ABSTRACT With escalating challenges of climate change and social inequality, there is an urgent need for tools that can monitor the influences of the exposome on human health across large populations. Due to the heterogeneity and complexity of biological responses in the body, the capacity to obtain organ-level insights from a simple blood draw is much desired. Extracellular vesicles (EVs) are bilayer membrane structures of diameters 30 – 1000 nm, and they are released into the bloodstream by cells throughout the body, at concentrations on the order of 1010 per ml. Their molecular content of proteins, dsDNA oligomers, microRNAs, mRNAs, and other analytes, may play multiple functional roles via EV trafficking, and may also provide a diagnostic report back on the tissue of origin. As such, EVs provide a unique opportunity to study the health impact of environmental exposures through blood analyses. The long-term goal of this proposed program is to conduct population-level exposomic surveillance through the development of a minimally invasive method that can provide a systems view of health status. The method will be capable of monitoring tissue-specific signatures across individual organs and organ systems through measurements of circulating EVs. The overall objective of this project is to develop, validate, and apply the analytical infrastructures (technologies, software, and resources) that powers the method, focusing on investigating the environmental impact on the human lungs as a proof-of-concept. To establish the technological foundation of this project, we will integrate an exciting technology trio collectively termed the Extracellular Vesicle Tricorder. The first technology, VET-seq (Vesicle Epitope Transcript Sequencing), is a droplet-based sequencing method that resolves the organ source of circulating EVs by detecting EV proteins and RNA cargoes simultaneously at single-vesicle resolution. The second technology, OrganView, aims to sort and assemble scrappy information carried by EVs into meaningful biological messages with organ specificity. The third technology, VPU (Vesicle Processing Unit), integrates a sensitive nanoparticle method, digital microfluidics, and on-chip immunoassay, to facilitate population-level analysis of EVs. Towards these challenging goals, I have assembled a multidisciplinary research team to bring together complementary expertise in micro-nanotechnologies, molecular epidemiology, EV biology, bioinformatics and statistical modeling, lung cancer, and infectious diseases. The proposed research is highly innovative because it harnesses an emerging class of analytes (EV omics) to develop an unconventional systems approach for monitoring the influence of environmental exposures on human health. Overall, the new concepts, technologies, and resources derived from this work will augment current methods for exposome research, with the potential to deepen our understanding of human exposome and reveal unknown health threats in our environment.

PROJECT NARRATIVE Extracellular vesicles (EVs) are shed into the bloodstream by all cells in the body, providing a unique opportunity to monitor the health impact of environmental exposures through liquid biopsies. Here we propose a technology framework integrating bulk and single EV omics, nanotechnologies, and microtechnologies to extract the blood fingerprints of organ-specific biological responses to life course experiences. The proposed methodologies, technologies, as well as data sets, will be of high value to both basic and translational research communities.