PERV的整合对HEK293细胞中HERV-W mRNA表达的影响

目的明确PERV的整合是否影响HEK293细胞中HERV-W各基因表达水平。方法根据GenBank中登录的基因序列,分别设计HERV-W gag、HERV-W pol、HERV-Wenv、syncytin-1和humanβ-actin引物,并分别建立SYBR Green Ⅰ荧光定量PCR检测方法,用于检测HEK293、HEK293-PERV中各基因mRNA的表达。结果本研究建立的检测方法均具有良好的特异性、敏感性和稳定性,标准曲线的相关系数大于0.99,扩增效率介于95%~110%,可用于检测。结论检测结果经2^(-△△Ct)分析后,发现与对照相比,PERV整合后的HEK293-PERV中HERV-Wgag、HERV-Wpol、HERV-Wenv和syncytin-1 mRNA相对表达量分别升高37.08倍、42.56倍、2.49倍和13.17倍,为进一步明确PERV在异种移植中的安全性提供参考。

Domesticated HERV-W env contributes to the activation of the small conductance Ca^(2+)-activated K^(+)type 2 channels via decreased 5-HT4 receptor in recent-onset schizophrenia

The human endogenous retroviruses type W family envelope(HERV-W env)gene is located on chromosome 7q21-22.Our previous studies show that HERV-W env is elevated in schizophrenia and HERV-W env can increase cal-cium influx.Additionally,the 5-HTergie system and particularly 5-hydroxytryptamine(5-HT)receptors play a prominent role in the pathogenesis and treatment of schizophrenia.5-hydroxytryptamine receptor 4(5-HT4R)agonist can block calcium channels.However,the underlying relationship between HERV-W env and 5-HT4R in the etiology of schizophrenia has not been revealed.Here,we used enzyme-linked immunosorbent assay to detect the concentration of HERV-W env and 5-HT4R in the plasma of patients with schizophrenia and we found that there were decreased levels of 5-HT4R and a negative correlation between 5-HT4R and HERV-W env in schizophrenia.Overexpression of HERV-W env decreased the transcription and protein levels of 5-HT4R but increased small conductance Ca^(2+)-activated K^(+)type 2 channels(SK2)expression levels.Further studies revealed that HERV-w env could interact with 5-HT4R.Additionally,luciferase assay showed that an essential region(-364 to-176 from the transcription start site)in the SK2 promoter was required for HERV-W env-induced SK2 expression.Importantly,5-HT4R participated in the regulation of SK2 expression and promoter activity.Electrophysiological recordings suggested that HERV-Wenv could increase SK2 channel currents and the increase of SK2 currents was inhibited by 5-HT4R.In condusion,HERV-W env could activate SK2 channels via decreased 5-HT4R,which might exhibit a novel mechanism for HERV-Wenv to influence neuronal activity in schizophrenia.

广西巴马小型猪内源性反转录病毒整合后传代次数对HEK293细胞中HERV-W表达和变异的影响

检测不同代次广西巴马小型猪内源性反转录病毒(PERV)感染HEK293细胞模型(HEK293-PERV-BM)中,HERV-W各基因mRNA和syncytin-1蛋白表达水平,以及HERV-W各基因变异情况,评价PERV的整合对HERV-W的影响。结果显示,与HEK293细胞相比,PERV整合后,不同代次HEK293-PERV-BM中HERV-W gag、pol、env和syncytin-1的mRNA相对表达量出现不同程度的改变,且改变趋势相似,即P10或P20后开始升高,至P30最高;选取相对表达量差别较大代次,检测其syncytin-1蛋白,各代次间syncytin-1蛋白表达量的改变较mRNA的差别小。此外,PERV整合后,在P1~P55中HERV-W结构基因仅发生个别位置的点突变,未见发生固定位置的点突变或基因片段的缺失、插入及重组。本试验为系统评价PERV-BM在异种器官移植中的安全性提供参考。

Human leukemia antigen-A0201-restricted epitopes of humanendogenous retrovirus W family envelope(HERV-W env)inducestrong cytotoxic T lymphocyte responses

Human endogenous retrovirus W family(HERV-W) envelope(env) has been reported to be related to several human diseases, including autoimmune disorders, and it could activate innate immunity.However, there are no reports investigating whether human leukemia antigen(HLA)-A~*0201^+restriction is involved in the immune response caused by HERV-W env in neuropsychiatric diseases. In the present study, HERV-W env-derived epitopes presented by HLA-A~*0201 are described with the potential for use in adoptive immunotherapy. Five peptides displaying HLAA~*0201-binding motifs were predicted using SYFEPITHI and BIMAS, and synthesized. A CCK-8 assay showed peptides W, Q and T promoted lymphocyte proliferation. Stimulation of peripheral blood mononuclear cells from HLA-A~*0201^+ donors with each of these peptides induced peptidespecific CD8^+ T cells. High numbers of IFN-γ-secreting T cells were also detectable after several weekly stimulations with W, Q and T. Besides lysis of HERV-W env-loaded target cells, specific apoptosis was also observed. These data demonstrate that human T cells can be sensitized toward HERV-W env peptides(W, Q and T) and, moreover, pose a high killing potential toward HERV-W env-expressing U251 cells. In conclusion, peptides W Q and T, which are HERV-W env antigenic epitopes, have both antigenicity and immunogenicity, and can cause strong T cell immune responses. Our data strengthen the view that HERV-W env should be considered as an autoantigen that can induce autoimmunity in neuropsychiatric diseases, such as multiple sclerosis and schizophrenia. These data might provide an experimental foundation for a HERV-W env peptide vaccine and new insight into the treatment of neuropsychiatric diseases.

人内源性逆转录病毒W家族与疾病相关性的研究

人内源性逆转录病毒(human endogenous retroviruses,HERV)是几百万年前整合至人类基因组并遗传至今的外源性逆转录病毒的残余物。因突变、缺失等导致大多数HERV没有完整的开放读码框,但仍有部分家族成员可编码完整的病毒蛋白,如分离自多发性硬化症患者的γ逆转录病毒相似元件家族成员HERV-W的包膜蛋白基因(HERV-W env,又称ERVWE1)编码的ENV蛋白(又称Syncytin-1),在人胎盘发育过程中起细胞融合以及免疫调节作用。在生理条件下,HERV-W受到表观遗传调控而其转录活性被抑制;但亦可被环境、遗传等因素激活,如自身免疫性疾病、精神疾病及癌症等。研究发现HERV-W可能在疾病的发生、发展中起重要的“桥梁”与“触发”作用,靶向Syncytin-1的单克隆抗体GNbAC1已用于多发性硬化症的临床研究,并且在1型糖尿病中也有良好的应用前景。对HERV-W的深入研究可为某些疾病的诊断和治疗提供重要的途径。

有关精神分裂症的新发现

利用逆转录病毒分子印记法,通过对精神分裂症患者的脑脊液进行检测,为部分精神分裂症可能与某种病毒有关提供了证据。霍普金斯儿童中心的研究人员的有关研究报告刊登在近期的《美国国家科学杂志》上。利用分子标记技术,

Human Endogenous Retrovirus Type W Envelope from Multiple Sclerosis Demyelinating Lesions Shows Unique Solubility and Antigenic Characteristics

In multiple sclerosis(MS),human endogenous retrovirus W family(HERV-W)envelope protein,pHERV-W ENV,limits remyelination and induces microglia-mediated neurodegeneration.To better understand its role,we examined the soluble pHERV-W antigen from MS brain lesions detected by specific antibodies.Physico-chemical and antigenic characteristics confirmed differences between pHERV-W ENV and syncytin-1.pHERV-W ENV monomers and trimers remained associated with membranes,while hexamers self-assembled from monomers into a soluble macrostructure involving sulfatides in MS brain.Extracellular hexamers are stabilized by internal hydrophobic bonds and external hydrophilic moieties.HERV-W studies in MS also suggest that this diffusible antigen may correspond to a previously described highmolecular-weight neurotoxic factor secreted by MS B-cells and thus represents a major agonist in MS pathogenesis.Adapted methods are now needed to identify encoding HERV provirus(es)in affected cells DNA.The properties and origin of MS brain pHERV-W ENV soluble antigen will allow a better understanding of the role of HERVs in MS pathogenesis.The present results anyhow pave the way to an accurate detection of the different forms of pHERV-W ENV antigen with appropriate conditions that remained unseen until now.

Human endogenous retrovirus W env increases nitric oxide production and enhances the migration ability of microglia by regulating the expression of inducible nitric oxide synthase

Human endogenous retrovirus W env(HERV-W env) plays a critical role in many neuropsychological diseases such as schizophrenia and multiple sclerosis(MS). These diseases are accompanied by immunological reactions in the central nervous system(CNS). Microglia are important immunocytes in brain inflammation that can produce a gasotransmitter – nitric oxide(NO). NO not only plays a role in the function of neuronal cells but also participates in the pathogenesis of various neuropsychological diseases. In this study, we reported increased NO production in CHME-5 microglia cells after they were transfected with HERV-W env. Moreover, HERV-W env increased the expression and function of human inducible nitric oxide synthase(hi NOS) and enhanced the promoter activity of hi NOS. Microglial migration was also enhanced. These data revealed that HERV-W env might contribute to increase NO production and microglial migration ability in neuropsychological disorders by regulating the expression of inducible NOS. Results from this study might lead to the identification of novel targets for the treatment of neuropsychological diseases, including neuroinflammatory diseases, stroke, and neurodegenerative diseases.