Science News
from research organizations

Why do infants get sick so often? Cell signaling prevents growth of essential immune cells, study shows

Date:
August 7, 2012
Source:
University of Michigan Health System
Summary:
Babies can get sick often, but parents shouldn't take the blame. A new study shows essential immune cells that help fight infections don't develop until adulthood.
Share:
       
FULL STORY

Researchers are helping to quell parents' worry about why infants seem to get sick so often.
Credit: © Yuri Arcurs / Fotolia

Researchers at the University of Michigan Health System are helping to quell parents' worry about why infants seem to get sick so often.

It's been believed that, like walking and talking, fighting viral infections is something children will develop when they get older. But a U-M study suggests the natural ability to fight infection is there early on.

Scientists learned key cell signals inhibit the growth of essential immune cells early in life. Blocking this signaling could lead to improving an infant's response to infection, according to the study published online ahead of print in Nature Immunity.

"What happens at early age is that natural killer cells, like many other immune cells, do not complete their functional maturation until adulthood," says study senior author Yasmina Laouar, Ph.D., assistant professor in the U-M Department of Microbiology and Immunology.

"During this time we are left with an immature immune system that cannot protect us against infections, the reason why newborns and infants are more prone to infection," she says.

There is a large gap in understanding infant immunity, specifically why the natural killer cell responses are deficient. The study by immunologists at the U-M demonstrates the role of a cell called transforming growth factor beta that can explain why.

The study showed the production of natural killer cells is controlled by TGF-β, which is produced in the bone marrow. In infant mice, the maturation of natural killer cells progressed faster in the absence of TGF-β signaling.

By adulthood, mice had 10 times more mature natural killer cells if TGF-β signaling was blocked.

"Our overall goal was to determine the factors that constraint the production and maturation of natural killer cells early in life," says Laouar. "To our surprise, we discovered that natural killer cells can complete maturation as early as 10 days of age if TGF-β signaling is blocked."

Authors say it's tempting to propose the functional inactivation TGF-β signaling as a strategy to reverse the deficit of natural killer cells early in life. Additional testing will be required.


Story Source:

The above post is reprinted from materials provided by University of Michigan Health System. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jeffrey P Marcoe, James R Lim, Keri L Schaubert, Nassima Fodil-Cornu, Marsel Matka, Alexandra L McCubbrey, Alexander R Farr, Silvia M Vidal, Yasmina Laouar. TGF-β is responsible for NK cell immaturity during ontogeny and increased susceptibility to infection during mouse infancy. Nature Immunology, 2012; DOI: 10.1038/ni.2388

Cite This Page:

University of Michigan Health System. "Why do infants get sick so often? Cell signaling prevents growth of essential immune cells, study shows." ScienceDaily. ScienceDaily, 7 August 2012. <www.sciencedaily.com/releases/2012/08/120807101334.htm>.
University of Michigan Health System. (2012, August 7). Why do infants get sick so often? Cell signaling prevents growth of essential immune cells, study shows. ScienceDaily. Retrieved July 6, 2015 from www.sciencedaily.com/releases/2012/08/120807101334.htm
University of Michigan Health System. "Why do infants get sick so often? Cell signaling prevents growth of essential immune cells, study shows." ScienceDaily. www.sciencedaily.com/releases/2012/08/120807101334.htm (accessed July 6, 2015).

Share This Page: