Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

T cell’s memory may offer long-term immunity to leishmaniasis

08.10.2004


Researchers at the University of Pennsylvania have discovered a "central memory" form of "helper" T cells that can offer immunity to leishmaniasis, a disease that causes considerable death and disfigurement across the globe and has been found in U.S. military personnel returning from Afghanistan and Iraq.



In the October issue of Nature Medicine, the Penn researchers describe how the discovery can offer immunity to leishmaniasis, even without the persistent presence of the parasite that caused the disease. Their findings encourage a new approach to creating a vaccine against leishmaniasis and other immune cell mediated diseases such as tuberculosis and HIV/AIDS.

Attempts to create a vaccine for leishmaniasis have long been stymied by the fact that the helper T cells, which coordinate the immune response against a pathogen, need constant stimulation from the pathogen in order to remain effective against the disease. "Without the persistent attack from the Leishmania parasite, the immune system does not keep protective CD4+ T cells in place," said Phillip Scott, professor and chair of the Department of Pathobiology at Penn’s School of Veterinary Medicine. "The strategy of most vaccines, to ’teach’ the immune system to remember a pathogen, just doesn work with leishmaniasis.


"We have found that a new form of long-term memory T cell will, if stimulated, turn into the sort of helper T cells that mediate the immune response. We believe that, if we can stimulate the expansion of these central memory T cells, we ought to be able to create an effective vaccine."

Leishmaniasis is a parasitic disease spread by the bite of sand flies infected with the protozoan Leishmania. While the disease is most common in North Africa, the Middle East and Asia, it has been recently been seen in United States military personnel who have served in Afghanistan and Iraq.

According to the Centers for Disease Control, each year the world sees 1.5 million new cases of cutaneous leishmaniasis, which infects the skin, causing scarring boils, and 500,000 new cases of visceral leishmaniasis, which infects internal organs, causing death if left untreated.

Particularly vexing to researchers has been the fact that while people who recover from leishmaniasis generally develop lifelong immunity to reinfection, this has been thought to depend upon the continued presence of the Leishmania parasite. Indeed, it has been shown in mice that if the parasite is entirely removed, the host can become reinfected with disease.

Scott and his colleagues wondered if, despite the apparent loss of immunity when the parasites disappeared, there were any T cells that still retained memory of Leishmania. Recent studies have shown that memory T cells may be of more than one type. One type, which is less activated and found in the lymph nodes, is called central memory T cells. Since little is known about CD4+ T cell memory during chronic disease, the Penn researchers set out to find if such central memory cells exist in leishmaniasis.

The hunt for the theoretical CD4+ central memory T cells began by transferring T cells from mice infected with leishmaniasis to mice who had never faced the disease. According to Scott, some of the transferred T cells went to the lymph nodes, and had the characteristics of central memory cells.

"We see that these central memory T cells but not the effector T cells persist in the absence of obvious parasites for as long as five months," Scott said. "Since we still do not know much about these new T cells, our next step is to find out how we can encourage the proliferation of central memory cells and stimulate them to fight disease."

According to Scott, a better understanding of central memory T cells may lead to the development of vaccines that fight off a range of pathogens that respond well to a helper T cell response.

Funding for this research was provided through grants from the National Institutes of Health

Greg Lester | EurekAlert!
Further information:
http://www.upenn.edu

More articles from Life Sciences:

nachricht Scientists unlock ability to generate new sensory hair cells
22.02.2017 | Brigham and Women's Hospital

nachricht New insights into the information processing of motor neurons
22.02.2017 | Max Planck Florida Institute for Neuroscience

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>