1) is an E3 ubiquitin ligase which targets MHC-II, CD86 and various other molecules for degradation. It is one of the most efficient post-translational regulators of antigen present...Membrane-associated RING-CH-1 (MARCH1) is an E3 ubiquitin ligase which targets MHC-II, CD86 and various other molecules for degradation. It is one of the most efficient post-translational regulators of antigen presentation. MARCH1 is expressed in resting immature dendritic cells and B cells but can be induced in other cell types. While activation of most immune cells results in a reduction in MARCH1 gene expression, its anti-inflammatory properties are highlighted by its induction in response to IL-10. Here, we review what is known about the regulation of MARCH1 gene expression in response to IL-10 by various immune cells. We speculate on the role of MARCH1 ininfection, its differential expression pattern and the promise that this E3 ubiquitin ligase holds to influence immune responses and mitigate immune pathologies.展开更多
目的:构建携带小鼠MHCII类分子反式激活因子(MHC class II molecule transactivator,CIITA)突变体基因的腺病毒,并观察腺病毒介导该基因的表达情况以及表达产物的体外功能。方法:采用常规分子生物学方法从IFN-γ诱导后的BALB/c小鼠腹腔...目的:构建携带小鼠MHCII类分子反式激活因子(MHC class II molecule transactivator,CIITA)突变体基因的腺病毒,并观察腺病毒介导该基因的表达情况以及表达产物的体外功能。方法:采用常规分子生物学方法从IFN-γ诱导后的BALB/c小鼠腹腔巨噬细胞中获得IV型CIITA cDNA;利用重叠延伸PCR法构建CIITA突变体基因,并克隆入表达载体pIRES;采用pAdEasy-1系统获得具有感染能力的、携带CIITA突变体基因的缺陷型重组腺病毒(Ad-CIITAm)和空载对照病毒(Ad-GFP),并经大量扩增、纯化及滴度测定;将Ad-CIITAm和Ad-GFP分别感染HeLa细胞和Raji细胞,流式细胞术观察对诱导型和组成型HLA-DR分子表达的影响。结果:成功克隆了小鼠CIITA突变体基因,并构建了携带小鼠CIITA突变体基因的重组腺病毒Ad-CIITAm;经流式细胞术证实感染Ad-CIITAm的Hela和Raji细胞较感染Ad-GFP的细胞,其表面HLA-DR分子的表达均受到明显的抑制。结论:本实验证实了重组腺病毒介导表达的小鼠CIITA突变体在体外能够有效地抑制MHCII类分子的表达。展开更多
评估IFN-γ调控型启动子(CIITA-pIV)驱动的MHC II类分子反式激活因子突变体(MHC class II transactivator mu-tant,CIITAm)重组腺病毒Ad-pIV-CIITAm对小鼠实验性自身免疫性甲状腺炎(experimental autoimmune thyroiditis,EAT)的治疗效果...评估IFN-γ调控型启动子(CIITA-pIV)驱动的MHC II类分子反式激活因子突变体(MHC class II transactivator mu-tant,CIITAm)重组腺病毒Ad-pIV-CIITAm对小鼠实验性自身免疫性甲状腺炎(experimental autoimmune thyroiditis,EAT)的治疗效果,并探讨其可能的作用机制。34只健康雌性CBA/J小鼠随机分成CIITAm治疗组(n=9)、GFP对照组(n=9)、EAT模型组(n=8)和正常对照组(n=8)共四组。正常对照组不做特殊处理,其余三组均以猪甲状腺球蛋白(porcinethyroglobulin,pTg)+弗氏佐剂(complete or incomplete Freund adjuvant,CFA/IFA)建立EAT小鼠模型,并分别静脉注射重组腺病毒Ad-pIV-CIITAm、Ad-GFP及等体积生理盐水。首次免疫后第29天处死小鼠,进行H-E染色观察甲状腺病理形态;免疫组织化学染色测定甲状腺MHC II类分子表达;分析pTg刺激下脾脏淋巴细胞的增殖及其上清液中IFN-γ的分泌水平;ELISA法检测血浆中抗-pTg自身抗体滴度;流式细胞术分析外周血和脾脏淋巴细胞中T细胞亚群。结果:H-E染色结果表明,CIITAm治疗组甲状腺淋巴细胞浸润指数(0.5±0.5)低于GFP对照组(1.5±0.2)和EAT模型组(1.4±0.4,P<0.01)。免疫组化结果显示,GFP对照组和EAT模型组甲状腺组织有弥漫性MHC II类分子表达,而CIITAm治疗组未见明显表达,正常对照组表达呈阴性。80μg/ml pTg刺激下,CIITAm治疗组小鼠淋巴细胞刺激指数(SI)明显低于GFP对照组或EAT模型组(P<0.01);培养上清各组IFN-γ分泌水平结果类似(P<0.01)。CIITAm治疗组血浆抗-pTg自身抗体滴度显著低于GFP对照组或EAT模型组(P<0.05);CIITAm治疗组外周血和脾脏CD4+T细胞百分率亦显著低于GFP对照组或EAT模型组(P<0.05)。重组腺病毒Ad-pIV-CIITAm能抑制EAT小鼠甲状腺组织MHC II类分子表达,抑制自身反应性T细胞增殖,减轻甲状腺炎性细胞浸润,降低自身抗体滴度,对EAT有一定的治疗作用。展开更多
文摘Membrane-associated RING-CH-1 (MARCH1) is an E3 ubiquitin ligase which targets MHC-II, CD86 and various other molecules for degradation. It is one of the most efficient post-translational regulators of antigen presentation. MARCH1 is expressed in resting immature dendritic cells and B cells but can be induced in other cell types. While activation of most immune cells results in a reduction in MARCH1 gene expression, its anti-inflammatory properties are highlighted by its induction in response to IL-10. Here, we review what is known about the regulation of MARCH1 gene expression in response to IL-10 by various immune cells. We speculate on the role of MARCH1 ininfection, its differential expression pattern and the promise that this E3 ubiquitin ligase holds to influence immune responses and mitigate immune pathologies.
文摘目的:构建携带小鼠MHCII类分子反式激活因子(MHC class II molecule transactivator,CIITA)突变体基因的腺病毒,并观察腺病毒介导该基因的表达情况以及表达产物的体外功能。方法:采用常规分子生物学方法从IFN-γ诱导后的BALB/c小鼠腹腔巨噬细胞中获得IV型CIITA cDNA;利用重叠延伸PCR法构建CIITA突变体基因,并克隆入表达载体pIRES;采用pAdEasy-1系统获得具有感染能力的、携带CIITA突变体基因的缺陷型重组腺病毒(Ad-CIITAm)和空载对照病毒(Ad-GFP),并经大量扩增、纯化及滴度测定;将Ad-CIITAm和Ad-GFP分别感染HeLa细胞和Raji细胞,流式细胞术观察对诱导型和组成型HLA-DR分子表达的影响。结果:成功克隆了小鼠CIITA突变体基因,并构建了携带小鼠CIITA突变体基因的重组腺病毒Ad-CIITAm;经流式细胞术证实感染Ad-CIITAm的Hela和Raji细胞较感染Ad-GFP的细胞,其表面HLA-DR分子的表达均受到明显的抑制。结论:本实验证实了重组腺病毒介导表达的小鼠CIITA突变体在体外能够有效地抑制MHCII类分子的表达。