Study suggests lung microbiota promotes tolerance to allergens in neonates

May 12, 2014 by Bob Yirka report
Lung tissue. Credit: Rutgers University

(Medical Xpress)—A study by a team made up of researchers from Switzerland and the U.K. has determined that lung microbiota in neonate mice promotes tolerance to allergens both early on and later in life. In their paper published in the journal Nature Medicine, the group reports on experiments they conducted in a lab that involved testing mice soon after birth for microbiota levels and types in the lungs and their tolerance to allergens.

Reports that over-cleaning a newborn's environment could lead to a compromised immune system have been surfacing in recent years and indeed some studies have found that children raised in near sterile environments tend to have more problems with asthma and other allergies as they grow older. In this new effort, the researchers sought to find a concrete connection between microbiota in the lungs of newborn , and their subsequent tolerance to .

Mice (and humans) are born with sterile lungs, shortly after birth however, various forms of microbiota begin to take up residence, which in most cases, is believed to help ward off allergens. The researchers in this study tested the mice in various ways. First, they tested allergen response immediately after birth, before microbiota had built up. Test results showed a high incidence of inflammation. At just two weeks old, the young mice had built up an impressive array of biota in their lungs, and testing showed, a marked increase in resistance to allergens. After two months, the mice showed a high degree of immune response to allergens. In another test, they kept some young mice in sterile environments, preventing microbiota build up in their lungs. When introduced to allergens, the older mice reacted in ways similar to newborns, i.e. they exhibited a high incidence of .

The researchers suggest their work indicates that play a major role in immune development in mice, and possibly in other mammals. They believe that because of what they found, that its more likely that such mammals would be more susceptible to asthma later on in life, and because of that, suggest that parents of newborns refrain from using antibacterial wipes and soaps, and instead use simple soap and water when washing up to allow their baby to develop an immunity at a very early age.

Explore further: Gut microbiota may play a role in the development of alcoholic liver disease

More information: Lung microbiota promotes tolerance to allergens in neonates via PD-L1, Nature Medicine (2014) DOI: 10.1038/nm.3568

Abstract
Epidemiological data point toward a critical period in early life during which environmental cues can set an individual on a trajectory toward respiratory health or disease. The neonatal immune system matures during this period, although little is known about the signals that lead to its maturation. Here we report that the formation of the lung microbiota is a key parameter in this process. Immediately following birth, neonatal mice were prone to develop exaggerated airway eosinophilia, release type 2 helper T cell cytokines and exhibit airway hyper-responsiveness following exposure to house dust mite allergens, even though their lungs harbored high numbers of natural CD4+Foxp3+CD25+Helios+ regulatory T (Treg) cells. During the first 2 weeks after birth, the bacterial load in the lungs increased, and representation of the bacterial phyla shifts from a predominance of Gammaproteobacteria and Firmicutes towards Bacteroidetes. The changes in the microbiota were associated with decreased aeroallergen responsiveness and the emergence of a Helios− Treg cell subset that required interaction with programmed death ligand 1 (PD-L1) for development. Absence of microbial colonization10 or blockade of PD-L1 during the first 2 weeks postpartum maintained exaggerated responsiveness to allergens through to adulthood. Adoptive transfer of Treg cells from adult mice to neonates before aeroallergen exposure ameliorated disease. Thus, formation of the airway microbiota induces regulatory cells early in life, which, when dysregulated, can lead to sustained susceptibility to allergic airway inflammation in adulthood.

Related Stories

Gut microbiota may play a role in the development of alcoholic liver disease

April 12, 2014
Exciting new data presented today at the International Liver Congress 2014 shows that the gut microbiota has a potential role in the development of alcoholic liver disease (ALD).1 Though an early stage animal model, the French ...

Breastfeeding promotes the growth of beneficial bacteria in the gut

May 7, 2014
A number of studies have shown that breastfed babies grow slightly slower and are slightly slimmer than children who are fed with infant formula. Children who are breastfed also have a slightly lower incidence of obesity, ...

Research shows how household dogs protect against asthma and infection

December 16, 2013
Children's risk for developing allergies and asthma is reduced when they are exposed in early infancy to a dog in the household, and now researchers have discovered a reason why.

Gut microbiota transplantation may prevent development of diabetes and fatty liver disease

April 19, 2012
Exciting new data presented today at the International Liver Congress 2012 shows the gut microbiota's causal role in the development of diabetes and non-alcoholic fatty liver disease (NAFLD), independent of obesity.(1) Though ...

IL-27 balances the immune response to influenza and reduces lung damage

May 8, 2014
Highly pathogenic (dangerous) influenza strains elicit a strong immune response which can lead to uncontrolled inflammation in the lung and potentially fatal lung injury. A study published on May 8th in PLOS Pathogens demonstrates ...

What makes the newborn immune system in the lungs different and vulnerable?

February 13, 2014
Newborns are more susceptible to infections, presumably because of their immature and inexperienced immune systems. The most common dangerous condition in newborns and infants are lower respiratory tract infections caused ...

Recommended for you

Want to win at sports? Take a cue from these mighty mice

July 20, 2017
As student athletes hit training fields this summer to gain the competitive edge, a new study shows how the experiences of a tiny mouse can put them on the path to winning.

'Smart' robot technology could give stroke rehab a boost

July 19, 2017
Scientists say they have developed a "smart" robotic harness that might make it easier for people to learn to walk again after a stroke or spinal cord injury.

Engineered liver tissue expands after transplant

July 19, 2017
Many diseases, including cirrhosis and hepatitis, can lead to liver failure. More than 17,000 Americans suffering from these diseases are now waiting for liver transplants, but significantly fewer livers are available.

Lunatic Fringe gene plays key role in the renewable brain

July 19, 2017
The discovery that the brain can generate new cells - about 700 new neurons each day - has triggered investigations to uncover how this process is regulated. Researchers at Baylor College of Medicine and Jan and Dan Duncan ...

New animal models for hepatitis C could pave the way for a vaccine

July 19, 2017
They say that an ounce of prevention is worth a pound of cure. In the case of hepatitis C—a disease that affects nearly 71 million people worldwide, causing cirrhosis and liver cancer if left untreated—it might be worth ...

Omega-3 fatty acids fight inflammation via cannabinoids

July 18, 2017
Chemical compounds called cannabinoids are found in marijuana and also are produced naturally in the body from omega-3 fatty acids. A well-known cannabinoid in marijuana, tetrahydrocannabinol, is responsible for some of its ...

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.