Pneumococcal immunization through a novel mechanism

所述荚膜多糖-蛋白质缀合物疫苗通过以下方式有效预防侵袭性疾病： 包括血清型的肺炎链球菌（肺炎球菌），但制备和施用成本高， 对中耳炎的有效性最低，并进行血清型替换（其中不包括 血清型变得更普遍）。因此，需要新的免疫方法。 我们意外地发现，小鼠鼻内免疫肺炎球菌细胞壁多糖， (CWPS所有血清型共有的抗原）对鼻咽定殖产生持久的抗性 和中耳感染不同血清型的肺炎球菌。疫苗的保护作用（即 CWPS +粘膜佐剂）不依赖于抗体，并依赖于CD 4 + T细胞的存在。 这种多糖诱导的、细胞介导的粘膜免疫， 据我们所知，被包裹的细菌以前没有被证明，因此代表 a novel新approach方法to vaccination疫苗. 我们假设CWPS的两性离子性质在引发这种T细胞依赖性的免疫反应中是至关重要的。 反应我们的第一个目标是通过进一步纯化确定CWPS保护的结构基础， 聚合物合成、改变两性离子基序的化学修饰、自偶联或偶联到两性离子基序上。 蛋白质载体因此，要么zwitzerland假说将得到证实和/或最低限度的保护结构， 将被定义。其次，我们将更详细地研究CD 4 + T细胞赋予免疫应答的机制。 防止肺炎球菌定植。连续转移实验将表征 保护性T细胞反应。进一步的方法将包括通过使用 敲除小鼠或给予细胞因子、中性粒细胞耗竭实验和组织病理学， 共聚焦显微镜在第三个目标中，我们将评估先天性免疫应答在调节 通过使用Toll样受体（TLR）敲除小鼠和共施用 TLR配体作为免疫时的佐剂。 我们的研究将增加对肺炎球菌定植免疫的基本理解，并可能导致 一种简单的、确定的、可能是合成的疫苗，它将补充或取代多价荚膜梭菌， 在针对这种儿童高度流行的病原体的疫苗接种中，

The capsular polysaccharide-protein conjugate vaccine is effective in prevention of invasive disease by Streptococcus pneumoniae (pneumococci) of the serotypes included but is costly to make and administer, minimally effective against otitis media, and subject to serotype replacement (in which non-included serotypes become more prevalent). Therefore, novel approaches to immunization are needed. We found unexpectedly that mice immunized intranasally with the pneumococcal cell wall polysaccharide (CWPS, an antigen commonto all serotypes) develop long-lasting resistance to nasopharyngeal colonization and middle ear infection with pneumococci of different serotypes. Strikingly, protection by the vaccine(i.e. CWPS + mucosal adjuvant) is independent of antibody and dependent on the presence of CD4+ T cells. This polysaccharide-induced, cell-mediated mucosal immunity against colonization by an "extracellular" encapsulated bacterium has not, to our knowledge, been previously demonstrated and therefore represents a novel approachto vaccination. We hypothesize that the zwitterionic property of CWPS is critical in eliciting this T-cell-dependent response. Our first goal is to determine the structural basis of protection by CWPS by further purification, polymer synthesis, chemical modifications to alter the zwitterionic motif, auto-coupling, or coupling to a protein carrier. Thus either the zwitterion hypothesis will be confirmed and/or the minimal protective structure will be defined. Secondly, we will examine in more detail the mechanisms whereby CD4+ T cells confer protection against pneumococcal colonization. Adoptive transfer experiments will characterize the nature of the protective T cell responses. Further approaches will include polarization of T cell responses by use of knockout mice or administration of cytokines, neutrophil depletion experiments, and histopathology with confocal microscopy. In a third aim, we will evaluate the role of innate immune responses in modulating acquired immunity to colonization, by use of Toll-like receptor (TLR) knockout mice and co-administration of TLR ligands as adjuvants at the time of immunization. Our studies will increase basic understanding of immunity to pneumococcal colonization and could lead to a simple, defined, and possibly synthetic vaccine that would complement or replace the multivalent capsular conjugates in vaccination against this, highly prevalent pathogen of children.