Lepe Bianca A, Zheng Christine R, Leddy Owen K, Allsup Benjamin L, Solomon Sydney L, Bryson Bryan D
Department of Biological Engineering, MIT, Cambridge, Massachusetts, USA.
Ragon Institute of Mass General, Harvard, and MIT, Cambridge, Massachusetts, USA.
Microbiol Spectr. 2025 Feb 4;13(2):e0227724. doi: 10.1128/spectrum.02277-24. Epub 2024 Dec 17.
Tuberculosis (TB) is the leading cause of infectious disease death and lacks a vaccine capable of protecting adults from pulmonary TB. The bacterial surface is a critical interface that shapes host-pathogen interactions. Several knowledge gaps persist in our understanding of (Mtb)-host interactions that may be addressed by an improved understanding of the Mtb surface proteome, including the identification of novel vaccine targets as well as developing new approaches to interrogate host-pathogen interactions. Here, we sought to expand our understanding of the Mtb surface proteome in service of these knowledge gaps by adapting protease shaving protocols for multiplexed quantitative mass spectrometry. Pairing quantitative mass spectrometry with the construction of validation strains, we revealed several novel Mtb proteins on the Mtb surface largely derived from the PE/PPE class of Mtb proteins, including PPE18, a component of a leading Mtb vaccine candidate. We next exploited the localization of PPE18 to decorate the Mtb surface with heterologous proteins. Together, these studies reveal potential novel targets for new Mtb vaccines as well as facilitate new approaches to study difficult-to-study cellular compartments during bacterial growth and infection.IMPORTANCEThe surface of a bacterial pathogen is a critical interface between the bacterium and the immune system. A better understanding of this interface would facilitate the discovery of new vaccine targets, new virulence proteins, and enable new technologies that modify the bacterial surface. In this study, we established a multiplexed and quantitative biochemical strategy to study the surface of (Mtb) and identified new vaccine targets. We furthermore established design rules for new technologies aimed at modifying the composition of the bacterial surface. Specifically, we achieved a biological milestone that has not been rigorously reported previously, which is the successful modification of the Mtb surface with a non-native protein.
结核病（TB）是传染病死亡的主要原因，且缺乏能够保护成年人免受肺结核侵害的疫苗。细菌表面是塑造宿主-病原体相互作用的关键界面。在我们对结核分枝杆菌（Mtb）-宿主相互作用的理解中，仍存在一些知识空白，而对Mtb表面蛋白质组的深入了解可能有助于填补这些空白，包括识别新的疫苗靶点以及开发研究宿主-病原体相互作用的新方法。在此，我们试图通过采用蛋白酶刮削方案用于多重定量质谱分析，来扩展我们对Mtb表面蛋白质组的理解，以填补这些知识空白。将定量质谱分析与验证菌株的构建相结合，我们在Mtb表面发现了几种新的Mtb蛋白，这些蛋白主要来源于Mtb的PE/PPE蛋白家族，包括PPE18，它是一种主要的Mtb疫苗候选成分。接下来，我们利用PPE18的定位，用异源蛋白修饰Mtb表面。这些研究共同揭示了新型Mtb疫苗的潜在新靶点，并为研究细菌生长和感染过程中难以研究的细胞区室提供了新方法。重要性细菌病原体的表面是细菌与免疫系统之间的关键界面。更好地理解这个界面将有助于发现新的疫苗靶点、新的毒力蛋白，并催生修饰细菌表面的新技术。在本研究中，我们建立了一种多重定量生化策略来研究Mtb的表面，并确定了新的疫苗靶点。此外，我们还为旨在改变细菌表面组成的新技术制定了设计规则。具体而言，我们实现了一个此前未被严格报道过的生物学里程碑，即成功地用一种非天然蛋白质修饰了Mtb表面。
