A subunit Cryptococcus vaccine

项目摘要/摘要 隐球菌病是由被包裹的酵母新生隐球菌和加蒂亚氏杆菌感染而引起的 世界范围内培养阳性脑膜炎的常见原因。辅助性T细胞(Th)对宿主防御至关重要。 该项目的首要目标是亚单位疫苗的临床前进展，以保护处于危险中的人。 预防隐球菌病的人群(如艾滋病毒携带者、移植接受者、流行地区的居民)。我们的工作 假设是利用精心设计的小鼠和人类的研究，我们可以合理地发展一个亚单位 最终用于人体测试的多抗原疫苗。我们进一步假设，鉴于人类的人类白细胞抗原的多样性 隐球菌的种群和多样性，一种成功的人类隐球菌“T细胞疫苗”将 由三种蛋白质抗原和一种有效的Th刺激佐剂组成。目标1.确定 佐剂单抗原候选抗原在小鼠模型中的保护作用 隐球菌病。我们已经鉴定了七种隐球菌蛋白，当它们在E. 并包装成疫苗，极大地保护了两个近亲繁殖的小鼠品系免受原本致命的 挑战新城疫杆菌。我们将评估这些由我们的 主佐剂CAF01，对抗世界各地发现的典型强毒隐球菌株。目标2.剖析 小鼠和人类对候选疫苗抗原的免疫反应。我们将研究体外实验 对候选抗原的免疫反应和免疫系统的手臂在体内的作用。肺召回CD4+ 并将确定小鼠接种和攻击后的CD8+T细胞(包括记忆)反应。 疫苗保护研究将在小鼠有CD4+T细胞受损的条件下进行， 从而对隐球菌病，特别是艾滋病毒的主要人类风险因素进行建模。抗体的作用将是 进行了功能增益和功能损耗实验研究。人CD_4~+和CD_8~+T细胞对 七种候选疫苗抗原将使用来自有无疫苗的受试者的人PBMCs进行比较 隐球菌病。目的3.检测抗原组合的免疫原性和保护性。我们将选择 在这七种抗原中，一种由三种抗原组成的先导疫苗配方在CAF01中得到佐剂。这 目标将通过根据前两个目标的研究确定顶级抗原的优先顺序来实现，然后 在小鼠模型中测试含有抗原组合的疫苗的免疫原性和保护性 隐球菌病。我们预计在授权期结束时，我们将拥有一种亚单位隐球菌疫苗。 为进一步的临床前开发和最终的临床试验做好准备。建议进行的研究 解决全球对开发隐球菌疫苗的主要卫生需求，提供对 隐球菌病的免疫致病机制，并建立适用于其他疫苗的原理证明- 可预防的疾病。

Project Summary/Abstract Cryptococcosis, due to infection by the encapsulated yeast Cryptococcus neoformans and C. gattii, is the most common cause of culture-positive meningitis worldwide. T helper (Th) cells are paramount to host defenses. The overarching goal of this project is the preclinical advancement of a subunit vaccine to protect at risk populations (e.g., HIV+, transplant recipients, residents of endemic areas) from cryptococcosis. Our working hypothesis is using carefully designed mouse and human studies, we can rationally develop a subunit multiantigen vaccine for eventual human testing. We further postulate that given HLA diversity in the human population and diversity amongst cryptococcal strains, a successful human cryptococcal “T cell vaccine” will consist of three protein antigens combined with a potent Th-stimulating adjuvant. Aim 1. Determine the protective efficacy of adjuvanted single antigen candidate antigens using mouse models of cryptococcosis. We have identified seven cryptococcal proteins which, when expressed recombinantly in E. coli and packaged into vaccines, significantly protected two inbred mouse strains against an otherwise lethal challenge with C. neoformans. We will evaluate the protective efficacy of these antigens formulated with our lead adjuvant, CAF01, against representative virulent cryptococcal strains found worldwide. Aim 2. Dissect murine and human immunologic responses to candidate vaccine antigens. We will investigate ex vivo immune responses to candidate antigens and the in vivo role of arms of the immune system. Lung recall CD4+ and CD8+ T cell (including memory) responses following murine vaccination and challenge will be determined. Vaccine protection studies will be undertaken under conditions where mice have CD4+ T cell compromise, thereby modeling the major human risk factors for cryptococcosis, especially HIV. The role of antibody will be studied with gain of function and loss of function experiments. Human CD4+ and CD8+ T cell responses to the seven candidate vaccine antigens will be compared using human PBMCs from subjects with and without cryptococcosis. Aim 3. Test immunogenicity and protection with antigen combinations. We will select from the seven antigens a lead vaccine formulation consisting of three antigens adjuvanted in CAF01. This goal will be accomplished by prioritizing the top antigens based on the studies in the first two aims and then testing vaccines containing antigen combinations for immunogenicity and protection in mouse models of cryptococcosis. We anticipate by the end of the granting period we will have a subunit cryptococcal vaccine ready to be moved forward for further preclinical development and eventual clinical trials. The proposed studies address a major global health need for the development of cryptococcal vaccines, provide insights into the immunopathogenesis of cryptococcosis, and establish proofs of principle applicable to other vaccine- preventable diseases.