SOURCE: “DESIGNER DNA ARCHITECTURE OFFERS PRECISE AND MULTIVALENT SPATIAL PATTERN-RECOGNITION
FOR VIRAL SENSING AND INHIBITION,” BY PAUL S. KWON ET AL., IN
NATURE CHEMISTRY,VOL. 12; JANUARY 2020BIOMEDICAL SCIENCEDNA Trap
A new test clings to dengue virus
Scientists have crafted a trap for the den-
gue virus using a scaffold made from frag-
ments of DNA. The star-shaped structure
is engineered to single out the virus in the
bloodstream and latch on to it with preci-
sion, providing a power ful yet simple test to
detect the mosquito-transmitted disease.
Dengue is the world’s fastest-growing
vector-borne disease, with multiple serious
outbreaks in 2019. In its severe forms, it can
cause internal bleeding and is sometimes
fatal. There is no widely accepted vaccine
or targeted treatment for dengue, so accu-
rate early detection is crucial.
The spherical surface of the dengue virus
is peppered with antigens, special proteins
the virus uses to attach to the cells it infects.
Scientists led by Xing Wang, a biochemist
at the University of Illinois at Urbana-
Champaign, constructed a flexible scaffold
using DNA nanotechnology to mirror the
proteins’ arrangement on a hemisphere of
the viral surface. The tips and vertices of
this five-pointed “DNA star” align with the
antigens and carry molecules that they
glom on to. The multiple attachment points
make the binding strong and very precise,
the researchers say: the DNA star targets
only viruses with that particular pattern.
Once binding occurs, the star fluoresces, or
lights up, signaling the presence of the virus.
“This is a great example of how DNA
nanotechnology can solve real biological
problems,” says Mingxu You, who leads anucleic acid chemistry research group at
the University of Massachusetts Amherst
and was not involved in the study. “Com-
pared with current [dengue-detection]
techniques, this DNA probe exhibits excit-
ing sensitivity and simplicity.”
Current gold-standard dengue tests
require sophisticated laboratory set-ups
and training. “Our technology is ver y sim-
ple; we need only one to two minutes, and
the cost is only 50 cents for each test,”
Wang says. In their Nature Chemistry pa-
per, published in January, the researchers
compare their technology with current
clinical tests and make a case for its supe-
rior sensitivity and accuracy. It should work
before symptoms appear, and the DNA
nanostructures are nontoxic and friendly
to human tissue, the researchers say.
Dengue’s surface pattern is complex,
Wang adds, so DNA nanostructures must
be molded into complicated geometric
shapes to match. Simpler viruses would
require simpler designs.
Wang is now collaborating with
Sherwood Yao, CEO of Atom Bioworks
in Nor th C arolina, to expand the same
principle to other viruses such as Zika
and influenza—and beyond, to bacteria
and perhaps even cancer cells. Yao has
a background in AI and was intrigued
by the method’s pattern-recognition ap -
proach, which he compared with facial-
recognition techniques. The technology
provides “a programmable interface into
biology,” Yao says. “Our solution could
become a fundamental vehicle not only
to detect a pathogen but also to inhibit it.”
— Harini BarathDNA framework Fluorescing
chemicalDengue virus
Antigen clusterAntigen siteResearchers built a framework from DNA that binds to particular proteins the dengue
virus uses to snag host cells. The framework ( dark blue ) lights up once attached.Illustration by Tami TolpaIn
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