B cell based protection against recurrent herpes

项目摘要 单纯疱疹病毒2型（HSV-2）是最常见的性传播感染（STI）之一， 在美国的患病率为4500万。HSV-2主要通过暴露于生殖器粘膜传播 表面，这导致在骶神经节中建立潜伏期。虽然药理学 对于HSV-2相关症状存在干预措施，没有预防性疫苗或治疗措施 可用于这种疾病。为了开发预防HSV-2传播的疫苗， 免疫应答在相关粘膜部位介导的机制是必要的。 目前，对女性生殖器粘膜内的免疫保护机制知之甚少。我们 以前的研究使我们了解到，记忆T细胞循环到阴道是受到限制的， 状态（Nakanishi等人，Nature，2009）。基于这种认识，我们开发了一种新的疫苗策略， “预充和拉动”，其中在肠胃外接种后局部应用趋化因子建立局部免疫。 记忆性CD 8 T细胞以显著改善由肠胃外疫苗提供的保护（Shin和Iwasaki， Nature，2012）。我们还表明，阴道内（ivag）免疫与TK- HSV-2提供了局部 基于建立CD 4组织驻留记忆T（TRM）细胞的保护（Iijima和Iwasaki，Science， 2014）。我们的初步研究表明，记忆B细胞必须迁移到女性生殖道 (FRT)以重新刺激CD 4 TRM。引人注目的是，与T细胞不同，B细胞不会成为组织驻留细胞，而是 相反，作为“访客”或B访客记忆（BGM），组成性地进入FRT并响应HSV-2感染 细胞TRM的记忆B细胞参与导致其分泌抗病毒细胞因子IFN-γ以及B辅助细胞 细胞因子IL-21。因此，在TRM存在下，BGM被诱导分泌病毒特异性IgG。 FRT。这项拨款申请的目的是了解保护性免疫的机制， HSV-2是由女性生殖道中的BGM编排的，并且为了将这种理解应用于设计一种稳健的 生殖器疱疹的治疗方法有哪些？我们建议解剖 病毒攻击后局部免疫宿主中B细胞募集至FRT的机制（目的1）， 确定刺激CD 4 TRM的记忆B细胞亚群的身份（目的2），并确定 CD 4帮助记忆B细胞转化为分泌抗体的浆细胞（目的3）。通过 提供迁移记忆B细胞和CD 4 TRM如何介导抗HSV保护的基本理解- 2生殖器感染，并应用这些知识来设计更好的疫苗方法，这些研究将有助于 为设计免疫干预和预防措施奠定重要基础 预防生殖器疱疹和其他有害的性病。

Project Summary Herpes simplex virus-2 (HSV-2) is one of the most common sexually transmitted infections (STIs) with a high prevalence of 45 million in the USA. HSV-2 is primarily transmitted via exposure at the genital mucosal surfaces, which leads to the establishment of latency in the sacral ganglia. Although pharmacological interventions exist for HSV-2-related symptoms, there are no preventative vaccines or curative measures available for this disease. Towards developing vaccines to prevent HSV-2 transmission, a clear understanding of the mechanism by which immune responses are mediated within the relevant mucosal sites is necessary. Currently, the immune mechanisms of protection within the female genital mucosa are poorly understood. Our previous studies led to the understanding that memory T cell circulation to the vagina is restricted at steady state (Nakanishi et al, Nature, 2009). Based on this insight, we developed a new vaccine strategy we call, “Prime and Pull”, in which topical application of chemokines following parenteral vaccination establishes local memory CD8 T cells to dramatically improve protection afforded by parenteral vaccines (Shin and Iwasaki, Nature, 2012). We have also shown that intravaginal (ivag) immunization with TK- HSV-2 provides local protection based on establishment CD4 tissue resident memory T (TRM) cells (Iijima and Iwasaki, Science, 2014). Our Preliminary Studies reveal that memory B cells must migrate into the female reproductive tract (FRT) in order to restimulate the CD4 TRM. Strikingly, unlike T cells, B cells do not become tissue-resident, but rather, enter the FRT constitutively and in response to HSV-2 infection as “guest”, or B guest memory (BGM) cells. Memory B cell engagement of TRM results in their secretion of antiviral cytokine IFN-γ as well as B helper cytokine, IL-21. Consequently, BGM are induced to secrete virus-specific IgG in the presence of TRM within the FRT. The goal of this grant application is to understand the mechanism by which protective immunity against HSV-2 is orchestrated by BGM in the female genital tract, and to apply this understanding to design a robust vaccine against recurrent genital herpes through the following Specific Aims. We propose to dissect the mechanism of B cell recruitment to the FRT in locally immunized host following viral challenge (Aim 1), to determine the identity of memory B cell subset that stimulates CD4 TRM (Aim 2), and to determine the nature of CD4 help provided to memory B cells that converts them into antibody secreting plasma cells (Aim 3). By providing basic understanding of how migrating memory B cells and CD4 TRM mediate protection against HSV- 2 genital infection, and applying such knowledge to design a better vaccine approach, these studies will help to establish important foundation with which to design immunological interventions and preventative measures against genital herpes and other deleterious STI diseases in humans.