Featured Research

from universities, journals, and other organizations

HIV Uses Autophagy For Its Own Means

Date:
July 29, 2009
Source:
Rockefeller University Press
Summary:
Not satisfied with simply thwarting its host's defensive maneuvers, HIV actually twists one to its advantage, based on new findings. Researchers suggest that autophagy -- a stress response process -- helps HIV to proliferate and that conversely, blocking autophagy lessens HIV production.

Kyei et al. found that the HIV Gag protein (green) localized to autophagosomes (red). Another HIV protein, Nef, blocks the later stages of autophagosome maturation to allow full Gag processing and increase viral yield.
Credit: Kyei, G.B., et al. 2009. J. Cell Biol. doi:10.1083/jcb.200903070

Not satisfied with simply thwarting its host's defensive maneuvers, HIV actually twists one to its advantage, based on new findings from Kyei et al. in the July 27, 2009 issue of the Journal of Cell Biology. Vojo Deretic and colleagues suggest that autophagy—a stress response process—helps HIV to proliferate and that conversely, blocking autophagy lessens HIV production.

Reduced HIV levels were accompanied by a blockade in the processing of Gag—a key precursor protein for HIV assembly. Gag in fact localized to complexes containing an autophagy protein, LC3. "It looked paradoxical," says Deretic. "But only if you didn't know something else. And that is a finding in yeast that autophagy is not only degradative, but can also serve in some biosynthetic pathways," including the trafficking of the Cvt protein to the vacuole. Together, the results suggest that Gag may piggyback on autophagosomes or their components, perhaps for locomotive services, to complete its maturation.

The group then sought the viral agitator that blocks autophagosome maturation and allows Gag processing. Their primary candidate was HIV protein Nef, which interacts with the vacuolar proton ATPase and might thereby block acidification steps necessary to make a degradative organelle. Using a mutant virus, the group showed that HIV lacking Nef no longer profited from increased autophagy and was instead degraded. It is not yet clear exactly how Nef blocks autophagosome maturation.

Clinical applications may be far down the road. If the idea is to kill the virus using drugs such as rapamycin, which induces autophagy, it will first be necessary to block Nef, notes Deretic. The idea is not without natural support. "There were cases in Australia involving HIV strains that lacked Nef," he says. "And these people would not progress to AIDS, meaning the virus is disabled."

Deretic has other exciting ideas. Highly active anti-retroviral therapy often does a smashing job clearing viral loads from the blood. But the pathogen can persist in particular locales such as gut lymphoid tissue. "My hope," says Deretic, "is to go after these reservoirs and chew up the virus that for some reason is not readily accessible or susceptible to the anti-retroviral therapy. I have great hope that autophagy will help us with that. This is something we didn't have on our radar screens just five years ago."

Reference: Kyei, G.B., et al. 2009. J. Cell Biol. doi:10.1083/jcb.200903070.


Story Source:

The above story is based on materials provided by Rockefeller University Press. Note: Materials may be edited for content and length.


Cite This Page:

Rockefeller University Press. "HIV Uses Autophagy For Its Own Means." ScienceDaily. ScienceDaily, 29 July 2009. <www.sciencedaily.com/releases/2009/07/090727091834.htm>.
Rockefeller University Press. (2009, July 29). HIV Uses Autophagy For Its Own Means. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2009/07/090727091834.htm
Rockefeller University Press. "HIV Uses Autophagy For Its Own Means." ScienceDaily. www.sciencedaily.com/releases/2009/07/090727091834.htm (accessed October 21, 2014).

Share This



More Health & Medicine News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
CDC Issues New Ebola Guidelines for Health Workers

CDC Issues New Ebola Guidelines for Health Workers

Reuters - US Online Video (Oct. 21, 2014) The U.S. Centers for Disease Control and Prevention has set up new guidelines for health workers taking care of patients infected with Ebola. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins