Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetically modified parasite lets researchers probe immune system’s memory

21.10.2004


Researchers at Washington University School of Medicine in St. Louis and the University of Pennsylvania have found an immune system cell can "remember" a parasite’s attack and help the body mount a more effective defense against subsequent invasions by the same parasite.



The finding, published in the October issue of Nature Medicine, will likely aid efforts to develop a vaccine for Leishmania major, a parasite that infects approximately 12 million people worldwide, causing significant death and disfigurement. It may also help efforts to develop vaccines for other pathogens including AIDS and tuberculosis.

Scientists have known that successful recovery from Leishmania infection immunizes humans and animals against subsequent infection. But previous experiments led researchers to suspect that this immunity resulted from the presence of a very small population of parasites that remained in the host even after full recovery. Loss of this minimal parasite remnant seemed in some studies to result in loss of immunity.


For the new study, immunologists at the University of Pennsylvania infected mice with a genetically modified form of Leishmania created by microbiologists at Washington University School of Medicine. The modified Leishmania lacks an enzyme required for DNA synthesis and can be completely wiped out by the mouse immune system.

Researchers found that after the mice had cleared the Leishmania parasite, a type of T cell -- the CD4+ central memory T cell -- still reacted to the parasite in the test tube. Mice who never had Leishmania and were given injections of these T cells fought off the parasite more effectively than mice that didn’t get the T cells. "This partial immunization suggests that we may need to look at generating large populations of these memory T cells at the time of vaccination," says study coauthor Stephen Beverley, Ph.D., the Marvin A. Brennecke Professor and head of the Department of Molecular Microbiology.

Researchers also found evidence that another class of T cells may stay primed to fight a new infection when a small remnant population of parasites persists. Beverley speculates that the presence of this second type of T cell, along with the central memory T cell, may be key to providing full protection.

Senior investigator Phillip Scott, Ph.D., professor of microbiology and immunology at the School of Veterinary Medicine at the University of Pennsylvania, has conducted additional experiments that showed central memory T cells can maintain their "memory" of Leishmania and respond to new infections at least 5 months after initial infection.

Because T cells orchestrate the immune system’s fight against other diseases, including tuberculosis and AIDS, scientists believe the new insights will be help efforts to develop other vaccines. "We are so much better at understanding how the immune system responds than we are at making a vaccine," Beverley notes. "These new results may help us better direct the immune response toward long-term vaccination."

Michael C. Purdy | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Health and Medicine:

nachricht World first: Massive thrombosis removed during early pregnancy
20.07.2017 | Universitätsspital Bern

nachricht Therapy of preterm birth in sight?
19.07.2017 | Universitätsspital Bern

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: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>