Featured Research

from universities, journals, and other organizations

Study Suggests Possibility Of Universally Effective AIDS Vaccine

Date:
October 31, 1997
Source:
Massachusetts General Hospital
Summary:
A study from the Massachusetts General Hospital suggests that it may be possible to develop an AIDS vaccine effective against all versions of the virus. In the November Journal of Virology, the researchers report that the immune system's killer cells are capable of recognizing different strains of the human immunodeficiency virus.

A study by a research team based at the Massachusetts General Hospital (MGH) suggests that it may be possible to develop an AIDS vaccine that will be effective against the different versions of the virus found around the world.

As reported in the November issue of the Journal of Virology, the researchers found that the immune system's killer cells, called cytotoxic T-lymphocytes (CTLs), are capable of recognizing different strains, or clades, of the human immunodeficiency virus (HIV). In the past it has been feared that the prevalence of different HIV strains in different parts of the world would require developing different vaccines targeted to each strain.

CTLs have become the focus of HIV vaccine research in recent years, as earlier vaccine strategies based on the activity of antibodies have not proven successful. The immune system teaches these killer cells to target a specific type of virus, bacteria or other foreign material. Cells targeted to a specific virus seek out and destroy virally infected cells by recognizing peptides — small fragments of the proteins that make up that virus — that are displayed on cell surfaces.

CTLs are not infected by HIV and usually mount a defense against the virus soon after the initial infection. In most patients, however, the levels of CTLs eventually decrease, allowing HIV levels to rise and AIDS symptoms to develop. Recent research has produced evidence that CTL activity is likely to be be a key immune response against HIV. High CTL levels have been seen in long-term nonprogressors — individuals who remain healthy despite being infected for many years — and CTLs that target the virus have been found in people who remain uninfected despite many exposures to HIV. In addition, CTLs seem to play an important role in the immune response against other viral disease, like cytomegalovirus and Epstein-Barr virus.

"There really is a growing consensus in the field that generating a strong, virus-specific CTL response will be important in developing any successful vaccine against HIV," says Bruce Walker, MD, director of the Partners AIDS Research Center based at the MGH and senior author of the report. "Since those parts of world most affected by this disease do not have the resouces to take full advantage of current therapies, a vaccine is the only way we're going to be able to eliminate AIDS globally."

Most HIV-infected individuals in the United States and Europe are infected with clade B, while several other clades — the most common are A, C, D and E — predominate in Africa and Asia. The researchers tested CTLs taken from indivi duals infected with clade B HIV and tested whether they would recognize viral peptides from all of the major clades. All of the tested CTLs recognized peptides from at least one non-B clade virus, and most reacted against peptides from all clades tested. The team also tested CTLs from 14 infected individuals from Senegal, 10 of whom were infected with clade A virus, three with clade G and one with clade C. CTLs from all 14 individuals reacted against proteins from clade B viruses.

"We were very surprised to see this striking amount of CTL cross-reactivity," says Walker. "But this result is supported by previous observations that people infected with one strain seem be protected against other strains of HIV."

Walker notes that CTL-based vaccines are just beginning to be tested in human volunteers, and many questions remain to be answered. For instance, it is far from certain whether CTL activity alone would be sufficient to protect against either HIV infection or progression to AIDS. Future studies are needed to define exactly which immune system responses will be most important for protection against HIV.

Walker's coauthors include Huyen Cao, MD, first author, and Spyros Kalams, MD, from the MGH; Phyllis Kanki, DVM, Jean-Louis Sankale, MD, and Abdoulaye Dieng-Sarr, of the Department of Cancer Biology at Harvard School of Public Health; Gail Mazzara, PhD, of Therion Biologic Corporation in Cambridge; Bette Korber, PhD, of the Los Alamos National Laboratory in New Mexico; and Souleymane Mboup, MD, of University Cheikh Anto Diop in Dakar, Senegal. The research was supported by grants from the National Institutes of Health.


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. "Study Suggests Possibility Of Universally Effective AIDS Vaccine." ScienceDaily. ScienceDaily, 31 October 1997. <www.sciencedaily.com/releases/1997/10/971031075015.htm>.
Massachusetts General Hospital. (1997, October 31). Study Suggests Possibility Of Universally Effective AIDS Vaccine. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/1997/10/971031075015.htm
Massachusetts General Hospital. "Study Suggests Possibility Of Universally Effective AIDS Vaccine." ScienceDaily. www.sciencedaily.com/releases/1997/10/971031075015.htm (accessed September 20, 2014).

Share This



More Health & Medicine News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sierra Leone's Nationwide Ebola Curfew Underway

Sierra Leone's Nationwide Ebola Curfew Underway

Newsy (Sep. 20, 2014) Sierra Leone is locked down as aid workers and volunteers look for new cases of Ebola. Video provided by Newsy
Powered by NewsLook.com
Changes Found In Brain After One Dose Of Antidepressants

Changes Found In Brain After One Dose Of Antidepressants

Newsy (Sep. 19, 2014) A study suggest antidepressants can kick in much sooner than previously thought. Video provided by Newsy
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) 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:
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