Development of Vaccines Against Retrovirus Infection in

逆转录病毒感染疫苗的开发

• 批准号: 6761575
• 负责人: RAOUL BENVENISTE
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6761575
• 关键词: AIDS vaccines; HIV envelope protein gp160; MHC class I antigen; MHC class II antigen; Macaca; antiviral antibody; biotechnology; cellular immunity; drug design /synthesis /production; drug screening /evaluation; human immunodeficiency virus 1; human tissue; immunization; isoantibody; molecular cloning; nonhuman therapy evaluation; recombinant virus; simian immunodeficiency virus; surface antigens; tissue /cell culture; vaccine development; vaccinia virus; vector vaccine; viral vaccines; virus infection mechanism; virus protein

Our studies have focused on the the development of vaccines and the testing of antivirals. Using our pathogenic molecular clones (SIV/Mne) obtained from a pigtailed macaque naturally infected with AIDS, we have also examined the virologic and molecular changes in SIV that are associated with progression to AIDS. The time interval between infection and death, expressed as a precentage of total life span, is very similar between macques infected with these SIV clones and humans infected with HIV-1. These SIV/Mne viruses have therefore been used by several investigators as challenge stocks for a variety of AIDS vaccine protocols. 1. Role of cellular antigens in AIDS vaccines. Macaques immunized with uninfected human cells have been shown to be protected from challenge with SIV propagated in human cells. In collaboration with Drs. L. Arthur and L. Henderson, we have shown that various cellular antigens (including beta-2 microglobulin (beta-2M), HLA class I and HLA class II DR) are specifically associated with purified preparations of HIV and SIV. To identify the potential antigens involved in protection, macaques were immunized with beta-2M or with HLA class I or class II DR purified from H9 cells. Although all macaques developed humoral immune responses to these proteins, only the macaques immunized with HLA DR were protected from a subsequent challenge with HIV grown in H9 cells. This was the first demonstration that immunization with a cellular protein can protect from an AIDS virus infection. The study described above represents xenoimmunization - the use of human HLA molecules to immunize macaques. These studies have now been extended to alloimmunization studies - a study of the role of macaque class II antigens in protecting from AIDS virus infection (alloimmunization studies). In collaboration with Dr. M. Carrington, we have identified class II alleles in the pigtailed macaque colony at the University of Washington, and obtained class II DR from microvesicles harvested from Herpesvirus papio transformed macaque B-lymphocytes. Macaques that share similar and distinct class II alleles (as determined by oligotyping) were immunized with microvesicles containing DR, and then challenged with SIV/Mne grown in lymphocytes from the animal from which the class II antigen was purified. Animals have been monitored for evidence of viral infection, plasma loads of viral RNA and for the development of anibodies to SIV. All macaques became infected - antibodies to class II did not correlate with protection from infection in an alloimmunization regimen. The reasons why protection was evident in the xenoimmunization but not in the alloimmunization experiment are being pursued. Possibilities include the different species of macaques used in the two studies, and the manner in which the cellular antigens were presented. 2. Recombinant SIV vaccines. We previously reported that immunization with recombinant SIVmne envelope (gp160) vaccines protected macaques against intravenous challenge by the cloned homologous virus, E11S, but protection was only partially effective (43%) against an uncloned stock of SIVmne. To examine the role of core antigens in inducing or broadening protective immunity against intravenous challenges by heterologous viruses, we immunized macaques with either envelope, core proteins, or both antigens formulated as a mixture. Animals immunized with core antigens alone were not protected even against the homologous virus challenge, although the virus load was 100-fold lower than that of control (non-immunized) animals, suggesting an important role for core antigen-specific immune responses in controlling the acute infection. Animals that received both envelope and core antigens were now protected against an intravenous heterologous virus challenge, indicating that responses to core antigens contributed to the broadening of protective immunity. The results from these systematic studies argue strongly for the inclusion of multiple antigens in the design of recombinant vaccines against AIDS. 3. Role of cell-mediated immunity in AIDS vaccines. A possible role for cell-mediated immunity (CMI) in protection against HIV infection is suggested by the finding that a significant number of potentially HIV-exposed individuals from different risk groups, who show no evidence of infection, exhibit a strong HIV-specific CMI. To test this hypothesis in the SIV-macaque model, we inoculated macaques with graded doses of SIV and examined these animals for SIV viral sequences and the development of immune responses. Macaques inoculated with doses of SIV below the threshold required for virus isolation or seroconversion exhibited lymphocyte proliferation and were protected from an infectious SIV challenge delivered 16 months later. Additional studies are planned that will compare both aldrithiol-2 inactivated and live virus delivered at a similar subinfectious dose. 4. Development of primate vaccines that protect against natural type D retorvirus infection. Infectious type D retroviruses (SRVs) produce a naturally occurring and often fatal disease originally observed among macaques housed at primate centers in the United States. Five neutralization types have been identified (SRV1 - SRV5), three of which have been molecularly cloned and sequenced (SRV-1, 2, and 3). These infectious type D retroviruses cause an often-fatal immunosuppressive disease in macaques that is manifested by progressive weight loss, persistent diarrhea, anemia, thymic and lymphoid atrophy, opportunistic infections, and unusual neoplasms. Since the experimental infection of macaques with SIV results in similar clinical outcomes, animals used in AIDS experiments must be free of these SRV retroviruses so as not to confound pathogenesis and vaccine studies. It has therefore become important to eradicate and prevent type D retrovirus infections among captive, group-housed macaques maintained at primate centers. The primary objective of these experiments is to develop a safe and efficacious vaccine against SRV that can be used by primate centers in order to protect these valuable animals from these naturally occurring infections. We have previously reported that a vaccinia virus, recombined with and expressing the envelope proteins of our molecular clone of SRV-2, completely protected immunized macaques from a challenge with up to one million infectious SRV-2 particles delivered intravenously. This report was the first to describe that a recombinant vaccine could completely protect against a primate retrovirus infection. Future studies are now planned to test whether this vaccine will protect in a more natural setting; for example, among group-housed macaques in a colony setting. Macaques will be immunized with recombinant vaccinia virus expressing the envelope glycoproteins of SRV-2, SRV-1, and both recombinant vaccines and subsequently exposed to animals naturally infected with SRV-2. Control macaques, similarly exposed, will be immunized with wild-type vaccinia virus. Animals that are protected from this natural challenge will then be exposed to macaques infected with other type D retroviruses (SRV-1), in an effort to determine the limits and the correlates of the protective immunity elicited by these vaccines. Future experiments may also include recombinant vaccinia virus expressing Gag and Pol viral proteins to measure whether the inclusion of these additional antigens broadens the protective response as they do for SIV vaccines.

我们的研究集中在疫苗的开发和抗病毒药的测试上。使用我们从自然感染了艾滋病的锯齿状猕猴获得的病原分子克隆（SIV/MNE），我们还研究了与辅助剂进展有关的SIV病毒学和分子变化。感染和死亡之间的时间间隔表示为总寿命的预先范围，在感染了这些SIV克隆和感染HIV-1的人类的误素之间非常相似。因此，这些SIV/MNE病毒已被几个研究人员用作各种艾滋病疫苗方案的挑战股。 1。细胞抗原在艾滋病疫苗中的作用。用未感染的人类细胞免疫的猕猴已被证明可以保护人类细胞中SIV的挑战。与Drs合作。 L. Arthur和L. Henderson，我们已经表明，各种细胞抗原（包括β-2微球蛋白（β-2M），HLA I类和HLA II类DR）与HIV和SIV的纯化制剂特别相关。为了鉴定涉及保护涉及的潜在抗原，猕猴通过β-2M或HLA I类或II类DR从H9细胞中进行了免疫。尽管所有猕猴都会对这些蛋白质产生体液免疫反应，但仅保护了用HLA DR免疫的猕猴受到HIV在H9细胞中生长的HIV的挑战。这是第一次证明用细胞蛋白免疫可以保护艾滋病病毒感染。 上面描述的研究代表异种免疫 - 使用人HLA分子免疫猕猴。这些研究现已扩展到同种免疫研究 - 对猕猴II类抗原在保护AIDS病毒感染中的作用（同种免疫研究）。与M. Carrington博士合作，我们确定了华盛顿大学的锯齿状猕猴殖民地中的II类等位基因，并从从疱疹病毒Papio转化的猕猴B淋巴细胞中收获的微伏层中获得了II级DR。具有相似且独特的II类等位基因（由寡型型）的猕猴用含有DR的微囊泡进行免疫，然后用来自从中纯化II类抗原的动物的淋巴细胞中生长的SIV/MNE挑战。已经监测了动物的病毒感染，病毒RNA的血浆载荷以及向SIV的芳香族发育的证据。所有猕猴都被感染了 - II类的抗体与在同种免疫方案中免受感染的保护无关。在Xenomumunization中显而易见的保护而不是在同种免疫实验中进行保护的原因。可能性包括两项研究中使用的不同种类的猕猴，以及呈现细胞抗原的方式。 2。重组SIV疫苗。我们先前曾报道过，重组SIVMNE包膜（GP160）疫苗免疫保护猕猴免受克隆的同源病毒E11S的静脉挑战，但保护仅是部分有效的（43％），以防止未封闭的Sivmne股票。为了检查核心抗原在诱导或扩大异源病毒静脉挑战的保护性免疫中的作用，我们用包膜，核心蛋白或两种抗原作为混合物进行了免疫猕猴。尽管病毒负荷比对照（非免疫化）动物低100倍，但仅用核心抗原免疫的动物也没有受到保护，即使免受同源病毒的挑战，这表明在控制急性感染中核心抗原特异性免疫反应起着重要作用。现在可以保护接受包膜和核心抗原的动物免受静脉异源性病毒挑战，这表明对核心抗原的反应有助于扩大保护性免疫。这些系统研究的结果强烈表明，将多种抗原纳入针对艾滋病的重组疫苗的设计。 3。细胞介导的免疫在艾滋病疫苗中的作用。细胞介导的免疫（CMI）在防御HIV感染中的可能作用，这是通过发现没有表现出没有感染证据的不同风险群体的大量潜在艾滋病毒暴露的个体表现出强大的HIV特异性CMI的发现。为了在SIV-Macaque模型中检验这一假设，我们用分级剂量的SIV接种猕猴，并检查了这些动物的SIV病毒序列和免疫反应的发展。猕猴接种了SIV剂量以下，低于病毒分离或血清转化所需的阈值，表现出淋巴细胞增殖，并受到16个月后提供的感染性SIV挑战的保护。还计划了其他研究，该研究将比较以类似的亚感染剂量灭活的Aldrithiol-2灭活和活病毒。 4。开发可预防自然D型重复病毒感染的灵长类动物疫苗。 D型D型逆转录病毒（SRV）最初在美国灵长类动物中心内部观察到的猕猴自然存在且通常是致命的疾病。已经鉴定出五种中和类型（SRV1 -SRV5），其中三种已被分子克隆并测序（SRV -1、2和3）。这些感染性的D型逆转录病毒会导致猕猴中通常一种致命的免疫抑制性疾病，这种疾病表现为进行性体重减轻，持续性腹泻，贫血，胸腺症和淋巴样萎缩，机会性感染和不寻常的肿瘤。由于具有SIV猕猴的实验感染会导致相似的临床结局，因此在AIDS实验中使用的动物必须释放这些SRV逆转录病毒，以免混淆发病机理和疫苗研究。因此，在灵长类动物中心维持的圈养，群猕猴之间消除和防止D型逆转录病毒感染变得重要。这些实验的主要目的是开发一种针对SRV的安全有效的疫苗，灵长类动物中心可以使用，以保护这些有价值的动物免受这些天然发生的感染。我们以前已经报道说，一种与SRV-2分子克隆的包络蛋白重新组合并表达了SRV-2的包膜蛋白，完全保护了免疫猕猴，并从一百万个感染性SRV-2颗粒静脉内传递。该报告是第一个描述重组疫苗可以完全预防灵长类动物逆转录病毒感染的报告。现在计划未来的研究来测试这种疫苗是否会在更自然的环境中保护；例如，在殖民地环境中的团体猕猴中。猕猴将用表达SRV-2，SRV-1的包膜糖蛋白以及重组疫苗的包膜糖蛋白以及随后暴露于自然感染SRV-2的动物的情况下进行免疫。对照猕猴（类似暴露）将用野生型离与病毒免疫。然后，受到保护免受自然挑战的动物将暴露于感染其他D型逆转录病毒（SRV-1）的猕猴，以确定这些疫苗引起的保护性免疫的极限和相关性。未来的实验还可能包括表达GAG和POL病毒蛋白的重组疫苗病毒，以测量包含这些额外的抗原是否会像对SIV疫苗一样扩大保护性反应。