Picture an intelligence officer in the field. She is trying to piece together a suspected threat and has access to someone who may have a role in carrying it out. There may be traces of biological or chemical agents on his clothing or hair. She can look for them, but they're transient, and often present in such low concentrations that she'll need to send samples to a laboratory. Or she can check his epigenetic markers, read a history of any time he's been exposed to threat agents, and start piecing together a chain of evidence right there in the field, in real time.
DARPA's new Epigenetic CHaracterization and Observation (ECHO) program aims to build a field-deployable platform technology that quickly reads someone's epigenome and identifies signatures that indicate whether that person has ever — in his or her lifetime — been exposed to materials that could be associated with weapons of mass destruction (WMD).
The epigenome is biology's record keeper. Though DNA does not change over a single lifetime, a person's environment may leave marks on the DNA that modify how that individual's genes are expressed. This is one way that people can adapt and survive in changing conditions, and the epigenome is the combination of all of these modifications. Though modifications can register within seconds to minutes, they imprint the epigenome for decades, leaving a time-stamped biography of an individual's exposures that is difficult to deliberately alter.
Whereas current forensic and diagnostic screening technologies only detect the immediate presence of contaminants, the envisioned ECHO technology would read someone's epigenome from a biological sample, such as a finger prick or nasal swab, to reveal possible exposure to WMD or WMD precursors, even when other physical evidence has been erased.
"The human body registers exposures and logs them in the epigenome," explained Eric Van Gieson, the ECHO program manager. "We are just beginning to understand this rich biographical record that we carry around with us. We hope that with the capabilities developed within ECHO, someone in the field will immediately know if a suspected adversary has handled or been exposed to threat agents. The same technology could also serve as a diagnostic tool for our own troops, to diagnose infectious disease or reveal exposure to threat agents, so that medical countermeasures can be applied in time to make a difference."
Researchers on the four-year ECHO program will have two primary challenges: to identify and discriminate epigenetic signatures created by exposure to threat agents; and to create technology that performs highly specific forensic and diagnostic analyses to reveal the exact type and time of exposure. To develop this capability, researchers will have to assemble a foundational training dataset of pre- and post-exposure epigenetic readouts in biological samples. They will also have to create a device capable of performing multiple molecular analyses and onboard bioinformatics in 30 minutes or less, compared to an average of two days using current lab-centered processes. By the end of the effort, DARPA's goal is to deliver ECHO capability in a man-portable device that can be used by an operator with minimal training.
"ECHO technology could open up new sources of forensic evidence and make battlefield collection of evidence safer, more efficient, and more accurate," said Van Gieson. "Additionally, by making it possible to deploy an analytical capability to vastly more locations, we would enhance our ability to conduct global, near-real-time surveillance of emerging threats."
ECHO is focused specifically on diminishing the threat posed by WMD and improving diagnostics for troops who may have been exposed to threat agents. The ability to partially reconstruct an individual's history through analysis of the epigenome, however, could have application well beyond national security and thus raise privacy concerns. Accordingly, DARPA intends to proactively engage with several independent ethical and legal experts to help inform the Agency's research plans, think through potential issues, and foster broader dialogue in the scientific community on social implications.
DARPA will host a Proposers Day on Feb. 23, 2018, in Arlington, Virginia, to explain the ECHO program to potential proposers and answer questions. Details and registration are available at: https://www.fbo.gov/spg/ODA/DARPA/CMO/DARPA-SN-18-23/listing.html.