Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New avenue of HIV damage found

10.10.2002


Researchers at the University of Minnesota have discovered a new process by which HIV damages the immune system. They demonstrated that the portion of lymph nodes called the T cell zone is significantly damaged by chronic inflammation, which causes fibrosis. This is important because the T cell zone is where a significant portion of the human immune response occurs. The finding of accumulation of scar tissue in this portion of the lymph node may explain why aggressive anti-retroviral therapy (ART) does not improve the immune system in some people with HIV-1 infection. The study findings will be published in the Oct. 16, 2002, issue of the Journal of Clinical Investigation. The paper can be found at www.jci.org.



"HIV infection ultimately depletes the body of CD4 T cells, making it impossible to mount an immune response," said Timothy W. Schacker, M.D., associate professor of medicine and author of the study. "For the first time, we show that one mechanism of this depletion is damage to the structure that these cells need to maintain a normal-sized population and to mount an immune response to other infections. In essence, the T cell home is destroyed."

Researchers enrolled 11 individuals at various stages of HIV/AIDS infection. Their goal was to understand the specific changes that happen in the population of cells most directly affected by HIV--the CD4 T cells. These cells are responsible for coordinating the immune response and are the primary target for HIV infection and replication. Researchers biopsied and examined the lymph node tissue before and during treatment for HIV. They have developed sensitive methods to precisely measure both the size of the CD4 population in lymphatic tissue and the amount of scar tissue accumulated in the T cell zone.


Researchers noted two significant findings. First, the size of the CD4 T cell population measured in peripheral blood (commonly done to stage the disease and determine the effects of treatment) does not accurately reflect the size of the population in lymph tissues. "You could have a reasonable peripheral count and a very poor count in lymph tissues," said Schacker.

Second, the amount of fibrosis and scar tissue in the T cell zone was significantly related to the size of the CD4 population in that space (i.e. the more scar tissue, the fewer cells) and the recovery of the CD4 population with therapy. The researchers suggest the process of destruction is analogous to what is seen in chronic active hepatitis.

"We knew that T cells are destroyed by direct viral replication," said Schacker, "but we now know that the population is unable to recover to a normal size because the environmental niche used to support the cells is destroyed. New CD4 T cells are unable to get into the space they need to be in to function, and there is no space for the cells to divide."

One implication of this discovery is that through testing of the lymph nodes (similar to what is done to stage cancer), physicians might accurately stage the disease and predict the response to standard therapies.

"This is essentially a new concept in how HIV infection causes damage to the human immune system," said Schacker. "Our observation may explain why up to 25 percent of people placed on HIV therapy may have good viral suppression but still have no significant increase in T cell count.

"Currently, most treatment strategies for HIV/AIDS focus on stopping the virus from replicating itself in the body, which is essential to begin the process of immune reconstitution, but it does not happen for everyone. These findings suggest that therapies targeting the damage from inflammation and accumulation of scar tissue might enhance current antiviral therapy."

Deane Morrison | EurekAlert!
Further information:
http://www.umn.edu/

More articles from Health and Medicine:

nachricht Foods of the future
15.08.2018 | Georg-August-Universität Göttingen

nachricht New antibody analysis accelerates rational vaccine design
09.08.2018 | Scripps Research Institute

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: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Unraveling the nature of 'whistlers' from space in the lab

15.08.2018 | Physics and Astronomy

Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide

15.08.2018 | Earth Sciences

Early opaque universe linked to galaxy scarcity

15.08.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>