Biological weapons achieve their intended effects by infecting people with disease-causing microorganisms and other replicative entities, including viruses, infectious nucleic acids and prions. The chief characteristic of biological agents is their ability to multiply in a host over time.
Viral pathogens pose a continuous and shifting biological threat to military readiness and national security overall in the form of infectious disease with pandemic potential. Today’s limited vaccines and other antivirals are often circumvented by quickly mutating viruses that evolve to develop resistance to treatments that are carefully formulated to act only specific strains of a virus. DARPA’s INTERfering and Co-Evolving Prevention and Therapy (INTERCEPT) program aims to harness viral evolution to create a novel, adaptive form of medical countermeasure—therapeutic interfering particles (TIPs)—that outcompetes viruses in the body to prevent or treat infection.
DARPA BTO’s Rapid Threat Assessment program, aims to develop methods and technologies that can map the complete molecular mechanism of a threat agent within 30 days of its exposure to a human cell. DARPA is now developing new approaches to fight Biological attacks.
DARPA plans to develop soldier cells to fight biological attack
DARPA has awarded four-year, $US5.7 ($8) million grant to Johns Hopkins University, with the aims to create a bio-control system able to deploy single-cell fighters that will hunt down specific pathogens and destroy their lethality.
Researchers will start with two forms of bacteria. Legionella, a kind of bacteria that causes Legionnaire’s disease and Pseudomonas aeruginosa, which is the second-leading cause of infections in hospitals, according to Johns Hopkins University. If the tests conducted during the grant period prove successful, it is envisioned that these disease-fighting cells could be used to clean contaminated soil and defend against a bio-weapon attack.
What makes this bio-control system unique is that each engineered cell must seek and destroy dangerous bacteria without the help of a human controlling them:
Genetically modified red blood cells (RBC)
Scientists from the Whitehead Institute for Biomedical Research, under new research sponsored by DARPA, have demonstrated genetically modified red blood cells (RBC) in mice to successfully carry drugs or vaccines to specific sites throughout the body.
Their approach called sortagging, used “bacterial enzyme sortase A” to bind between the surface protein and “small-molecule therapeutic or an antibody capable of binding a toxin”, while leaving the cells unharmed. DARPA hopes that through blood transfusion, long-lasting reserves of antitoxin antibodies can be built in the body that can provide long term protection to soldiers against biological toxins deployed against them.
DARPA’s Rapid threat assessment
Novel chemical and biological weapons have historically been mass-produced within a year of discovery. Using current methods and technologies, researchers would require decades of study to gain a cellular-level understanding of how new threat agents exert their effects. This temporal gap between threat emergence, mechanistic understanding and potential treatment leaves U.S. forces vulnerable.
DARPA launched the Rapid Threat Assessment (RTA) program with an aggressive goal for researchers: develop methods and technologies that can, within 30 days of exposure to a human cell, map the complete molecular mechanism through which a threat agent alters cellular processes.
Threat agents, drugs, chemicals and biologics interfere with normal cell function by interacting with one or more molecules associated with the cell membrane, cytoplasm or nucleus. Since a human cell may contain up to 30,000 different molecules functioning together in complex, dynamic networks, the molecular mechanism of a given threat agent might involve hundreds of molecules and interactions.
Performers on RTA will seek to develop tools and methods to detect and identify the cellular components and mechanistic events that take place over a range of times, from the milliseconds immediately following threat agent exposure, to the days over which alterations in gene and protein expression might occur. The molecular mechanism must also account for molecular translocations and interactions that cross the cell membrane, cytoplasm and nucleus.
Understanding the molecular mechanism of a given threat agent would provide researchers the framework with which to develop medical countermeasures and mitigate threats. If RTA is successful, potential adversaries will have to reassess the cost-benefit analysis of using chemical or biological weapons against U.S. forces that have credible medical defenses.
Successful RTA technologies would also be readily applicable to drug development and combating emerging diseases. In both cases, detailed knowledge of the molecular mechanism is one of the ingredients that will enable new drugs to win approval by shortening the evaluation of drug efficacy and toxicity.
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