A novel VLP vaccine to prevent EBV infection and EBV - associated malignancies

项目摘要 伯基特淋巴瘤（BL）是撒哈拉以南非洲最常见的儿童癌症， 其他形式的儿科肿瘤的组合。BL如果不治疗是致命的;然而，目前的治疗方法 （强化化疗）只有50%的有效性，在撒哈拉以南非洲地区难以实施。迄今为止 绝大多数非洲BL病例与EB病毒（EBV）感染有关。因此，有一个 迫切需要一种安全有效的疫苗来预防和治疗EBV及其相关疾病。 拟定研究的目的是开发、表征和验证gp 42-gH/gL-EBNA 1-LMP 2 病毒样颗粒（VLP）作为抗EBV的候选疫苗的临床前研究。的先前方法 EBV疫苗的开发受到限制，部分原因是病毒基因组的致癌潜力， 缺乏测试候选疫苗的动物模型。这项建议将研究一项新的战略， 和有效的抗EBV的疫苗，使用能够呈递正确折叠的EBV蛋白的VLP。针对这两个 抗体介导的和T细胞介导的免疫系统的手臂-疫苗将纳入多个 EBV表面和细胞内抗原。EBV蛋白复合物gp 42-gH/gL和肿瘤相关的Epstein- 巴尔核抗原1（EBNA 1）和潜伏膜蛋白（LMP 2）是用于EBV的主要候选物 疫苗研发。有强有力的证据表明，EBV蛋白复合物gp 42-gH/gL的抗体可 中和EB病毒感染EBNA 1和LMP 2在所有EBV+ BL患者的B细胞中一致表达， 被CD 4+和CD 8 + T细胞识别。因此，我们假设gp 42-gH/gL-EBNA 1-LMP 2 VLP将 在体外和体外培养中产生强有力的EBV中和抗体应答和EBV特异性T细胞应答。 人源化小鼠模型。VLP将使用野生型小鼠（Aim 1）、BL的体外模型（目的2）和人源化小鼠（目的2） 一种多价疫苗，其既诱导预防性中和抗体，又诱导治疗性人类免疫应答， T细胞应答不仅是预防EBV感染的宝贵候选疫苗， 这在预防和/或治疗EBV相关疾病中至关重要。如果疫苗具有免疫原性， 在完成提案后，我们将利用现有的良好生产规范设施， City of Hope将大规模生产临床级gp 42-gH/gL-EBNA 1-LMP 2 VLP，并开始1期临床试验 在10-15名健康成人中进行的研究，以确定候选药物的安全性特征并确定其保护功效 疫苗从长远来看，如果成功的话，我们的方法将引入一种新的预防/治疗疫苗， 该市场具有预防或治疗每年超过20万例与EBV相关的癌症病例的潜力， 包括24,000例非洲儿童的BL病例。

PROJECT SUMMARY Burkitt lymphoma (BL) is the most common childhood cancer in sub-Saharan Africa, outnumbering all other forms of pediatric tumors combined. BL is lethal if left untreated; however, the current treatment (intensive chemotherapy) is only 50% effective and difficult to implement in sub-Saharan Africa. To date, the vast majority of African cases of BL are associated with Epstein-Barr virus (EBV) infection. Thus, there is a critical need for a safe and effective vaccine to prevent and treat EBV and its associated diseases. The objective of the proposed study is to develop, characterize, and validate gp42-gH/gL-EBNA1-LMP2 virus-like particles (VLPs) in pre-clinical studies as a candidate vaccine against EBV. Previous approaches to EBV vaccine development have been limited due in part to the oncogenic potential of the virus genome and lack of animal models to test vaccine candidates. This proposal will examine a new strategy to develop a safe and effective vaccine against EBV, using VLPs that can present properly folded EBV proteins. To target both arms of the immune system—antibody-mediated and T-cell mediated—the vaccine will incorporate multiple EBV surface and intracellular antigens. The EBV protein complex gp42-gH/gL and tumor-associated Epstein- Barr nuclear antigen 1 (EBNA1) and latent membrane protein (LMP2) are prime candidates for use in EBV vaccine development. There is strong evidence that antibodies to the EBV protein complex gp42-gH/gL can neutralize EBV infection. EBNA1 and LMP2 are consistently expressed in B cells of all EBV+ BL patients and are recognized by CD4+ and CD8+ T cells. Thus, we hypothesize that gp42-gH/gL-EBNA1-LMP2 VLPs will generate robust EBV-neutralizing antibody responses and EBV-specific T-cell responses in vitro and in a humanized mouse model. The VLPs will be generated, characterized, and validated using wild-type mice (Aim 1), an in vitro model of BL (Aim 2), and humanized mice (Aim 2) A polyvalent vaccine that induces both prophylactic neutralizing antibodies and elicits therapeutic human T-cell responses will not only be an invaluable candidate vaccine in preventing EBV infection, but also of utmost importance in preventing and/or treating EBV-associated disease. If the vaccine is immunogenic, following completion of the proposal, we will utilize the current good manufacturing practice facility available at City of Hope to mass-produce clinical grade gp42-gH/gL-EBNA1-LMP2 VLPs and begin a phase 1 clinical study in 10-15 healthy adults to establish safety profiles and determine the protective efficacy of the candidate vaccine. In the long term, if successful, our approach will introduce a new prophylactic/therapeutic vaccine to the market with a potential for preventing or treating over 200,000 annual cancer cases associated with EBV, including 24,000 cases of BL in African children.