Engineering biosynthesis and incorporation of an immunogenic amino acid

活细菌疫苗可以经过改造，更有效地触发所需的免疫反应，以防止感染。这个项目研究了一种制造更有效的活细菌疫苗的方法，方法是对细菌进行工程，将某些非典型的蛋白质构建块，称为非天然氨基酸(NNAA)，引入他们的蛋白质中。这些NNAA可以帮助刺激针对细菌中通常会逃避免疫反应的蛋白质的免疫反应，从而导致更有效的疫苗。作为这个项目的一部分，本科生将接受指导和资源来进行与非标准氨基酸相关的项目。代谢工程策略将被用来创造形成硝基芳香氨基酸的从头开始的生化途径。作为代谢工程的产物，硝基化学官能团的研究还很少。因此，将对相关硝基化合物的稳定性和毒性进行研究。同时，将检查工程氨酰-tRNA合成酶和tRNA对的底物特异性，以促进这种氨基酸在蛋白质中的模板导向结合。该项目还将研究是否可以在不破坏关键结构特征的情况下将免疫原性氨基酸引入到模型细菌抗原中，以及小鼠免疫系统如何对修饰和未修饰的抗原做出反应。总体而言，该项目将产生基础知识和工具，可能导致代谢工程首次应用于疫苗研究。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Live bacterial vaccines can be engineered to more effectively trigger a desired immune response to prevent infection. This project examines an approach to making more effective live bacterial vaccines by engineering the bacteria to introduce certain atypical protein building blocks, called non-native amino acids (NNAAs), into their proteins. These NNAAs could help stimulate an immune response against proteins in bacteria that would usually evade the immune response, thus leading to more effective vaccines. As part of this project, undergraduate students will receive mentoring and resources to conduct projects related to non-standard amino acids.Metabolic engineering strategies will be utilized to create a de novo biochemical pathway that forms a nitroaromatic amino acid. The nitro chemical functional group has scarcely been explored as a product of metabolic engineering. Therefore, the stability and toxicity of relevant nitro compounds will be explored. In parallel, the substrate specificity of engineered aminoacyl-tRNA synthetase and tRNA pairs will be examined in order to facilitate template-directed incorporation of this amino acid within proteins. This project will also study whether the immunogenic amino acid can be introduced to a model bacterial antigen without disrupting key structural features, and how the mouse immune system responds to the modified and unmodified antigen. Overall, this project will generate foundational knowledge and tools that may lead to the first application of metabolic engineering to vaccine research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.