Sign up for our daily briefing

Make your busy days simpler with Axios AM/PM. Catch up on what's new and why it matters in just 5 minutes.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Denver news in your inbox

Catch up on the most important stories affecting your hometown with Axios Denver

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Des Moines news in your inbox

Catch up on the most important stories affecting your hometown with Axios Des Moines

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Minneapolis-St. Paul news in your inbox

Catch up on the most important stories affecting your hometown with Axios Twin Cities

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Tampa Bay news in your inbox

Catch up on the most important stories affecting your hometown with Axios Tampa Bay

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Charlotte news in your inbox

Catch up on the most important stories affecting your hometown with Axios Charlotte

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Nati Harnik / AP

A new study published Wednesday may help scientists develop preventative measures against gestational diabetes, recurrent spontaneous miscarriage, and other pregnancy complications.

What they found: The human immune system matures in utero as early as the second trimester but has a tweak — a greater amount of protein arginase-2 — which may allow for greater immune tolerance, according to the scientists behind the semi-controversial study.

Why the findings matter: The knowledge could help guide the timing of intra-uterine stem cell transplants or other gene therapies that could save the life of a fetus or help prevent immune-related issues like gestational diabetes and miscarriages, per an article in Nature. The knowledge could also be applied to helping remedy some adult afflictions, like avoiding the rejection of organ transplants.

Study author Florent Ginhoux told Axios the study was the first to have "clearly mapped the system of this network of cells in human tissue." He said little is known about the initial stages of development for cells central to the immune system in the womb due to ethical concerns surrounding the use of fetal tissue in experiments.

Study details: Ginhoux teamed up with Singapore clinician Jerry Chan, who conducts experimental gene and cell therapies to treat fetal diseases. They studied tissues from 96 fetuses (from clinically indicated pregnancy terminations) from the second trimester of pregnancy and sorted out the immune cells, which they found in the skin, spleen, thymus, and lungs. They exposed the cells to toxic antigens and to non-related adult cells to see if they would trigger an immune response.

Similar to adult cells: They found there were immunologically active cells, called dendritic cells, which showed the capacity to both sense pathogens and stimulate T cells in the second trimester of gestation. The fetal dendritic cells responded to regular antigens in a similar manner as adult dendritic cells react.

Different from adult cells: However, when exposed to adult cells as the antigen, the fetal dendritic cells did not respond with an immune response as adult cells would (think of the immune problems with kidney transplants) but dampened the immune response. The team said the cause of this may be greater amounts of the protein arginase-2, which is found in abundance in fetal dendritic cells but not adult ones.

Immune tolerance and going forward: Arginase-2 is the likely explanation of "immune tolerance" between mother and fetus, where neither immune system attacks the other, Ginhoux said. He said this is important because further studies could see if this tolerance can be applied to adults. While this study discovered one pathway of immunosuppression, Ginhoux said more research is needed to discover other pathways of immunosuppression and to completely map whole system of cell development in fetuses.

Go deeper

Updated 3 hours ago - Politics & Policy

Coronavirus dashboard

Illustration: Eniola Odetunde/Axios

  1. Health: Most vulnerable Americans aren't getting enough vaccine information — Fauci says Trump administration's lack of facts on COVID "very likely" cost lives.
  2. Politics: Biden unveils "wartime" COVID strategyBiden's COVID-19 bubble.
  3. Vaccine: Florida requiring proof of residency to get vaccine — CDC extends interval between vaccine doses for exceptional cases.
  4. World: Hong Kong to put tens of thousands on lockdown as cases surge.
  5. Sports: 2021 Tokyo Olympics hang in the balance.
  6. 🎧 Podcast: Carbon Health's CEO on unsticking the vaccine bottleneck.

Trump impeachment trial to start week of Feb. 8, Schumer says

Senate Majority Leader Chuck Schumer. Photo: The Washington Post via Getty

The Senate will begin former President Trump's impeachment trial the week of Feb. 8, Majority Leader Chuck Schumer announced Friday on the Senate floor.

The state of play: Schumer announced the schedule after reaching an agreement with Republicans. The House will transmit the article of impeachment against the former president late Monday.

4 hours ago - Health

CDC extends interval between COVID vaccine doses for exceptional cases

Photo: Joseph Prezioso/AFP via Getty

Patients can space out the two doses of the coronavirus vaccine by up to six weeks if it’s "not feasible" to follow the shorter recommended window, according to updated guidance from the Centers for Disease and Control and Prevention.

Driving the news: With the prospect of vaccine shortages and a low likelihood that supply will expand before April, the latest changes could provide a path to vaccinate more Americans — a top priority for President Biden.