Collaborative Development of a Vaccine against Cutaneous and Visceral Leishmanias

描述(申请人提供)：利什曼原虫是一种原生动物寄生虫，可在亚热带和热带地区导致严重和令人衰弱的疾病。目前还没有有效的疫苗可用，而且由于药物毒性、耐药性的产生、难以获得医疗保健和费用的原因，化疗是有问题的。利什曼原虫疫苗开发面临的挑战包括确定对不同种类和临床形式的利什曼病交叉保护的抗原，以及确定诱导免疫保护的最佳路线和疫苗配方。这一申请代表了三个实验室之间的合作努力，这些实验室致力于开发针对利什曼病的疫苗这一统一主题。剑桥大学的Jenefer Blackwell博士的实验室使用DNA疫苗对小鼠进行了筛选，筛选出100个独特的利什曼原虫基因作为疫苗候选，以对抗大剂量的大毒力利什曼原虫感染。共鉴定出14种新的、可重复使用的保护性抗原。艾奥瓦大学的威尔逊博士的实验室通过免疫血清和T细胞的cDNA文库筛选，发现了六种新的抗原。麦克马洪-普雷特博士在耶鲁大学的实验室已经确定了四种抗原，并对它们进行了表征，以防止亚马逊乳杆菌和/或婴儿乳杆菌的感染。这总共产生了24种可能具有保护性的新型抗原，可以对亚单位疫苗做出贡献。在抗原进入犬和/或人体试验之前，仍有几个问题需要解决，并已形成本项目的三个具体目标：(1)使用GMP标准的DNA疫苗在标准化条件下重新筛选来自三个合作实验室的24种候选疫苗进行保护/交叉保护，并将排名前6-10的疫苗作为最高6价DNA疫苗进行测试；(2)使用两种特性良好的抗原(Tryp和Lack)进一步评估添加DNA启动佐剂是否改善了标准化条件下针对不同种类/临床形式的利什曼病的DNA/MVA Prime-Boost疫苗接种；(3)为可用于犬、灵长类和人类临床试验的多价交叉保护性异种强化疫苗选择最佳的抗原和递送系统组合。通过三个实验室的协调方法，我们将系统地对几种利什曼原虫进行临床前测试，目标是开发泛利什曼原虫保护性疫苗。

DESCRIPTION (provided by applicant): Leishmania are protozoan parasites that can lead to severe and debilitating disease in sub-tropical and tropical regions. There are no effective vaccines available, and chemotherapy is problematic because of drug toxicity, the development of resistance, poor access to medical care, and expense. Challenges facing Leishmania vaccine development include identification of antigens that cross-protect against the different species and clinical forms of leishmaniasis, and identification of the optimal route and formulation of vaccines to induce immune protection. This application represents a collaborative effort between three laboratories working on the unified theme of vaccine development against leishmaniasis. Dr. Jenefer Blackwell's lab at the University of Cambridge has used DNA vaccination in mice to screen 100 unique Leishmania genes as vaccine candidates against high dose virulent L. major infection. Fourteen novel and reproducibly protective antigens were identified. Dr. Wilson's lab at the University of Iowa has discovered six novel antigens through cDNA library screening with immune serum and T cells. Dr. McMahon-Pratt's lab at Yale University has identified four antigens and characterized them for protection against L. amazonensis and/or L. infantum infection. This yields a total of 24 potentially protective novel antigens that can contribute to a subunit vaccine. Before antigens can be taken forward into canine and/or human trials, several issues remain to be addressed, and have been formulated into the three specific aims of this project: (1) To re-screen the 24 candidate vaccines from the three collaborating laboratories for protection/ cross-protection under standardized conditions using DNA vaccines made to GMP standards, and to test the top 6-10 vaccines as up to 6-valent DNA vaccines; (2) To use two well characterized antigens (TryP and LACK) to further evaluate whether the addition of adjuvants with DNA priming improves DNA/MVA prime-boost vaccination against different species/clinical forms of leishmaniasis under standardized conditions; and (3) To choose the best combination of antigens and delivery system for a multi-valent cross-protective heterologous prime- boost vaccine that can be taken forward into canine, primate and human clinical trials. Through a coordinated approach in the three laboratories, we will systematically perform pre-clinical testing against several Leishmania species, with the goal of developing a pan-leishmania protective vaccine.