Navigation Links
Study IDs protein that inhibits HIV from growing in cell cultures

How a harmless virus called GB Virus type C (GBV-C) protects against HIV infection is now better understood. Researchers at the Department of Veterans Affairs (VA) Iowa City Health Care System and the University of Iowa have identified a protein segment that strongly inhibits HIV from growing in cell models.

The team found that an 85-amino acid segment within a GBV-C viral protein called NS5A greatly slows down HIV from replicating in cells grown in labs. The study results will appear online this week in the Proceedings of the National Academy of Sciences.

The finding builds on earlier VA and UI work showing that people with HIV who also are infected GBV-C live longer than those infected only with HIV, said Jinhua Xiang, M.D., a VA research health scientific specialist, UI researcher and the current study's principal author.

GBV-C and its role in HIV infection have been studied for nearly a decade by Xiang, along with another study author Jack Stapleton, M.D., staff physician and researcher at the VA Iowa City Health Care System and professor of internal medicine at the UI Roy J. and Lucille A. Carver College of Medicine.

"Identifying a specific protein made by GBV-C that inhibits HIV growth in cell culture strengthens the argument that GBV-C is responsible for the prolonged survival observed in several studies of HIV-positive people," Xiang said. "Understanding how the protein works may allow us to develop target-specific therapies that can mimic these effects and inhibit HIV.

"Potentially these novel therapies would have certain advantages over current drugs, as the newer therapies would target the cell in which HIV can replicate and not the virus directly. Therefore, HIV should have more difficulty developing resistance to the effects of this protein," Xiang added.

Xiang previously discovered that GBV-C grows in the same type of white blood cells, CD4 T-cells, that HIV grows in and ultimately destroys. HI V attaches to this T-cell by first landing on a receptor called CD4. Once it reacts with the receptor, HIV can enter the cell, multiply and destroy the T-cell, thereby causing immune deficiency.

"People with GBV-C have a slower rate of destruction of these T-cells," said Stapleton, who also is director of the Division of Infectious Diseases at the Iowa City VA and UI.

The current study shows that the newly identified protein, NS5A, inhibits HIV in part by decreasing the number of CD4 receptors available to HIV. With fewer places for HIV to "dock," less HIV enters the cells to inflict destruction.

However, Xiang cautioned, this is only part of the story, and the researchers must continue work to understand how the NS5A protein exerts its total effect.

"Before NS5A can be used for any kind of therapy, we need to further map it," Xiang said. "We need to zero in to see what region has the critical effect on HIV inhibition."

Once that is accomplished, the team will seek to develop small molecular drugs that mimic the inhibiting action.

Stapleton noted that GBV-C is not toxic to T-cells and is not associated with any human disease. As a result, the U.S. Food and Drug Administration does not require that blood donations be screened for this common virus.

Up to 3 percent of healthy blood donors in the United States have active GBV-C infection. An additional 12 percent have antibodies indicating past exposure at the time of donation. Because the GBV-virus is transmitted through bodily fluids, as is HIV, many HIV-positive individuals have evidence of past or present infection with GBV-C.

Stapleton and Xiang first began studying the GBV-C and HIV connection because they were skeptical of earlier studies published in the mid-1990s.

"It was a strange story," Stapleton said. "Who would have thought a virus floating around in a lot of people does not make them sick but could significantly influence survival in people with HIV?"


'"/>

Source:University of Iowa


Related biology news :

1. Novel Asthma Study Shows Multiple Genetic Input Required; Single-gene Solution Shot Down
2. Emory Study Tests Bone Marrow Stem Cells to Improve Circulation in Legs
3. UCLA Study Shows One-Third of Drug Ads in Medical Journals Do Not Contain References Supporting Medical Claims
4. Study Demonstrates Gene Expression Microarrays are Comparable and Reproducible
5. Study Links Ebola Outbreaks To Animal Carcasses
6. Breakthrough Microarray-based Technology for the Study of Cancer
7. NYU Study Reveals How Brains Immune System Fights Viral Encephalitis
8. Study finds more than one-third of human genome regulated by RNA
9. Leukemia Drug Breakthrough Study In New England Journal Of Medicine
10. Study identifies predictors of HIV drug resistance in patients beginning triple therapy
11. New Study from Affymetrix Laboratories Points to Changing View of How Genome Works
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/14/2016)... , Allemagne, March 14, 2016 ... ) - --> - Renvoi : image ... --> --> ... biométriques, fournit de nouveaux lecteurs d,empreintes digitales pour ... de DERMALOG sera utilisé pour produire des cartes ...
(Date:3/10/2016)... 10, 2016   Unisys Corporation (NYSE: UIS ... (CBP) is testing its biometric identity solution at the ... to help identify certain non-U.S. citizens leaving the country. ... designed to help determine the efficiency and accuracy of using ... and will run until May 2016. --> ...
(Date:3/8/2016)... March 8, 2016   Valencell , the ... announced it has secured $11M in Series D ... a new venture fund being launched by UAE-based ... from existing investors TDF Ventures and WSJ Joshua ... continue its triple-digit growth and accelerate its pioneering ...
Breaking Biology News(10 mins):
(Date:5/25/2016)... ... May 25, 2016 , ... ... delegation at BIO 2016 in San Francisco. Located at booth number 7301, representatives ... to answer questions and discuss the Thai biotechnology and life sciences sector. ...
(Date:5/25/2016)... ... 25, 2016 , ... Scientists at the University of Athens say they have ... be hampering the research that could lead to one good one. Surviving Mesothelioma has ... now. , The team evaluated 98 mesothelioma patients who got a ...
(Date:5/24/2016)... ... May 24, 2016 , ... Cell ... injuries, will be accelerated by research at Worcester Polytechnic Institute (WPI) that yielded ... healing and tissue regeneration. , The novel method, developed by WPI faculty members ...
(Date:5/23/2016)... ... ... The need for blood donations in South Texas and across the nation is growing. , ... Center, blood donations are on the decline. In fact, donations across the country are at ... South Texas in the last four years alone. , There is no substitute for blood. ...
Breaking Biology Technology: