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.
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.
Ran XiaoShan LiQian CaoXiuling WangQiujin YanXiaoning TuYing ZhuFan Zhu
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.
The association between transcriptional activation of HERV and the develop- ment of schizophrenia was investigated. Nested RT-PCR was used to detect the preval- ence of HERV env RNA in the PBMCs of individuals with recent-onset of schizophrenia and normal persons from central and southern China. β-actin gene was used as an internal control. HERV env homologous sequences were found in the PBMCs of 8 of 28 (28.6%) individuals with recent-onset schizophrenia, while no env sequences were identified in any of the PBMCs obtained from 24 normal person (P<0.001). The results suggested that transcriptional activation of HERV might be associated with the develop- pment of schizophr- enia in at least some patients.
