Nav: Home

High-risk pregnancy: The interferon effect

July 11, 2019

High-risk pregnancies occur frequently and may be caused by various factors. It is estimated that 10 to 20% of pregnant women miscarry during their first trimester of pregnancy. Slow fetal growth may also arise as a result of maternal infection with certain microbes, parasites or viruses (such as toxoplasmosis or infection with rubella virus, cytomegalovirus, herpes or Zika) or because of genetic or autoimmune diseases. Teams from the Institut Pasteur, the CNRS, Inserm, Necker-Enfants Malades Hospital (AP-HP) and Université de Paris have identified a new cellular mechanism that alters placental development, potentially causing serious complications during pregnancy. The mechanism is linked with the production of interferon, a molecule produced in response to infection, especially viral infection. The findings are published in Science on July 11, 2019.

The placenta is both a surface for exchange and a barrier between mother and fetus - it delivers nutrients needed for fetal growth, produces hormones and protects the fetus from microbes and the maternal immune system. The external layer of the placenta, known as the syncytiotrophoblast, is composed of cells which fuse together, forming giant cells that are optimized for the placenta's barrier and exchange functions. Cell fusion is mediated by a protein known as syncytin. If the syncytiotrophoblast fails to form correctly, it can cause placental insufficiency and hinder fetal development. An abnormal syncytiotrophoblast can be observed in conditions such as slow intrauterine growth, the lupus and in women whose fetus has Down syndrome.

Interferon is a substance produced by immune cells during infection to combat viruses and other intracellular microbes. High levels of interferon are observed in autoimmune or inflammatory diseases such as lupus, and also in some infections. In this study, the scientists demonstrated that interferon is responsible for placental abnormality and that it acts by preventing syncytiotrophoblast formation. Specifically, interferon induces the production of a family of cellular proteins known as IFITMs (interferon-induced transmembrane proteins), which block the fusion activity of syncytin.

IFITM proteins are beneficial since they prevent viral fusion with cellular membrane, thereby stopping viruses from entering and multiplying within cells. The scientists used experimental models and human cells to demonstrate that this beneficial effect can nevertheless be harmful if IFITM proteins are produced in an important level in the placenta.

"Identifying the role of IFITMs gives us a better understanding of the mechanisms involved in placental development and how it may be disrupted during infections and other diseases," comments Olivier Schwartz, Head of the Virus and Immunity Unit at the Institut Pasteur and joint last author of the paper. The scientists want to investigate whether placental pathologies of unknown etiology, such as some early spontaneous abortions and occurrences of preeclampsia, also involve IFITM proteins. In the longer term, blocking the effects of IFITMs could represent a new therapeutic strategy to prevent interferon-related placental abnormality.
-end-
In addition to the institutions mentioned above, this research was funded by the ANRS, Sidaction, the French Vaccine Research Institute (VRI), LabEx IBEID and the European Research Council (ERC).

INSERM (Institut national de la santé et de la recherche médicale)

Related Pregnancy Articles:

Paracetamol during pregnancy can inhibit masculinity
Paracetamol during pregnancy can inhibit masculinity Paracetamol during pregnancy can inhibit the development of 'male behavior' in mice.
The cost of opioid use during pregnancy
A new study published today by the scientific journal Addiction reveals that the incidence of neonatal abstinence syndrome -- often caused by mothers using opioids during pregnancy -- is increasing in the United States, and carries an enormous burden in terms of hospital days and costs.
New study: Pre-pregnancy BMI directly linked to excess pregnancy weight gain
It's well known that excessive weight gain during pregnancy can have a lasting negative impact on the health of a mother and her baby.
Pregnancy-specific β1-glycoproteins
Development of new strategies and novel drug design to treat trophoblastic diseases and to provide pregnancy success are of crucial importance in maintenance the female reproductive health.
Should hypothyroidism in pregnancy be treated?
When a woman becomes pregnant, many changes occur in her body.
Pre-pregnancy progesterone helps women with recurrent pregnancy loss
Women who have had two or more unexplained miscarriages can benefit from natural progesterone treatment before pregnancy, a new a study from the University of Illinois at Chicago shows.
Male pipefish pregnancy, it's complicated
In the upside-down world of the pipefish, sexual selection appears to work in reverse, with flashy females battling for males who bear the pregnancy and carry their young to term in their brood pouch.
Pregnancy leads to changes in the mother's brain
A study directed by researchers from the UAB and IMIM are the first to reveal how pregnancy causes long-lasting alterations in brain structure, probably related to improving the mother's ability to protect and interact with the child.
MRIs during pregnancy and outcomes for infants, children
In an analysis that included more than 1.4 million births, exposure to magnetic resonance imaging (MRI) during the first trimester of pregnancy compared with nonexposure was not associated with increased risk of harm to the fetus or in early childhood, although gadolinium MRI at any time during pregnancy was associated with an increased risk of a broad set of rheumatological, inflammatory, or skin conditions and, possibly, for stillbirth or neonatal death, according to a study appearing in the Sept.
The benefits of exercise during pregnancy
Women who exercise during pregnancy are more likely to deliver vaginally than those who do not, and show no greater risk of preterm birth.

Related Pregnancy Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Digital Manipulation
Technology has reshaped our lives in amazing ways. But at what cost? This hour, TED speakers reveal how what we see, read, believe — even how we vote — can be manipulated by the technology we use. Guests include journalist Carole Cadwalladr, consumer advocate Finn Myrstad, writer and marketing professor Scott Galloway, behavioral designer Nir Eyal, and computer graphics researcher Doug Roble.
Now Playing: Science for the People

#530 Why Aren't We Dead Yet?
We only notice our immune systems when they aren't working properly, or when they're under attack. How does our immune system understand what bits of us are us, and what bits are invading germs and viruses? How different are human immune systems from the immune systems of other creatures? And is the immune system so often the target of sketchy medical advice? Those questions and more, this week in our conversation with author Idan Ben-Barak about his book "Why Aren't We Dead Yet?: The Survivor’s Guide to the Immune System".