Novel Combination Adjuvant for Eliciting Systemic and Mucosal CD8 T Cell Memory

 说明(申请人提供)：鉴于与活疫苗相关的安全问题，疫苗配方越来越多地基于高度纯化的亚单位抗原和/或重组DNA技术产生的抗原。然而，这种抗原亚单位典型的免疫原性很差，需要使用佐剂来增强对疫苗中保护性表位的免疫反应。尽管进行了几十年的研究，但很少有佐剂获准在人类身上使用。与活疫苗不同，目前使用许可佐剂制成的灭活疫苗/亚单位疫苗通常免疫持续时间较短，主要诱导抗体应答，需要多次免疫才能维持保护性免疫，并引发较差的细胞免疫(CMI；TH1和CD8T细胞记忆)。因此，迫切需要确定能够产生平衡抗体和CMI的佐剂，以保护细胞外和细胞内的病原体。卡波姆是丙烯酸与聚烯基醚交联的聚合物，在制药工业中被广泛用作生物粘合剂，并在兽医和实验疫苗中用作佐剂。我们已经确定了一种卡波姆类佐剂，Adjuplex(ADJ)，它能像活病毒疫苗一样，引起强大的全身和粘膜CD4TH1和CD8T细胞反应。在这项建议中，作为一种联合佐剂，我们将利用ADJ诱导的CD4/CD8 T细胞反应来平衡和增强由临床测试的TLR激动剂葡萄糖吡喃糖脂A(GLA)和CpG引发的免疫反应。根据初步数据，我们假设ADJ是一种有效的具有免疫调节特性的抗原递送系统。我们进一步假设，ADJ与GLA和CpG结合构成了一种新的佐剂，它将ADJ的有效抗原递送和免疫调节特性与GLA和CpG的免疫增强作用结合起来，从而同时激活多个天然信号通路。在目标1中，我们将测试联合佐剂是否增加了系统和粘膜组织驻留记忆CD8T细胞以及抗体和CD4T细胞的分化和持久性。目的2研究联合佐剂是否以及如何在体外增强人和小鼠树突状细胞的交叉呈递过程。研究的机制将包括抗原摄取和靶向早期内小体，内体酸化和保留抗原，溶酶体和蛋白酶体的作用，抗原呈递给幼稚的T细胞和参与的信号通路。在目标3中，我们将确定联合佐剂是否以及如何增强体内的交叉呈现机制。这项拟议的工作有可能发现一种新的组合佐剂，该佐剂将在免疫细胞中参与多个信号通路，并利用单个组件的独特免疫刺激特性来产生平衡和持久的体液和CMI反应。这项工作的发现将具有非常重要的意义，预计将对针对不同病原体的有效疫苗的临床开发产生广泛影响。

 DESCRIPTION (provided by applicant): In light of the safety concerns associated with live vaccines, vaccine formulations are increasingly based on highly purified subunit antigens and/or antigens produced by recombinant DNA technology. However, the poor immunogenicity typical of such antigenic subunits necessitates the use of adjuvants to enhance the immune responses to the protective epitopes in the vaccine. Despite decades of research, very few adjuvants are licensed for use in humans. Unlike live vaccines, current inactivated/subunit vaccines formulated with the licensed adjuvants often confer shorter duration of immunity, largely induce antibody responses, require multiple immunizations to maintain protective immunity, and trigger poor cell-mediated immunity (CMI; TH1 and CD8 T cell memory). Therefore, there is a critical need to identify adjuvants that engender balanced antibody and CMI to protect against both extracellular and intracellular pathogens. Carbomers are polymers of acrylic acid cross-linked with polyalkenyl ethers, and are extensively used as bioadhesives in the pharmaceutical industry and as adjuvants in veterinary and experimental vaccines. We have identified a carbomer-class adjuvant, Adjuplex (ADJ) that elicits potent systemic and mucosal CD4 TH1 and CD8 T cell responses, like a live viral vaccine. In this proposal, as a combination adjuvant, we will leverage the CD4/CD8 T cell responses induced by ADJ to balance and potentiate the immune responses triggered by clinically tested TLR agonists, glucopyranosyl lipid A (GLA) and CpG. Based on preliminary data, we hypothesize that ADJ is an effective antigen delivery system with immune modulating properties. We further hypothesize that combining ADJ with GLA and CpG constitutes a novel adjuvant that couples the effective antigen delivery and immune modulatory properties of ADJ with the immune potentiating effects of GLA and CpG to concomitantly activate multiple innate signaling pathways. In aim 1, we will test whether the combination adjuvant augments the differentiation and persistence of systemic and mucosal tissue-resident memory CD8 T cells along with antibodies and CD4 T cells. Aim 2 will investigate whether and how the combination adjuvant enhances the process of cross presentation by human and murine DCs in vitro. Mechanisms examined will include antigen uptake and targeting to early endosomes, endosomal acidification and retention of antigen, role of lysosomes and proteasome, antigen presentation to naïve T cells and the signaling pathways engaged. In aim 3, we will determine whether and how the combination adjuvant enhances mechanisms of cross presentation in vivo. The proposed work has the potential to discover a novel combination adjuvant that will engage multiple signaling pathways in immune cells and harness the unique immune stimulating properties of individual components to engender a balanced and durable humoral and CMI response. The findings from this work will be highly significant and expected to have broad impact on the clinical development of effective vaccines against diverse pathogens.