Featured Research

from universities, journals, and other organizations

Minor Mutations In HIV Virus Have Major Impact

Date:
July 20, 2001
Source:
Massachusetts General Hospital
Summary:
Researchers at Massachusetts General Hospital (MGH) published a study in this week's Nature indicating that HIV can mutate key proteins in order to hide from an immune attack, and once these mutations occur they persist.

BOSTON - Researchers at Massachusetts General Hospital (MGH) published a study in this week's Nature indicating that HIV can mutate key proteins in order to hide from an immune attack, and once these mutations occur they persist.

"The virus is gradually evolving and learning how to evade the immune system," says the senior author of the study Bruce Walker, MD, of the Partners AIDS Research Center at MGH. "This study shows for the first time that minor mutations in the virus can have a major impact on the ability of the immune defenses to recognize it."

When HIV infects a cell, the cell alerts the immune system that it contains a foreign invader by displaying viral protein fragments on the cell surface. This is a suicide signal that alerts the immune system to kill the infected cell. The immune response that is generated is dependent on the ability to recognize the displayed HIV fragment. Walker and his colleagues have found that the virus can mutate these targeted regions and in doing so evade this attack.

"Our study indicates that the virus can learn how to evade the immune response in one person, and that it retains this ability even after it is transmitted to the next person," says Philip Goulder, MD, the lead author on the study. When this happens, the immune system is forced to use a second-line attack strategy that was less effective in containing the virus in the patients studied. These studies, which were performed in HIV-infected mothers who transmitted virus to their infants, showed that the infected infants are less able to control the virus because of mutations that occurred in the mothers. The effects of these mutations were particularly apparent in the children since they inherit key elements of their immune systems from their parents, and thus there is a strong chance that they will be programmed to target the same regions that the mother targeted. In mothers in whom mutations had already arisen, the children could not target the virus effectively.

The authors also examined adults who recently had been infected with HIV by sexual transmission, and found that the viruses presently being transmitted have already evolved to be able to avoid a number of important immune responses. Once these mutations arise, they do not appear to revert to the original strain, suggesting that escape mutations are likely to accumulate as the epidemic progresses.

The findings have significant implications for vaccines that are presently in development. "Vaccines being tested today are based on strains that were isolated a number of years ago, " says Walker. "These vaccines are attempting to induce immune responses to regions of the virus that may have already mutated, and thus the immune responses may be less effective." In the same way that influenza virus evolves to escape detection by immune responses and requires new vaccines to be made on a regular basis, HIV also is evolving. The extent to which this will affect present vaccine candidates is not known, but the present study indicates that this is something that will need to be monitored very closely.

The current work was supported by the Medical Research Council (UK), the NIH, the Doris Duke Charitable Foundation, the Lloyd Foundation and the Elizabeth Glaser Pediatric AIDS Foundation and a number of private donors.

The Massachusetts General Hospital, established in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospital-based research program in the United States, with an annual research budget of more than $300 million and major research centers in AIDS, the neurosciences, cardiovascular research, cancer, cutaneous biology, transplantation biology and photo-medicine. In 1994, the MGH joined with Brigham and Women's Hospital to form Partners HealthCare System, an integrated health care delivery system comprising the two academic medical centers, specialty and community hospitals, a network of physician groups and nonacute and home health services.


Story Source:

The above story is based on materials provided by Massachusetts General Hospital. Note: Materials may be edited for content and length.


Cite This Page:

Massachusetts General Hospital. "Minor Mutations In HIV Virus Have Major Impact." ScienceDaily. ScienceDaily, 20 July 2001. <www.sciencedaily.com/releases/2001/07/010720093730.htm>.
Massachusetts General Hospital. (2001, July 20). Minor Mutations In HIV Virus Have Major Impact. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2001/07/010720093730.htm
Massachusetts General Hospital. "Minor Mutations In HIV Virus Have Major Impact." ScienceDaily. www.sciencedaily.com/releases/2001/07/010720093730.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
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