EAGER: NSF-BSF: Quorum Biosensing Using Magnetic Field-Activated Molecular Machines

EAGER：NSF-BSF：使用磁场激活分子机器进行群体生物传感

• 批准号: 1939063
• 负责人: Evgeny Katz
• 金额: $ 15万
• 依托单位: Clarkson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-15 至 2023-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1939063&HistoricalAwards=false
• 关键词: EAGER; NSF; BSF; Quorum; Biosensing

Communication of bacterial cells to each other, called quorum sensing, is an important mechanism to control their population. By "talking" to each other with chemical signals, bacterial cells can decide if the present conditions are favorable for their multiplication and formation of biofilms. Detection and inhibition of the quorum sensing provides novel possibilities for treating bacterial infections with theranostics (combination of diagnostics and therapy). This EAGER project addresses fundamental aspects of the quorum sensing analysis and its inhibition based on a nano-technological approach using molecular "machines" assembled on magnetic nanoparticles and activated at a distance with an external magnetic field. Success will open future biomedical applications and other potential applications in environmental studies (e.g., for the analysis and enhancement of water remediation efficiency) and homeland security (such as preventing bioterrorism).Quorum sensing is a mechanism of gene regulation triggered by small molecules sensed by bacteria in order to control the density of bacterial population depending on available resources. Disruption of this mechanism using small molecules is a novel strategy to combat pathogenic bacteria. The importance and advantage of identifying such potential drugs is that by signaling bacteria with "disinformation", bacteria are not threatened, hence have no incentive to develop resistance to the drug (unlike with conventional antibiotics). Thus, these drugs are expected to be in the forefront of antibacterial treatments, when antibiotics could not be used anymore. The proposed research program will make use of a novel class of Magnetic Field-activated Molecular Machines that will be developed within the project framework. These new machines will be used as unique biosensor devices that will enter the cells and will report (upon magnetic stimulation) on the concentration of different genes in their transcribed form (mRNA) that are in charge of sensing between bacteria. The reporting signal will be fluorescent and will be quantified. The fluorescent signal will be an indication of the quantities of mRNA molecules that exist in the cells. This approach can be taken both for the quantification of multiple genes, but also for the screening of potential drugs (out of potential drug libraries) that inhibit the sensing of small molecules between bacteria. Since in vivo quantification of mRNA is considered a realistic representation of the state of cells at a given time point, this approach can be expected to be highly productive in the analysis of quorum sensing in bacteria and then its inhibition. The expected results will include novel quorum sensing inhibitors that may be used as new antibacterial reagents to fight Pseudomonas aeruginosa related infections (in the future other bacterial infections). Specific objectives include: (i) a proof of concept that the molecular machines described can enter bacterial cells and detect mRNAs, (ii) specific detection of mRNAs and their quantification, (iii) biosensing of low concentrations of mRNAs upon down regulation of quorum sensing in the presence of inhibitors, (iv) and the use of these molecular machines in high-throughput screens of quorum sensing inhibitors operating as novel anti-bacterial drugs.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.

细菌细胞之间的交流被称为群体感应，是控制细菌数量的重要机制。细菌细胞通过化学信号相互“对话”，就可以决定目前的条件是否有利于它们的繁殖和生物膜的形成。群体感应的检测和抑制为治疗细菌感染提供了新的可能性(诊断和治疗相结合)。这个急切的项目解决了基于纳米技术方法的群体感应分析及其抑制的基本方面，该方法使用组装在磁性纳米颗粒上的分子“机器”，并在与外部磁场相距较远的地方激活。成功将开启未来的生物医学应用和其他潜在的环境研究(例如，分析和提高水修复效率)和国土安全(如防止生物恐怖主义)的应用。群体感应是一种由细菌感应的小分子触发的基因调控机制，以控制依赖于可用资源的细菌种群密度。使用小分子破坏这一机制是对抗病原菌的一种新策略。识别这种潜在药物的重要性和优势在于，通过向细菌发出“虚假信息”的信号，细菌不会受到威胁，因此没有诱因对药物产生抗药性(与传统抗生素不同)。因此，当抗生素不能再使用时，这些药物有望走在抗菌治疗的前列。拟议的研究计划将利用将在项目框架内开发的一类新型磁场激活分子机器。这些新机器将被用作独特的生物传感器设备，它们将进入细胞，并(在磁刺激下)报告负责在细菌之间感应的不同基因转录形式(MRNA)的浓度。报告信号将是荧光的，并将被量化。荧光信号将指示存在于细胞中的信使核糖核酸分子的数量。这种方法既可用于多个基因的量化，也可用于(从潜在药物库中)筛选抑制细菌之间小分子传感的潜在药物。由于在体内对mRNA的量化被认为是给定时间点细胞状态的真实表示，因此这种方法有望在分析细菌的群体感应及其抑制方面具有很高的生产力。预期的结果将包括新的群体感应抑制剂，可能被用作新的抗菌试剂，以对抗铜绿假单胞菌相关感染(未来其他细菌感染)。具体目标包括：(I)证明所描述的分子机器可以进入细菌细胞并检测mRNAs，(Ii)mRNAs的特定检测及其量化，(Iii)在抑制剂存在的情况下下调群体感应时对低浓度mRNAs的生物传感，(Iv)以及在作为新型抗菌药物作用的群体感应抑制剂的高通量筛选中使用这些分子机器。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。