DEVELOPMENT OF HEPATITIS C VIRUS-LIKE PARTICLES AS CANDIDATE HCV VACCINE

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目及 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 目前，还没有预防HCV感染的疫苗可用，并且该流行病在世界范围内继续有增无减。本研究的目的是开发一种由HCV样颗粒组成的候选HCV疫苗，并在黑猩猩模型中评价疫苗的免疫原性。 四只未感染HCV的黑猩猩用佐剂和免疫刺激复合物配制的HCV-VLP疫苗免疫。用感染性HCV攻毒接种疫苗的动物，以确定疫苗预防感染的效力。 在昆虫细胞中产生的含有HCV结构蛋白（核心、E1和#2）的重组丙型肝炎病毒（HCV）样颗粒（HCV-LP）类似于推定的HCV病毒体，并且能够在小鼠和狒狒中诱导强烈和广泛的体液和细胞免疫应答。 在这里，我们提出的证据的免疫原性和诱导的保护性免疫的HCV-LPs在黑猩猩。 用HCV-LP或HCV-LP加AS 01 B佐剂免疫黑猩猩（每组2只）。 免疫后，所有动物均产生HCV特异性免疫应答，包括IFN-γ +、IL-2+、CD 4+和CD 8 + T细胞以及针对核心、E1和#2的增殖性淋巴细胞应答。 在用感染性HCV接种物挑战后，一只黑猩猩在挑战后第三和第四周出现了一过性病毒血症，HCV RNA滴度较低（103至104拷贝/ml）。 其他三只黑猩猩感染了更高水平的病毒血症（每毫升104至105个拷贝），但在攻击后10周，它们的病毒水平变得无法量化（每毫升103个拷贝）。 HCV攻击后，所有四只黑猩猩表现出对HCV结构蛋白的外周和肝内T细胞和增殖反应的显着增加。 这些T细胞和增殖反应与HCV RNA水平的下降一致。 四纳5只黑猩猩感染了相同的HCV接种物，3只出现了持续感染，病毒血症更高，范围为105至106拷贝/ml。 我们的研究表明，HCV-LP免疫诱导HCV特异性细胞免疫反应，可以控制HCV的攻击在黑猩猩模型。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. At the present time, no vaccines to prevent infection with HCV are available and the epidemic continues unabated worldwide. The objectives of this study are to develop a candidate HCV vaccine consisting of HCV-like particles and to evaluate the immunogenicity of the vaccine in the chimpanzee model. Four HCV na¿ve chimpanzees were immunized with HCV-VLP vaccine formulated with adjuvants and immunostimulatory complexes. The vaccinated animals have been challenged with infectious HCV to determine the efficacy of the vaccine preventing infection. Recombinant hepatitis C virus (HCV)-like particles (HCV-LPs) containing HCV structural proteins (core, E1, and #2) produced in insect cells resemble the putative HCV virions and are capable of inducing strong and broad humoral and cellular immune responses in mice and baboons. Here, we present evidence on the immunogenicity and induction of protective immunity by HCV-LPs in chimpanzees. Chimpanzees (two in each group), were immunized with HCV-LPs or HCV-LPs plus AS01B adjuvant. After immunizations, all animals developed an HCV-specific immune response including IFN-¿+, IL-2+, CD4+, and CD8+ T cell and proliferative lymphocyte responses against core, E1, and #2. Upon challenge with an infectious HCV inoculum, one chimpanzee developed transient viremia with low HCV RNA titers (103 to 104 copies per ml) in the third and fourth weeks after the challenge. The three other chimpanzees became infected with higher levels of viremia (104 to 105) copies per ml), but their viral levels became unquantifiable (103 copies per ml) 10 weeks after the challenge. After the HCV challenge, all four chimpanzees demonstrated a significant increase in peripheral and intrahepatic T cell and proliferative responses against the HCV structural proteins. These T cell and proliferative responses coincided with the fall in HCV RNA levels. four na¿ve chimpanzees were infected with the same HCV inoculum, and three developed persistent infection with higher viremia in the range of 105 to 106 copies per ml. Our study suggests that HCV-LP immunization induces HCV-specific cellular immune responses that can control HCV challenge in the chimpanzee model.