Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UCLA scientists identify novel pathway for T-cell activation in leprosy

26.03.2012
Finding may help develop new treatments for infectious diseases, cancer

UCLA researchers pinpointed a new mechanism that potently activates T-cells, the group of white blood cells that play a major role in fighting infections.

Published March 25 online in Nature Medicine, the team specifically studied how dendritic cells, immune cells located at the site of infection, become more specialized to fight the leprosy pathogen known as Mycobacterium leprae. Dendritic cells, like scouts in the field of a military operation, deliver key information about an invading pathogen that helps activate the T-cells in launching a more effective attack.

It was previously known that dendritic cells were important for a strong immune response and the number of such cells at an infection site positively correlated with a robust reaction. However, until now it was poorly understood how dendritic cells become more specialized to address specific types of infections.

The researchers found that a protein called NOD2 triggers a cell-signaling molecule called interleukin-32 that induces general immune cells called monocytes to become specialized information-carrying dendritic cells.

"This is the first time that this potent infection-fighting pathway with dendritic cells has been identified, and demonstrated to be important in fighting human disease," said the study's first author Mirjam Schenk, postdoctoral scholar, division of dermatology, David Geffen School of Medicine at UCLA.

In conducting the study, scientists used monocytes taken from the blood of healthy donors and leprosy patients and incubated the cells with the pathogen M. Leprae or specific parts of the mycobacteria, known to trigger NOD2 and TLR2, both associated with immune system activation.

Scientists wanted to investigate how these proteins might trigger mechanisms that turn on different immune receptors that recognize specific parts of the microbe in an infection. The NOD2 interleukin-32 pathway was the most effective and caused monocytes to develop into dendritic cells that carry critical information about the pathogen to the T-cells.

The team studied the gene expression profiles of the protein-triggered pathways and then also examined how the monocytes of leprosy patients responded to NOD2. Scientists found that NOD2 worked to induce moncytes to dendritic cells in tuberloid leprosy, a milder infection that is more easily contained. The NOD2 pathway was inhibited and could not be activated in lepromatous leprosy, which is more serious and causes widespread infection throughout the body.

"We were surprised to find the high potency of the dendritic cells in triggering certain specific T-cell responses, which may be useful in developing new therapeutic strategies for infectious diseases and cancer," said senior investigator Dr. Robert Modlin, UCLA's Klein Professor of Dermatology and chief of dermatology at the Geffen School of Medicine.

Leprosy, one of the world's oldest known diseases, is a chronic infectious disease that affects the skin, the peripheral nerves, the upper respiratory tract and the eyes and can lead to disfigurement of the hands, face and feet. In 2008, approximately 249,000 new cases of leprosy were reported worldwide, according to the World Health Organization.

Modlin adds that leprosy is a good model to study immune mechanisms in host defense since it presents as a clinical spectrum that correlates with the level and type of immune response of the pathogen.

The next stage of research will involve trying to further understand how to manipulate the innate immune system to induce a potent immune response in human infections and possibly for cancer immunotherapy as well.

The study was funded by the NIH's National Institute of Allergy and Infectious Diseases and National Institute of Arthritis and Musculoskeletal and Skin Diseases. (Grant numbers: RO1s AI022553, AR040312 and AI047868.)

Additional authors include: Stephan R Krutzik, Peter A Sieling, Delphine J. Lee, Rosane M. B. Teles, and Maria Teresa Ochoa from the Division of Dermatology, Department of Medicine, David Geffen School of Medicine at UCLA; Genhong Cheng, Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine at UCLA; Evangelia Komisopoulou and Thomas G. Graeber, Crump Institute for Molecular Imaging, Institute for Molecular Medicine, Jonsson Comprehensive Cancer Center, California NanoSystems Institute, Department of Molecular and Medical Pharmacology, UCLA; Euzenir N. Sarno, Department of Mycobacteriosis, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil; Thomas H. Rea, Department of Dermatology, University of Southern California School of Medicine, Los Angeles, California and Soohyun Kim, Department of Biomedical Science and Technology, Konkuk University, Seoul Korea.

Rachel Champeau | EurekAlert!
Further information:
http://www.mednet.ucla.edu

More articles from Health and Medicine:

nachricht Antibiotic effectiveness imperiled as use in livestock expected to increase
27.03.2015 | Princeton University

nachricht A human respiratory tissue model to assess the toxicity of inhaled chemicals and pollutants
26.03.2015 | R&D at British American Tobacco

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energy-autonomous and wireless monitoring protects marine gearboxes

The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.

As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...

Im Focus: 3-D satellite, GPS earthquake maps isolate impacts in real time

Method produced by UI researcher could improve reaction time to deadly, expensive quakes

When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.

Im Focus: Atlantic Ocean overturning found to slow down already today

The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe. 

Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...

Im Focus: Robot inspects concrete garage floors and bridge roadways for damage

Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.

From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

10. CeBiTec Symposium zum Big Data-Problem

17.03.2015 | Event News

 
Latest News

Two Most Destructive Termite Species Forming Superswarms in South Florida

27.03.2015 | Agricultural and Forestry Science

ORNL-Led Team Demonstrates Desalination with Nanoporous Graphene Membrane

27.03.2015 | Materials Sciences

Coorong Fish Hedge Their Bets for Survival

27.03.2015 | Ecology, The Environment and Conservation

VideoLinks
B2B-VideoLinks
More VideoLinks >>>