Navigation Links
UGA researchers discover origin of unusual glands in the body

Athens, Ga. The thymus gland is a critical component of the human immune system that is responsible for the development of T-lymphocytes, or T-cells, which help organize and lead the body's fighting forces against harmful organisms like bacteria and viruses.

The main body of the thymus lies beneath the breastbone in the upper chest. But scientists were surprised several years ago when two teams of researchers discovered that both mice and humans have extra thymus-like glands distributed throughout their necks.

Now, researchers at the University of Georgia have published findings in Nature Communications that reveal where these extra glands come from and help explain what roles the extra thymuses may play in the complex network of the body's natural defense systems.

"This was a really important question for me as a developmental biologist studying the thymus," said Nancy Manley, professor of genetics in UGA's Franklin College of Arts and Sciences and principal investigator for the project. "It would almost be akin to someone discovering that humans have extra heart tissue somewhere else in the body."

Manley and her team of researchers discovered that the small satellite thymuses, known as cervical thymi, have two distinct origins, and while it's not entirely clear if they play a major role in human health, the T-cells these thymi produce could be either helpful or harmful.

In the early phases of embryonic development, the cells that form the thymus come from the same cluster of cells that also form the parathyroid glands, which regulate the body's calcium balance. As the fetus develops, these cells separate and turn into distinct tissues, and the cells that make up the thymus move down near the heart while the parathyroid tissues remain in the neck near the thyroid gland.

During this dividing process, there are always a few cells that don't follow the normal path, sticking neither to the thymus nor the thyroid. These castaway cells are scattered and marooned throughout the developing neck.

"It's too late for these cells to join the major glands; eventually some decide to become thymus cells, and this is where cervical thymi come from," said Manley.

Some of these cells turn directly into thymus cells. Others, for reasons not yet fully understood, appear to start out as parathyroid cells, but unexpectedly switch and turn into thymus cells instead.

The ultimate question facing researchers now is whether these satellite thymus glands matter. Are they merely an inconsequential relic of an untidy developmental process? If not, do they help or harm the body?

Manley cautions that it is too early to answer these questions definitively, but the group examined T-cells created by both the direct developing thymi and those derived from parathyroid cells. They discovered that they have very different functions from those found in the main thymus gland.

The thymus cells that began life as parathyroid primarily make a kind of T-cell that is thought to act as an early responder to pathogens in the body.

"They're kind of like the canary in a coal mine," Manley said. "They see something harmful and alert other cells to the problem so they can come and fight the infection."

Cells of this type are relatively rare in the body, but some research suggests that more of them could help the body fight infections more rapidly and completely.

However, both the direct developing and parathyroid-derived thymus cells can also produce autoreactive T-cells.

Just like their helpful cousins, these cells go out and destroy other cells in the body, but they lack the ability to distinguish between normal healthy cells and pathogenic cells like bacteria. Too many of these T-cells can lead to serious autoimmune diseases, such as multiple sclerosis, rheumatoid arthritis and Type 1 diabetes.

Nobody can say with certainty whether having cervical thymi is a good thing or a bad thing for you, Manley said. But answering that question will be a central focus of the team's future research.

Contact: Nancy Manley
University of Georgia

Related medicine news :

1. NIH awards $20 million over 5 years to train next generation of global health researchers
2. Researchers develop a new cell and animal model of inflammatory breast cancer
3. Researchers uncover a viable way for colorectal cancer patients to overcome drug resistance
4. Researchers Find Gene Mutations That May Be a Key to Autism
5. Researchers find evidence of banned antibiotics in poultry products
6. NJ stroke researchers report advances in spatial neglect research at AAN Conference
7. Autism by the numbers: Yale researchers examine impact of new diagnostic criteria
8. Researchers Map Brain Regions Linked to Intelligence
9. Researchers ID Genes That May Determine Mental Illness
10. Researchers Develop Blood Test for Depression
11. University of Cincinnati researchers win $3.7M grant from US Department of Defense
Post Your Comments:
(Date:10/13/2015)... Angeles, CA (PRWEB) , ... October 13, 2015 ... ... growing natural beverage companies in the United States, today announced the release of ... Brew Coffee, and new Cranberry Cocktail Agua Fresca. All feature the unique flavor ...
(Date:10/13/2015)... ... October 13, 2015 , ... ... ENGAGE, at HIMSS’s Patient Engagement Summit . HealthAware is a technology company ... health programs and interventions via mobile devices that provide a framework for the ...
(Date:10/13/2015)... CA (PRWEB) , ... October 13, 2015 , ... ProText ... Pro X . With ProText Kinetic Panel, users can create energetic text animations in ... a preset into the Final Cut Pro X timeline and stylize the text. With ...
(Date:10/13/2015)... (PRWEB) , ... October 13, 2015 , ... Symposium Chairman, ... the 19th annual Dallas Cosmetic Symposium to be held March 2nd and 3rd, 2016. ... immediately afterwards, draws plastic surgeons and cosmetic physicians from around the world. , Key ...
(Date:10/13/2015)... PA (PRWEB) , ... October 13, 2015 , ... In ... 2015 utility costs were 36 percent lower per square foot than in 2009. The ... actual cost of heating and cooling has decreased by eight percent. , According ...
Breaking Medicine News(10 mins):
(Date:10/13/2015)... -- Measurement in accountable care programs is essential for ... gaps in measurement can result in missed opportunities ... new, peer-reviewed study published in The ... measurement gaps for high-priority conditions and identifies ways ... --> "These gaps in measures present ...
(Date:10/13/2015)... DIEGO , Oct. 13, 2015  Nanomedical ... for use in research and diagnostics, announces the ... $1.6 million led by Serra Ventures. ... mission is providing low-cost, easy-to-use monitoring and diagnostic ... health decisions. The funding round will enable the ...
(Date:10/13/2015)... ) ... "US & European Markets for Shoulder Labrum ... to their offering. --> ... "US & European Markets for Shoulder ... report to their offering. --> ...
Breaking Medicine Technology: