JAN 08, 2018 02:01 PM PST

Scientists Identify Link Between Zika Virus and Pregnancy Complications

WRITTEN BY: Kara Marker

The Zika virus is notorious for its deleterious effects on pregnancy, whether through causing miscarriages or birth defects. Now from the Howard Hughes Medical Institute, scientists uncover exactly what happens in a host infected by the Zika virus that ultimately results in a terminated pregnancy.

When human placental tissue (fluorescence microscopy image shown) is exposed to interferon-β, it develops syncytial knots. Credit: Yockey et al., Science Immunology (2018)

On trial in a new Science Immunology study is an interferon receptor responsible for binding two types of interferons, alpha and beta. Interferons are produced by the immune system in response to pathogenic invasions, and they contribute toward triggering an appropriate immune response. The interferon receptor under study is potentially responsible for “deciding” whether or not to end a pregnancy when the host is infected with the Zika virus, but it is also involved in non-Zika pregnancy complications and miscarriages.

"Our work shows how this [interferon] signaling pathway works to terminate pregnancies that are not going to be viable early on,” explained study author Akiko Iwasaki.

The study focused on comparing pregnant female mice who had the interferon receptor and pregnant female mice who did not. Those lacking the interferon receptor had higher virus levels, as expected, but developing fetuses from mice mothers with the receptor did not survive past early pregnancy. Iwasaki and the other researchers suspect that this was due to underdeveloped blood vessels, an “abnormal barrier” between fetus and mother, and cellular stress.

How does the interferon receptor make the difference between life and death for the fetus? Iwasaki says it acts as a “checkpoint,” signaling termination of a pregnancy if it detects interferons - a sign of Zika infection. As opposed to the Zika virus directly impacting the fate of a pregnancy, it is the host’s immune response that ultimately “makes the decision.”

It is unknown if the same process occurs in pregnant women infected with Zika virus.

The same research team did, however, also conduct a study of the impact of interferons on human placenta tissue in the lab. The found that the tissue developed “abnormal knot structures” in response to interferon-beta. Interferon signaling has also been connected to poor pregnancy outcomes in past studies.

In the future, researchers from the present study plan on studying interferon levels at different stages of pregnancy, which could potentially help identify when a pregnant woman is most at risk of her baby developing microcephaly or other Zika-related complications.

The Zika virus is spread by two mosquito species, Aedes aegypti and Aedes albopictus. Infection with Zika virus during pregnancy has been shown in many studies to cause birth defects. An infection with the Zika virus often goes unnoticed, but when those affected do experience symptoms, fever, rash, headache, and muscle pain is common. People usually don’t die from a Zika virus infection.

Sources: Centers for Disease Control and Prevention, Howard Hughes Medical Institute

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
MAY 03, 2018
Cardiology
MAY 03, 2018
Immune Cells and Heart Disease: Helpful or Harmful?
Depending on where an immune cell is during injury to the heart, like during a heart attack, their activity can either be harmful or helpful. From Case Wes...
MAY 16, 2018
Immunology
MAY 16, 2018
Antibodies Neutralize Two Different Hemorrhagic Fever Viruses
Scientists have found evidence for potential antibody-based therapeutics to treat more than one hemorrhagic fever virus at once. From Harvard Medical Schoo...
MAY 17, 2018
Immunology
MAY 17, 2018
Epigenetic Similarities Between Rheumatoid Arthritis and Huntington's Disease
A detailed investigation into the epigenome of rheumatoid arthritis (RA) patients revealed unexpected similarities between RA and Huntington’s diseas...
JUN 30, 2018
Immunology
JUN 30, 2018
CD4 T Cells Responsible for Inflammatory Bowel Disease
A specific subset of immune cells could be targeted to better treat inflammatory bowel disease (IBD). A new University of Alabama at Birmingham study point...
AUG 10, 2018
Immunology
AUG 10, 2018
Cancer Cell 'Drones' Battle Immune System
Cancer cells release PD-L1 containing exosomes that circulate in the blood and stop T cells before they can reach tumors....
SEP 11, 2018
Cannabis Sciences
SEP 11, 2018
The Potential Anti-cancer Effects of Cannabinoids
They're known for helping to reduce the impact of cancer drug side effects, but it's possible that cannabinoids themselves are cancer fighters....
Loading Comments...