HIV-1附属蛋白特异性细胞毒性T细胞（CTL）应答研究

发布时间：2018-05-19 03:12

  本文选题：人类免疫缺陷病毒-1 + 艾滋病　； 参考：《第四军医大学》2007年硕士论文

【摘要】： 获得性免疫缺陷综合征(AIDS)已经夺取了近四千万人的生命并严重威胁着人类健康。高效抗逆转录病毒疗法虽然在抑制HIV-1复制、免疫重建、降低AIDS相关疾病的发病率及延长HIV感染后发病时间上有良好的效果。然而由于这些抗病毒药物价格昂贵、毒副作用大、HIV-1耐药株的产生以及患者依从性不好影响了抗病毒治疗的疗效。因此安全有效的疫苗来控制HIV-1的流行和传播将成为人类战胜HIV的重要武器。 特异性的细胞毒性T细胞(CTL)应答在控制HIV-1和SIV复制中发挥重要作用。诱导机体产生针对HIV-1强烈的CTL应答成为目前HIV-1疫苗研制的热点。Nef蛋白是HIV感染早期表达的蛋白质之一,同时也是HIV-1感染后CTL最早识别并产生应答的靶蛋白。现已证实其能够通过激活CD4淋巴细胞,提高病毒颗粒的感染性,增加CD4分子和MHC分子的内吞,以及防止受感染细胞凋亡等多种途径对HIV的复制起到重要的促进作用。Vpu通过影响新合成CD4分子向细胞膜转运和增加CD4分子从细胞膜向细胞内内吞来下调细胞表面的CD4。Vpr蛋白通过促进整合前复合物(PIC)从胞浆到胞核的转运对病毒感染静止期的细胞起到了重要作用。Vpr还可以使宿主细胞的细胞周期在G2/M期滞留,结果容易引起的细胞凋亡,甚至引起分裂细胞凋亡。Vif可以通过抑制抗病毒因子APOBEC3G的活性,增强病毒的感染性。Vif也可以使细胞周期滞留在G2/M期。 本研究选取61例HIV-1感染者/AIDS患者和10例HIV抗体阴性的健康对照者作为研究对象。进行CD4细胞计数、病毒载量检测并收集一般的临床资料。应用覆盖HIV-1B、C亚型附属蛋白(Nef、Vpu、Vpr和Vif)的142个肽段作为抗原,刺激来自研究对象的CTL产生γ-干扰素,采用酶联免疫斑点吸附试验(ELISpot)检测,来定量测定HIV-1附属蛋白特异性CD8+T细胞应答,对中国人群HIV-1附属蛋白特异性CD8+T细胞应答反应进行了较全面的研究。 本研究发现无论对HIV-1B亚型还是HIV-1C亚型附属蛋白都能产生特异性CTL应答,特别是Nef区蛋白的反应频率和累积应答强度都较高(P0.001),B、C亚型间的应答频率和累积应答强度都无显著差别(P0.05),其免疫优势区也大致相同,并筛选出了附属蛋白区的免疫优势区。附属蛋白特异性的累积CTL应答强度将近达到总应答的21%。这些结果表明尽管HIV-1附属蛋白的序列较短,但它们在诱导特异性的CTL应答中发挥了重要作用。 总之,本课题初步研究了HIV-1附属蛋白特异性的CTL应答特征,评价了HIV-1附属蛋白特异性的CTL应答在HIV-1激发的CTL应答中的地位,确定了HIV-1附属蛋白区内CD8+T细胞应答的优势区域。为进一步筛选CTL表位和制备安全、有效的HIV-1疫苗奠定了基础。
[Abstract]:High effective antiretroviral therapy has a good effect on inhibiting HIV-1 replication, immune reconstruction, reducing the incidence of AIDS related diseases and prolonging the onset time of HIV infection. However, because of the high cost of these antiviral drugs, the production of HIV-1 resistant strains and the poor compliance of patients have affected the efficacy of antiviral therapy. Therefore, a safe and effective vaccine to control the prevalence and spread of HIV-1 will become an important weapon for human to defeat HIV. Specific cytotoxic T lymphocyte (CTL) responses play an important role in controlling HIV-1 and SIV replication. Inducing a strong CTL response to HIV-1 has become a hot spot in the development of HIV-1 vaccine. Nef protein is one of the proteins expressed in the early stage of HIV infection, and it is also the first target protein to recognize and produce the response of CTL after HIV-1 infection. It has been proved that it can increase the infectivity of virus particles and endocytosis of CD4 molecules and MHC molecules by activating CD4 lymphocytes. Vpu plays an important role in promoting the replication of HIV by affecting the transport of newly synthesized CD4 molecules to the cell membrane and increasing the CD4 molecule from cell membrane to endocytosis to down-regulate the cell surface. VPR protein plays an important role in the cytosolic transport from cytoplasm to nucleus by promoting the transport of preintegrative complex. VPR can also make the cell cycle of host cells remain in G 2 / M phase. Results the easy apoptosis and even the mitotic cell apoptosis. Vif could inhibit the activity of antiviral factor APOBEC3G and enhance the infection of virus. Vif could also make the cell cycle stay in G 2 / M phase. In this study, 61 patients with HIV-1 / AIDS and 10 healthy controls with negative HIV antibody were selected as subjects. CD4 cell count, viral load detection and general clinical data were collected. A total of 142 peptide segments covering the HIV-1 BU C subtype C subsidiary protein, Nef-Vpu-Vpr and Vif-, were used as antigens to stimulate the production of interferon 纬 by CTL from the study subjects. Elisa assay was used to detect quantitatively the specific CD8 T cell response of HIV-1 satellite protein. The response of HIV-1 dependent protein specific CD8 T cells in Chinese population was studied. In this study, we found that both HIV-1B subtype and HIV-1C subtype adjunct protein can produce specific CTL response. In particular, the response frequency and cumulative response intensity of Nef protein were higher than that of P0.001C subtype. There was no significant difference in the response frequency and cumulative response intensity between the two subtypes, and the immune dominant region was similar, and the immune dominant region of the accessory protein region was screened out. The specific cumulative CTL response intensity of accessory protein was nearly 21% of the total response. These results suggest that although the sequence of HIV-1 satellite proteins is short, they play an important role in inducing specific CTL responses. In conclusion, we preliminarily studied the CTL response characteristics of HIV-1 satellite protein, evaluated the role of HIV-1 accessory protein specific CTL response in CTL response induced by HIV-1, and determined the dominant region of CD8 T cell response in HIV-1 accessory protein region. It lays a foundation for further screening of CTL epitopes and preparation of safe and effective HIV-1 vaccine.
【学位授予单位】：第四军医大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R392

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中国期刊全文数据库 前2条

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本文编号：1908456