Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study shows why some immune systems control HIV

07.10.2002


Scientists are beginning to change their thinking about why the immune systems of most people infected with HIV cannot control the spread of the virus while the immune systems of a rare group of individuals, called long-term nonprogressors, can. For some time, scientists thought that people who could not control HIV had too few HIV-fighting white blood cells called CD8+ T cells. However, a new study suggests the difference is not the number but the quality of these cells: both nonprogressors and others have about the same number of HIV-fighting CD8+ T cells, but the cells of nonprogressors function better.



"Understanding the mechanisms by which the immune systems of long-term nonprogressors control HIV is important to our development of effective vaccines," says Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID). "Studies like this one, which reveal basic knowledge about how the immune system interacts with HIV, form the foundation of our effort to fight this disease." Details of the study, conducted by NIAID scientists, will appear on October 7 in the advanced online issue of Nature Immunology.

Instead of attacking HIV directly, CD8+ cells inhibit virus spread by killing off other immune system cells infected with HIV. "For some time we have known that even patients who cannot control HIV maintain high numbers of HIV-specific CD8+ T cells," says senior author Mark Connors, M.D., of NIAID’s Laboratory of Immunoregulation. However, this study represents the first time scientists have observed a difference in the HIV-specific CD8+ T-cell response of nonprogressors, he says. This study also suggests a mechanism whereby the CD8+ T cells of nonprogressors control HIV and those of most individuals do not.


Dr. Connors and colleagues closely examined the immune systems of 40 people infected with HIV, including a group of about 15 nonprogressors - people who have controlled HIV for up to 20 years without antiretroviral therapy. The researchers found no significant difference in the number of HIV-fighting CD8+ cells between nonprogressors and the others. Instead, the scientists found that the nonprogressors’ cells were better able to divide and proliferate when called on to go into action; they also produced higher levels of a molecule called perforin, which helps them to kill off cells infected with HIV.

"Some of the newer techniques used in this study enabled us to see the functional differences in the CD8+ T cells of the two groups," says lead author Stephen Migueles, M.D., also at NIAID’s Laboratory of Immunoregulation. "The CD8+ T cells of people in the study who did not control HIV had retained only a limited ability to divide and produce perforin."

This finding is especially important to HIV vaccine research efforts, says Dr. Connors, because many candidate HIV vaccines attempt to induce a strong CD8+ T cell response. New knowledge about CD8+ T-cell function opened up by this line of research might lead to preventive vaccines that avoid the development of poorly functioning CD8+ T cells. In addition, this research might lead to therapeutic vaccines for HIV-infected people that improve the function of their CD8+ T cells and control HIV infection.

Next, Dr. Connors and colleagues plan to analyze an even broader array of differences between the CD8+ T cells of nonprogressors and others infected with HIV, seeking to understand what causes the poor function of most HIV-infected people’s CD8+ T cells.


NIAID is a component of the National Institutes of Health (NIH). NIAID supports basic and applied research to prevent, diagnose, and treat infectious and immune-mediated illnesses, including HIV/AIDS and other sexually transmitted diseases, illness from potential agents of bioterrorism, tuberculosis, malaria, autoimmune disorders, asthma and allergies.

Jeff Minerd | EurekAlert!

More articles from Health and Medicine:

nachricht Custom-tailored strategy against glioblastomas
26.09.2016 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht New leukemia treatment offers hope
23.09.2016 | King Abdullah University of Science and Technology

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: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Paper – Panacea Green Infrastructure?

30.09.2016 | Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

 
Latest News

Cells migrate collectively by intermittent bursts of activity

30.09.2016 | Life Sciences

The structure of the BinAB toxin revealed: one small step for Man, a major problem for mosquitoes!

30.09.2016 | Life Sciences

Researcher creates a controlled rogue wave in realistic oceanic conditions

30.09.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>