Sentinels: Living-Tissue for Doppler Detection of Emerging Microbial Threats

抗生素耐药性可能很快使普通抗生素失效，因此迫切需要寻找新一代抗菌疗法。一种测试抗菌药物的新方法是测量药物对活细胞内微生物的影响。当细胞被微生物感染时，一小群活细胞反射的光可以感知，因为感染改变了内部细胞机制的工作方式。利用细胞群中的自然细胞内运动作为“哨兵”是一种前所未有的检测微生物的新方法。为了进一步的教育目标，细胞运动对反射光的影响将很容易地用简单的激光笔和手机摄像头向高中生演示。为了促进新的抗菌化合物的发现，将开发一种新的基于物理的光学筛选技术来满足这一需求。生物动力多普勒分析（BDP）使用低相干数字全息技术对活组织内的细胞内运动进行多普勒光谱分析。它是一种敏感的探针，可以探测到由药物或组织内感染引起的细胞动力学的细微变化。生物动力学分析已经被用于预测癌症患者对化疗的反应，方法是在活的离体活检上应用癌症药物。在这个项目中，团队将开发多普勒检测活组织哨兵的细菌感染。活体组织哨兵的前提是，在细菌能够直接表征自己之前，哨兵行为被早期感染所改变。在拟议的研究中，微生物入侵的生物动力学分析将沿着以下几条线扩展：1)提高哨兵检测低水平细菌感染的敏感性；2)构建微生物感染哨点反应函数库；3)进行抗生素耐药性定量分析；4)首次检测到组织哨兵的病毒感染，5)开发新的深度学习算法来分类致病性和预测治疗效果。拓展目标是招募本科生参与研究经验，包括研究中代表性不足的群体，并为7-12年级的学生开发动手细胞内运动成像实验。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Antibiotic resistance may soon make common antibiotics ineffective, and there is a pressing need to find new-generation antimicrobial therapies. A novel approach to test antimicrobial drugs is to measure the effect of the drug on the microbes within living cells. Light reflected by small collections of living cells can sense when the cells are infected with microbes because the infection changes how the internal cellular machinery works. The use of natural intracellular motions in cell clusters that act as “sentinels” is an unprecedented new approach to detecting microbes. To further educational goals, the effect of cellular motion on reflected light will be easily demonstrated to high-school students using simple laser pointers and cell phone cameras.To improve the discovery of new antimicrobial compounds, a new physics-based optical screening technology will be developed to fill this need. Biodynamic Doppler profiling (BDP) performs Doppler spectroscopy of intracellular motions inside living tissue using low-coherence digital holography. It is a sensitive probe of the subtle changes of cellular dynamics caused by drugs or infections inside tissue. Biodynamic profiling has already been used to predict the response of cancer patients to chemotherapy by applying cancer drugs on living ex vivo biopsies. In this project the team will develop Doppler detection of bacterial infection of living-tissue sentinels. The premise of living-tissue sentinels is that the sentinel behavior is modified by early infection before the bacteria can be characterized directly themselves. In the proposed research, biodynamic profiling of microbial invasion will be extended along several lines by: 1) enhancing the sensitivity of the sentinels to detect lower-level bacterial infections; 2) assembling a library of sentinel response functions to microbial infection; 3) performing quantitative assays of antibiotic resistance; 4) demonstrating the first detection of viral infections of tissue sentinels, and 5) developing new deep-learning algorithms to classify pathogenicity and predict therapeutic efficacy. The outreach objective is to enlist undergraduates in the research experience, including under-represented groups in research, and developing hands-on intracellular motility imaging experiments for grades 7-12.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.