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:12/1/2015)... ME (PRWEB) , ... December 01, 2015 , ... Royal ... reports a new study that found post-menopausal women who took the nutritional supplement creatine, ... than women who trained but did not take creatine. , The report is part ...
(Date:12/1/2015)... ... ... is the first health care provider in the region to offer the vBloc® Therapy ... vagal blocking therapy, delivered via the Maestro® System, for the treatment of adult patients over ... to 45 kg, or a BMI of at least 35 to 39.9 kg with a ...
(Date:12/1/2015)... , ... December 01, 2015 , ... ... oncology and hematology continuing medical education (CME), today announced that the first annual ... Hyatt New York. , “The prevention, detection and treatment of gastrointestinal cancers are ...
(Date:12/1/2015)... ... December 01, 2015 , ... Califia Farms , ... that its iconic bottle has won top honors in Beverage World Magazine’s Global Packaging ... also announced that it has been selected as a 2015 U.S.A. Taste Champion in ...
(Date:12/1/2015)... , ... December 01, 2015 , ... ... there are professionals who believe that with innovative technologies and under the right ... patient to get the benefit of a dual-approach to his or her therapeutic ...
Breaking Medicine News(10 mins):
(Date:12/1/2015)... 2015  Athletic apparel company Tommie Copper ... pay $1.35 million to settle Federal Trade Commission ... compression clothing would relieve severe and chronic pain ... Tommie Copper,s proposed settlement ... its founder and chairman Thomas Kallish ...
(Date:12/1/2015)... and PITTSBURGH , Dec. ... announced that it expects to be the first to ... funded by international donors, TLE400 (Tenofovir Disoproxyl Fumarate 300 ... for $99 per patient, per year. Mylan partnered with ... The significantly reduced price could generate savings of tens ...
(Date:12/1/2015)... Virginia , 1 de diciembre de ... en tecnología para cuchillas de precisión, develó ... programa de identidad de marca. El nuevo ... el diseño y la ingeniería de productos ... la diferencia". ...
Breaking Medicine Technology: