Featured Research

from universities, journals, and other organizations

HIV protein unveils vaccine target

Date:
April 1, 2011
Source:
University of California - Davis
Summary:
A new study describes how a component of a potential HIV vaccine opens like a flower, undergoing one of the most dramatic protein rearrangements yet observed in nature. The finding could reveal new targets for vaccines to prevent HIV infection and AIDS.

This side view of the HIV envelope protein shows a virus (bottom) and a T cell (top). The mesh shows its normal shape, the green/red/blue shading shows its changed shape.
Credit: R. Holland Cheng/UC Davis graphic

An international study headed by a UC Davis scientist describes how a component of a potential HIV vaccine opens like a flower, undergoing one of the most dramatic protein rearrangements yet observed in nature. The finding could reveal new targets for vaccines to prevent HIV infection and AIDS. A paper describing the work was published online in the Proceedings of the National Academy of Sciences.

In the new study, researchers from the U.S., Sweden and France explored the structure and behavior of the HIV envelope protein complex, which could potentially serve as a component of a vaccine aimed at eliciting the human immune system to generate antibodies against HIV.

"By opening up these less exposed regions, we might be able to raise more broadly cross-reactive antibodies to HIV," said R. Holland Cheng, professor of molecular and cellular biology at UC Davis and senior author of the study.

HIV infects a type of white blood cell called the CD4 T cell, weakening the immune system and leading to AIDS. HIV attaches to these cells through the envelope protein complex, which is made up of three gp120 proteins and three gp41 proteins, Cheng said.

First, the gp120 protein attaches to a CD4 protein on the victim cell's membrane. Then it uses gp41 to punch a hole through the membrane.

UC Davis graduate student Carlos Moscoso and project scientist Li Xing, working in Cheng's laboratory, used a cryoelectron microscope to study the structure of the complex and how it changes when it is exposed to a piece of the CD4 protein. A cryoelectron microscope derives three-dimensional images of complex protein structures from samples frozen in liquid nitrogen.

They found that when the HIV protein complex attaches to a CD4 protein, it rotates and flattens, exposing more of the gp41 proteins in the middle -- probably allowing the gp41 protein to get closer to the cell membrane so it can lock on.

It also potentially exposes an area of the virus that would be vulnerable to attack by the immune system, Cheng said. If a person were vaccinated and had antibodies to such a protein region, they might be able to stop the virus at the point of invading the CD4 T cell.

The gp120 protein itself varies considerably between strains, so it has been difficult to make an effective vaccine against it. But these hidden protein regions vary less between different strains of HIV, Cheng said.

Cheng's group is part of the HIV Research and Design consortium formed by the National Institutes of Health to pursue new targets for HIV vaccines. In future work, the consortium plans to test potent antibodies from HIV-positive people who have survived without developing AIDS to see if the antibodies recognize the new potential vaccine targets.

The envelope protein complex was prepared by Novartis Diagnostics and Vaccines Inc. of Cambridge, Mass.

The other authors of the paper are: Selina Poon, Dominik Green and Frank Lin at the Department of Molecular and Cellular Biology, UC Davis; Yide Sun, Elaine Kan, Susan Barnett and Indresh Srivastava, at Novartis; Loοc Martin, Commissariat ΰ l'Ιnergie Atomique, France; and Anders Vahlne, Karolinska Institute, Sweden.

The work was funded by the NIH.


Story Source:

The above story is based on materials provided by University of California - Davis. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. G. Moscoso, Y. Sun, S. Poon, L. Xing, E. Kan, L. Martin, D. Green, F. Lin, A. G. Vahlne, S. Barnett, I. Srivastava, R. H. Cheng. Quaternary structures of HIV Env immunogen exhibit conformational vicissitudes and interface diminution elicited by ligand binding. Proceedings of the National Academy of Sciences, 2011; DOI: 10.1073/pnas.1016113108

Cite This Page:

University of California - Davis. "HIV protein unveils vaccine target." ScienceDaily. ScienceDaily, 1 April 2011. <www.sciencedaily.com/releases/2011/03/110331094626.htm>.
University of California - Davis. (2011, April 1). HIV protein unveils vaccine target. ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2011/03/110331094626.htm
University of California - Davis. "HIV protein unveils vaccine target." ScienceDaily. www.sciencedaily.com/releases/2011/03/110331094626.htm (accessed April 24, 2014).

Share This



More Health & Medicine News

Thursday, April 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) — Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
Study Says Most Crime Not Linked To Mental Illness

Study Says Most Crime Not Linked To Mental Illness

Newsy (Apr. 22, 2014) — A new study finds most crimes committed by people with mental illness are not caused by symptoms of their illness or disorder. Video provided by Newsy
Powered by NewsLook.com
Hagel Gets Preview of New High-Tech Projects

Hagel Gets Preview of New High-Tech Projects

AP (Apr. 22, 2014) — Defense Secretary Chuck Hagel is given hands-on demonstrations Tuesday of some of the newest research from DARPA _ the military's Defense Advanced Research Projects Agency program. (April 22) Video provided by AP
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) — NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. Video provided by Newsy
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:
from the past week

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