Featured Research

from universities, journals, and other organizations

New genetic mechanism of immune deficiency discovered

Date:
April 20, 2012
Source:
National Jewish Health
Summary:
Researchers have discovered a mutation in the gene Unc119, which causes an immune deficiency known as CD4 lymphopenia.

Researchers at National Jewish Health have discovered a novel genetic mechanism of immune deficiency. Magdalena M. Gorska, MD, PhD, and Rafeul Alam, MD, PhD, identified a mutation in Unc119 that causes immunodeficiency known as idiopathic CD4 lymphopenia. Unc119 is a signaling protein that activates and induces T cell proliferation. The mutation impairs Unc119 ability to activate T cells. Dr. Gorska, will present her findings April 20 at Translational Science 2012, an NIH-funded conference in Washington D.C.

"A better understanding of the molecular mechanisms associated with this mutation will improve diagnosis and pave the way for development of new therapies," said Dr. Gorska.

Drs. Gorska and Alam previously published their findings in the journal Blood, and Dr. Gorska delivered a Presidential Plenary on the topic at the annual meeting of the American Academy of Allergy Asthma & Immunology.

Nearly a decade ago Drs. Alam and Gorska identified Unc119 as a novel activator of SRC-type tyrosine kinases, important regulators of cellular function. Since then, they have published numerous papers where they characterized the function of this protein in various aspects of the immune system.

Idiopathic CD4 lymphopenia is a rare and heterogeneous syndrome defined by low levels of CD4 T cells in the absence of HIV infection, which predisposes patients to infections and malignancies. Recent research by others had linked the syndrome to reduced activation of the SRC-type kinase known as Lck. The latter kinase is involved in T cell development, activation and proliferation.

So, Drs. Alam and Gorska thought Unc119, an activator of Lck, might be involved. They kept an eye out for patients with CD4 lymphopenia coming to National Jewish Health, which specializes in immune-related disorders as well as respiratory and cardiac diseases. They identified three patients with CD4 lymphopenia, then sequenced their Unc119 gene as well as the Unc119 gene in several patients who suffered low CD4 T cell counts as a result of other conditions.

One of the three patients, a 32-year-old woman with a history of recurrent infections, had a missense mutation in her Unc119 gene. The same mutation was not present in other lymphopenia patients nor in any genetic database.

The researchers then performed several studies with the woman's blood cells, to understand the mutation's effect. They introduced the mutated gene into normal T cells and examined the outcome.

The mutation prevents Lck activation and its downstream signaling. It also reduces the amount of Lck found near the plasma membrane, where it plays a major role in propagating signals from the T-cell receptor. Proliferation of T cells, which normally occurs on stimulation of T-cell receptors, was profoundly reduced in cells from the patient.

"Since we originally published our findings earlier this year, we have received inquiries from many physicians with lymphopenia subjects," said Dr. Alam. "Working with them, we expect to find several more patients with this novel mutation, which should help us better understand its effect, improve diagnosis and possibly find therapies."

At this point there is no treatment for CD4 lymphopenia caused by this mutation other than close monitoring of the patient and treatment of resulting infections and malignancies.


Story Source:

The above story is based on materials provided by National Jewish Health. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. M. Gorska, R. Alam. A mutation in the human Uncoordinated 119 gene impairs TCR signaling and is associated with CD4 lymphopenia. Blood, 2011; 119 (6): 1399 DOI: 10.1182/blood-2011-04-350686

Cite This Page:

National Jewish Health. "New genetic mechanism of immune deficiency discovered." ScienceDaily. ScienceDaily, 20 April 2012. <www.sciencedaily.com/releases/2012/04/120420143853.htm>.
National Jewish Health. (2012, April 20). New genetic mechanism of immune deficiency discovered. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2012/04/120420143853.htm
National Jewish Health. "New genetic mechanism of immune deficiency discovered." ScienceDaily. www.sciencedaily.com/releases/2012/04/120420143853.htm (accessed April 19, 2014).

Share This



More Health & Medicine News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com
Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins