Zika virus damages placenta, which may explain malformed babies

January 18, 2018 by Franny White, Oregon Health & Science University
This artist's image of a placenta shows how the Zika virus can affect a mother's womb. The maternal blood vessels that feed into the placenta (A) become narrower and limit blood flow to the fetus. The leaf-like villi (C) that enable a fetus to receive oxygen-rich blood, absorb nutrients, and remove waste also become damaged. Seen under here under a microscope (D), representative cells that make up a placenta's fetal villi also become damaged when a pregnant mother becomes infected with Zika. Credit: OHSU

Though the Zika virus is widely known for a recent outbreak that caused children to be born with microencephaly, or having a small head, and other malformations, scientists have struggled to explain how the virus affects a baby as it grows in the womb.

Now, new research suggests the damages a pregnant mother's placenta, an organ inside a woman's uterus that helps protect and care for a growing baby. A paper published in Nature Communications describes how Zika virus infection in five pregnant rhesus monkeys caused placental tissues to become thickened and inflamed.

As a result, the researchers saw less oxygen being transported across the placenta and to the baby. Decreased oxygen levels in a placenta can impair fetal development and ultimately the health of a baby after its born.

"The role of a placenta is to protect and provide nutrition to a growing baby for optimum health," said one of the paper's corresponding authors, Antonio Frias, M.D., an obstetrician and gynecologist at Oregon Health & Science University. "It's concerning how much damage the Zika virus can do to a placenta."

The paper's two other corresponding authors are associate professor Daniel Streblow, Ph.D., and assistant professor Alec Hirsch, Ph.D., both of whom lead molecular microbiology and immunology research at the OHSU Vaccine and Gene Therapy Institute. Streblow also leads pathobiology and immunology research at the Oregon National Primate Research Center and is a professor of and immunology within the OHSU School of Medicine.

The reseachers used a non-invasive, in vivo MRI technique to evaluate inside the placenta and oxygen flow between mother and baby. They found that, in monkeys that were infected with Zika early in their pregnancies, the rate of oxygen transport through the decreased about 10-fold.

The OHSU research team also determined the Zika virus can readily pass from mother to baby and remain in the baby long-term, leading to a chronic infection in utero. These findings may provide important insights into the mechanisms by which Zika virus causes disease during pregnancy.

By better understanding how both mother and child become infected with and affected by the Zika virus, researchers can determine how to prevent its infection and disease. The OHSU research team is using the knowledge gained from this study to help develop a safe and effective Zika vaccine for use during pregnancy.

Explore further: Zika vaccine protects fetus against infection and birth defects

More information: Alec J. Hirsch et al, Zika virus infection in pregnant rhesus macaques causes placental dysfunction and immunopathology, Nature Communications (2018). DOI: 10.1038/s41467-017-02499-9

Related Stories

Zika vaccine protects fetus against infection and birth defects

July 13, 2017
Immunizing female mice with a Zika vaccine can protect their developing fetus from infection and birth defects during pregnancy, according to new research from The University of Texas Medical Branch at Galveston. The findings ...

Study identifies how Zika virus infects the placenta

August 18, 2016
In a new study, Yale researchers demonstrate Zika virus infection of cells derived from human placentas. The research provides insight into how Zika virus may be transmitted from expectant mother to fetus, resulting in infection ...

Scientists track Zika virus transmission in mice

August 3, 2017
National Institutes of Health (NIH) scientists have developed a mouse model to study Zika virus transmitted sexually from males to females, as well as vertically from a pregnant female to her fetus. They are using the model ...

Doctors develop new way to use MRI to predict pregnancy complications

December 6, 2017
UCLA scientists have developed a new way to use magnetic resonance imaging, or MRI, to scan the placenta. The noninvasive approach offers valuable insights into how the mother's blood enters the placenta and sustains the ...

Research provides clues to how Zika virus breaches the placental barrier

September 15, 2016
New research reveals that in pregnant women, Zika virus infection damages certain cells that affect placental formation and function. Furthermore, herpes simplex virus-2 (HSV-2) infection augments placental sensitivity to ...

Researchers hone in on when, where Zika virus attacks

March 9, 2017
The Zika virus attacks tissues in the nervous system, male and female reproductive and urinary tracts, muscles, joints and lymph nodes, and persists for at least 35 days, according to a study conducted in a nonhuman primate ...

Recommended for you

New method may allow country-level real-time surveillance of drug-resistant tuberculosis

August 21, 2018
Global tuberculosis control and elimination will require detailed real-time information on the location of individuals with the disease, the presence of drug resistance, and the patterns of transmission. The surveys currently ...

Lower-risk malaria regions are breeding grounds for drug-resistant strains

August 21, 2018
New drug-resistant strains of the parasite that causes malaria tend to evolve in regions with a lower risk of malaria. This is because in hard-hit areas with high transmission rates, like sub-Saharan Africa, they get outcompeted ...

Clay fights MRSA, other superbugs in wounds

August 21, 2018
The use of mud or wet clay as a topical skin treatment, or poultice, is a common practice in many cultures. In fact, the concept of using mud as medicine goes back to the earliest times.

Study shows children with multidrug-resistant tuberculosis can be treated

August 21, 2018
The results of a large, international systematic review published in the journal PLOS Medicine show that tuberculosis treatment is successful in children with multidrug-resistant tuberculosis (MDR-TB). The study was used ...

Largest oral HPV study in England shows infection rates lower than expected

August 20, 2018
Infection rates of high risk human papillomavirus (HR-HPV) oral infection in England are lower than expected, compared to previous US studies.

Tibetan sheep highly susceptible to human plague, originates from marmots

August 16, 2018
In the Qinghai-Tibet plateau, one of the region's highest risk areas for human plague, Himalayan marmots are the primary carriers of the infectious bacterium Y. pestis. Y. pestis infection can be transmitted to humans and ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.