Human T Cell Responses to Vaccinia Vaccine

描述（由申请人提供）：迫切需要开发更安全的天花疫苗。一种方法是使用改良的安卡拉牛痘病毒（MVA），这是一种高度减毒的牛痘病毒，不会在人类细胞中复制。然而，与牛痘病毒相比，MVA的免疫原性较低，可能需要更高的剂量和更频繁的加强。还存在关于使用减毒活病毒和可能存在外源性病原体的安全性问题。替代方法包括开发灭活病毒或重组蛋白疫苗。然而，疫苗的开发受到阻碍，因为人们对哪些蛋白质在产生对天花的保护性免疫反应中起重要作用知之甚少。最近，鉴定了4种诱导中和抗体的包膜蛋白，并且用所有4种基因的组合进行DNA疫苗接种保护小鼠免受致命的牛痘感染。尽管疫苗需要诱导强烈的T细胞反应，除了中和抗体，没有关于T细胞识别的牛痘蛋白靶点的信息。特别地，需要CD 4 T细胞来增强对裂解性病毒的B细胞、T细胞和先天性免疫应答。作为第一步，将测试来自先前用牛痘病毒免疫的健康成人的外周血单核细胞的病毒特异性T细胞应答。本研究的目的是：1）测量人T细胞对牛痘结构蛋白的应答频率; 2）鉴定上述4种包膜蛋白内的主要CD 4和CD 8 T细胞表位; 3）分析接种后T细胞对这些表位的应答频率。预计这项工作将为检测和监测大多数人的牛痘特异性T细胞反应提供新的工具，并将有助于开发天花疫苗开发的新策略。

DESCRIPTION (provided by applicant): There is an urgent need to develop safer smallpox vaccines. One approach is the use of modified vaccinia virus Ankara (MVA), a highly attenuated vaccinia virus that does not replicate in human cells. In comparison to vaccinia virus, however, MVA is less immunogenic and may require higher doses and more frequent boosts. There also remain safety concerns about the use of a live attenuated virus and the potential presence of adventitious pathogens. Alternative approaches include the development of inactivated virus or recombinant protein vaccines. However, vaccine development is hampered because little is known about what proteins play an important role in the generation of protective immune responses to smallpox. Recently, 4 envelope proteins that induce neutralizing antibodies were identified, and DNA vaccination with a combination of all 4 genes protected mice from a lethal vaccinia infection. Although a vaccine will need to induce strong T cell responses, in addition to neutralizing antibodies, no information is available about the vaccinia protein targets recognized by T cells. In particular, CD4 T cells are required to enhance B cell, T cell, and innate immune responses to lytic viruses. As a first step, peripheral blood mononuclear cells from healthy adults previously immunized with vaccinia virus will be tested for virus-specific T cell responses. The goals of this study are: 1) to measure the frequencies of human T cell responses to vaccinia structural proteins; 2) to identify major CD4 and CD8 T cell epitopes within the above 4 envelope proteins; and 3) to analyze the frequencies of the T cell responses to these epitopes post-vaccination. It is anticipated that this work will provide new tools for the detection and monitoring of vaccinia-specific T cell responses from most individuals and will help develop new strategies for smallpox vaccine development.