A nanoparticle-based vaccine against leishmaniasis

描述(申请人提供)：我们建议开发一种针对皮肤利什曼病的重组亚单位疫苗。该疫苗将包含两种蛋白质抗原，TSA/Tryp和P-4。这两种抗原在利什曼原虫物种中高度保守，可被人类患者的T细胞识别，并在小鼠模型研究中提供对活体挑战的保护。我们预计，使用PLGA纳米颗粒和这两种蛋白一起进行免疫将对许多利什曼原虫引起的疾病产生保护作用。重组表达的TSA/Tryp和P-4蛋白将被制成含有两种佐剂之一的PLGA纳米颗粒，即CpG寡核苷酸和/或单磷脂A(MPLA)。将评估不同的配方对小鼠的免疫原性和免疫反应(记忆)的持续时间。我们预计，包裹在PLGA颗粒中的蛋白质将引发持久的免疫反应。对利什曼病的保护主要是由T细胞介导的，特别是对IL-2、TNFpha和干扰素-γ双阳性或三阳性的CD4+/CD8+T细胞。我们将选择两种配方来激发应答比例最高的CD4/CD8 T细胞。这两种制剂随后将在两种利什曼病小鼠模型上进行疗效测试。第一种模式是对大型利什曼原虫的挑战，大型利什曼原虫是东半球利什曼病的主要病种。第二种模式是感染泛美志贺氏菌，这是一种新世界利什曼病的模式，可能是对疫苗效力进行更严格的测试。在该项目的第二阶段，我们预计将在利什曼病的非人类灵长类动物模型中测试最有希望的配方的有效性。

DESCRIPTION (provided by applicant): We propose to develop a recombinant subunit vaccine against cutaneous leishmaniasis. This vaccine will incorporate two protein antigens, TSA/TryP and P-4. Both antigens are highly conserved among Leishmania species, are recognized by T cells of human patients, and confer protection against a live challenge in murine model studies. We expect that immunization using PLGA nanoparticles together with these two proteins will confer protection against disease caused by many of the Leishmania species. Recombinantly expressed TSA/TryP and P-4 proteins will be formulated into PLGA nanoparticles containing one of two adjuvants, namely a CpG oligonucleotide and/or monophosphoryl lipid A (MPLA). Different formulations will be evaluated for immunogenicity and duration of the immune response (memory) in mice. We expect that proteins encapsulated in PLGA particles will elicit long-lasting immune responses. Protection against Leishmania has been shown to be mediated primarily by T-cells, and in particular CD4+/CD8+ T-cells double-positive or triple-positive for IL-2, TNFalpha, and IFN-gamma. We will select the two formulations eliciting the highest proportion responding CD4/CD8 T cells. These two formulations will then be tested for efficacy in two murine models of leishmaniasis. The first model is a challenge with L. major, the main species responsible for leishmaniasis in the Old World. The second model is an infection with L. (Viannia) panamensis, a model for New World leishmaniasis and possibly a more stringent test of vaccine efficacy. In Phase II of this project, we anticipate testing the efficacy of the most promising formulation in non-human primate models of leishmaniasis.