Enhancing neonatal immunity to Streptococcus pneumoniae

描述（由申请方提供）：拟议研究的总体目标是评价婴儿对候选肺炎球菌疫苗的免疫应答。Malley实验室和其他地方的研究揭示了CD 4 + T细胞在提供保护以对抗肺炎球菌定植中的作用。在Malley实验室开发的全细胞疫苗（WCV）将进入I期临床试验，提供双管齐下的预防肺炎球菌的保护：CD 4 + Th 17依赖性预防定植和非荚膜抗体介导的预防侵袭性疾病。初步研究表明，虽然幼年小鼠对全细胞疫苗有反应并受到保护，免受肺炎球菌定植，但与成年小鼠相比，它们的CD 4 + T细胞反应降低，保护作用较低。了解抑制婴儿对WCV的强烈T细胞应答的因素将有助于指导更高免疫原性疫苗和佐剂的开发，并为临床试验期间的免疫学评估提供信息。 IL-10是Th 17应答的有效抑制剂，并且我们已经表明，新生巨噬细胞在对肺炎球菌抗原刺激的应答中比成年小鼠的巨噬细胞产生显著更多的IL-10。因此，我们建议检验以下假设：婴儿中WCV的免疫原性和疗效降低主要是由于新生儿抗原呈递细胞产生的IL-10和其他抑制性细胞因子增加。在目标1中，我们将使用转基因小鼠和Horwitz实验室开发的独特IL-10试剂的组合，以确定新生儿巨噬细胞产生的IL-10是否减弱疫苗接种后的保护性Th 17应答。在目标2中，我们将通过比较细胞内NF-κB和ERK信号通路以及细胞外IFN-κB/IL-27轴（它们参与调节IL-10的产生）来确定新生巨噬细胞产生IL-10水平升高的原因。在第三个也是最后一个目标中，将在非人灵长类动物模型中评估这些先天性和获得性免疫应答。我们将研究新生儿，年轻和成年恒河猴，这将提供重要的信息，先天性免疫反应的性质肺炎球菌，特别是这种疫苗的巨噬细胞的反应。新生儿、年轻和成年恒河猴将使用药品生产质量管理规范（GMP）级全细胞疫苗进行免疫，并详细分析其免疫（T细胞和抗体）应答。总的来说，这些研究将为婴儿与成人对候选肺炎球菌疫苗的免疫反应提供重要的见解，并将指导该疫苗进入临床试验时的进一步研究。

DESCRIPTION (provided by applicant): The overall objective of the proposed research is to evaluate the immunological response of infants to a candidate pneumococcal vaccine. Investigations in the Malley laboratory and elsewhere have revealed the role of CD4+ T cells in providing protection against pneumococcal colonization. The whole cell vaccine (WCV) developed in the Malley laboratory, which will be entering Phase I clinical trials, confers a two-pronged protection against pneumococcus: CD4+ Th17-dependent protection against colonization and non-capsular antibody-mediated protection against invasive disease. Preliminary studies have shown that while infant mice respond to the whole cell vaccine and are protected against pneumococcal colonization, they nevertheless have a reduced CD4+ T cell response and lower protection when compared to adult mice. Understanding the factors that inhibit a robust T cell response to WCV in infants will help guide development of more highly immunogenic vaccines and adjuvants, and inform immunological assessment during clinical trials. IL-10 is a potent inhibitor of Th17 responses, and we have shown that neonatal macrophages make significantly more IL-10 in response to stimulation with pneumococcal antigen than macrophages from adult mice. Therefore we propose to test the hypothesis that reduced immunogenicity and efficacy of WCV in infants is primarily due to increased production of IL-10 and other inhibitory cytokines by neonatal antigen presenting cells. In Aim 1 we will use a combination of transgenic mice and unique IL-10 reagents developed in the Horwitz laboratory to determine whether IL-10 produced by neonatal macrophages attenuates the protective Th17 response following vaccination. In Aim 2 we will determine why neonatal macrophages produce enhanced levels of IL-10 by comparing the intracellular NF-κB and ERK signaling pathways, as well as the extracellular IFN-ß/IL-27 axis that have been implicated in regulating IL-10 production. In the third and final aim, these innate and acquired immune responses will be evaluated in a nonhuman primate model. We will examine the macrophage response in neonatal, young and adult rhesus macaques, which will provide important information regarding the nature of the innate immune response to pneumococcus and this vaccine in particular. Neonatal, young and adult rhesus macaques will be immunized with Good Manufacturing Practice (GMP)-grade whole cell vaccine and their immune (T cell and antibody) responses analyzed in detail. Overall, these investigations will provide important insight into the immune response to a candidate pneumococcal vaccine in infants vs. adults and will guide further studies of this vaccine as it enters clinical trials.