Corporate Banner
Satellite Banner
Immunology
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

NIAID Study Identifies Immune Sensors of Malnutrition

Published: Monday, January 27, 2014
Last Updated: Monday, January 27, 2014
Bookmark and Share
Leading research to understand, treat, and prevent infectious, immunologic, and allergic diseases.

In a new study, NIAID scientists describe how the immune system responds to malnutrition by adjusting the types of immune cells in the gastrointestinal tract. In a mouse model of vitamin A deficiency, they observed the expansion of type 2 innate lymphoid (ILC2) cells, which are essential for immune responses against nutrient-depleting helminth, or parasitic worm, infections. The study appears in the January 23, 2014, online issue of Science.

Background
The impact of nutrition on the immune system is an important research focus with broad impact. Vitamin A deficiency is estimated to affect up to 250 million children worldwide, particularly in regions where chronic helminth infections and malnutrition are prevalent. It is the leading cause of preventable blindness in children and is associated with higher rates of severe diarrheal disease.

In the body, vitamin A is broken down into a product called retinoic acid (RA), which is essential for growth and development. RA also is necessary for the immune system, and without it, classes of T cells fail to develop or function, enhancing susceptibility to infections.

Yasmine Belkaid, Ph.D., and her research team in NIAID's Laboratory of Parasitic Diseases reasoned that the immune system compensates for the effects of vitamin A deficiency because people can survive for extended periods of malnutrition. One of the minimum requirements for survival is to maintain immunity at barrier surfaces, like the gastrointestinal tract and lungs. These locations are enriched for innate lymphoid cells, which come in three classes: ILC1, ILC2, and ILC3. The NIAID team sought to examine how vitamin A deficiency impacts ILCs and barrier defenses.

Results of Study
Dr. Belkaid and colleagues used a mouse model of vitamin A deficiency to examine how malnutrition affects immunity along the gastrointestinal tract. In mice lacking vitamin A or RA, the ILC3 subset, which typically provides antibacterial immunity, was diminished in the gut. As such, the malnourished mice were more susceptible to infection with the bacterium Citrobacter rodentium, a model for the disease-causing forms of Escherichia coli.

Surprisingly, however, mice lacking vitamin A or RA had significantly more ILC2 in the gut. The ILC2 subset typically provides immune defense against helminths. Compared to nourished mice, the malnourished ones had similar or even better immune responses against infection with the parasitic worm Trichuris muris.

Significance
This study identifies ILCs as sensors of malnutrition that alter gut immunity in response to diet. For vitamin A deficiency, RA is the key switch that directs these changes. Contrary to common belief, this work shows that nutrient deficiency does not equal global immunosuppression, as antihelminth immunity is actually promoted and enhanced.

The results of this study also correlate with observations of children who suffer from vitamin A deficiency. They are more susceptible to gastrointestinal bacterial infections but also tend to live in areas with chronic helminth infections, which compete with their hosts for essential nutrients.

While more work is needed to address the role of malnutrition on ILCs in people, this shift in cell types may be a response to temporarily boost survival against debilitating helminth infections during malnutrition.

Next Steps
The researchers will examine how other nutrient deficiencies affect the immune system and how this may influence vaccination outcomes. Vaccines are developed to enhance specific immune responses, but the nutritional state of intended recipients is rarely incorporated into studies. Understanding how nutrition affects the immune system promises to help optimize vaccine design and development, particularly for diseases that affect regions where malnutrition is prevalent.

The ILC2 subtype also is important for tissue repair. Understanding how nutrition influences ILC2 activity will provide new insight on effective therapies for inflammatory diseases like Crohn's disease, an inflammatory bowel disorder, and autoimmunity.


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,500+ scientific posters on ePosters
  • More than 3,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Experimental MERS Vaccine Shows Promise in Animal Studies
A two-step regimen of experimental vaccines against Middle East respiratory syndrome (MERS) prompted immune responses in mice and rhesus macaques, report National Institutes of Health scientists who designed the vaccines.
Thursday, July 30, 2015
Scientists Identify Gene that Allows Malaria Parasite to Survive in Mosquitoes
NIAID researchers have identified a gene that helps malaria-causing parasites elude the mosquito immune system, allowing the microbes to transmit efficiently to people when the insect takes a blood meal.
Friday, May 10, 2013
Scientific News
Inciting an Immune Attack on Cancer Cells
A new minimally invasive vaccine that combines cancer cells and immune-enhancing factors could be used clinically to launch a destructive attack on tumors.
Inflammation Linked to Colon Cancer Metastasis
A new Arizona State University research study led by Biodesign Institute executive director Raymond DuBois has identified for the first time the details of how inflammation triggers colon cancer cells to spread to other organs, or metastasize.
New Strategy for Combating Adenoviruses
Using an animal model they developed, Saint Louis University and Utah State university researchers have identified a strategy that could keep a common group of viruses called adenoviruses from replicating and causing sickness in humans.
Major Advance Toward More Effective, Long-Lasting Flu Vaccine
Collaboration shows vaccine candidate can produce powerful ‘broadly neutralizing antibodies’ in animal models.
Immune System: Help for Killer Cells
A study from the University of Bonn may show the way to more effective vaccines.
Protein Found to Control Inflammatory Response
A new Northwestern Medicine study shows that a protein called POP1 prevents severe inflammation and, potentially, diseases caused by excessive inflammatory responses.
A Leap Forward in Vaccinating Against HIV
A team of scientists has developed an experimental vaccine candidate that successfully stimulates the immune system activity in animal models necessary to stop HIV infection.
MRI Scanners Can Steer Therapeutics to Specific Target Sites
Scientists from the University of Sheffield have discovered MRI scanners, normally used to produce images, can steer cell-based, tumour busting therapies to specific target sites in the body.
Agricultural Intervention Improves HIV Outcomes
A multifaceted farming intervention can reduce food insecurity while improving HIV outcomes in patients in Kenya, according to a randomized, controlled trial led by researchers at UC San Francisco.
Team Finds Early Inflammatory Response Paralyzes T Cells
Findings could have enormous implications for immunotherapy, autoimmune disorders, transplants and other aspects of immunity.
SELECTBIO

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!