Featured Research

from universities, journals, and other organizations

Promising HIV Vaccine Strategy Identified In Monkey Studies

Date:
September 21, 2000
Source:
National Institute Of Allergy And Infectious Diseases
Summary:
Vaccines designed to trigger an immune response to a small HIV protein called Tat could be a promising way to fend off the virus, intriguing new data suggest. According to a report in this week's journal Nature, "killer" T cells targeted to the Tat protein can effectively contain simian immunodeficiency virus (SIV), the monkey version of HIV, during the natural course of early infection.

Vaccines designed to trigger an immune response to a small HIV protein called Tat could be a promising way to fend off the virus, intriguing new data suggest. According to a report in this week's journal Nature, "killer" T cells targeted to the Tat protein can effectively contain simian immunodeficiency virus (SIV), the monkey version of HIV, during the natural course of early infection.

University of Wisconsin researchers found that these Tat-specific killer T cells eliminated the original strain of SIV four weeks after they exposed rhesus macaque monkeys to the virus. The monkeys still had some SIV, but this SIV differed genetically from the original strain. These small genetic changes, pinpointed by the research team and traced predominantly to the Tat protein, provided enough disguise to enable the virus to escape immune attack.

"These animal studies open the window on immune events in early HIV infection and provide a rationale for exploring a new approach to designing HIV vaccines," says Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID), which funded the research. "The results suggest that using vaccines that stimulate immune responses against virus proteins produced within a few hours after infection, such as Tat, may help control HIV."

"This is the first time someone has investigated the entire cellular immune response during the acute phase of infection," adds Peggy Johnston, Ph.D., NIAID's assistant director for AIDS vaccines and associate director of the Vaccine and Prevention Research Program in the Institute's Division of AIDS. The cellular immune response primarily consists of killer T cells, which attack infected cells rather than target free virus. "If ongoing work by these investigators shows that vaccinating monkeys with SIV Tat induces a massive killer T-cell response that can prevent infection or substantially reduce the amount of virus in monkeys, research on HIV vaccines that incorporate similar targets will be stimulated." Current products in human vaccine trials primarily induce immune responses to envelope or other structural proteins of HIV rather than to functional proteins like Tat, which is required for the virus to replicate.

Virus levels peak within weeks after both HIV and SIV infection, but decline soon after when strong killer T-cell responses develop. These responses, however, can hold the virus at bay only so long, eventually losing out to the virus. The power struggle shifts in favor of the virus, the Wisconsin researchers found, because killer T cells pressure the virus to evolve or be destroyed. The challenge remains to design vaccines that induce killer T-cell responses so that the immune system retains the power.

Patricia D'Souza, Ph.D., a microbiologist with NIAID's Division of AIDS and project officer for this study, says cellular immune responses to HIV and SIV have been difficult to investigate, and only recent research developments made this work possible. "Without the availability of genetically typed monkeys, cloned virus and innovative technology in cellular immunity, it would have been impossible for Dr. Watkin's group to detect this massive, early Tat-specific immune response."

The study team, led by professor of pathology and laboratory medicine David Watkins, Ph.D., Todd Allen, Ph.D., and graduate student David O'Connor, conducted the research at the Wisconsin Regional Primate Research Center (RPRC) in Madison. This RPRC is one of eight centers located nationwide that is funded by the National Center for Research Resources, part of the National Institutes of Health (NIH).

NIAID is a component of NIH. NIAID supports basic and applied research to prevent, diagnose and treat infectious and immune-mediated illnesses, including HIV/AIDS and other sexually transmitted diseases, tuberculosis, malaria, autoimmune disorders, asthma and allergies.

###

References: 1)TM Allen et al. Tat-specific cytotoxic T lymphocytes select for SIV escape variants during resolution of primary viremia. Nature 407:386-90 (2000). 2)BD Walker and PJR Goulder. Escape from the immune system. Nature 407:313-14 (2000).

Press releases, fact sheets and other NIAID-related materials are available via the NIAID home page at http://www.niaid.nih.gov. For additional information on the Regional Primate Research Centers, contact Kathy Kaplan, Information Officer, National Center for Research Resources, 301-435-0888 or visit the NCRR Web site at http://www.ncrr.nih.gov.


Story Source:

The above story is based on materials provided by National Institute Of Allergy And Infectious Diseases. Note: Materials may be edited for content and length.


Cite This Page:

National Institute Of Allergy And Infectious Diseases. "Promising HIV Vaccine Strategy Identified In Monkey Studies." ScienceDaily. ScienceDaily, 21 September 2000. <www.sciencedaily.com/releases/2000/09/000920150846.htm>.
National Institute Of Allergy And Infectious Diseases. (2000, September 21). Promising HIV Vaccine Strategy Identified In Monkey Studies. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2000/09/000920150846.htm
National Institute Of Allergy And Infectious Diseases. "Promising HIV Vaccine Strategy Identified In Monkey Studies." ScienceDaily. www.sciencedaily.com/releases/2000/09/000920150846.htm (accessed July 30, 2014).

Share This




More Health & Medicine News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Generics Eat Into Pfizer's Sales

Generics Eat Into Pfizer's Sales

Reuters - Business Video Online (July 29, 2014) Pfizer, the world's largest drug maker, cut full-year revenue forecasts because generics could cut into sales of its anti-arthritis drug, Celebrex. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Nigeria Ups Ebola Stakes on 1st Death

Nigeria Ups Ebola Stakes on 1st Death

Reuters - Business Video Online (July 29, 2014) Nigerian authorities have shut and quarantined a Lagos hospital where a Liberian man died of the Ebola virus, the first recorded case of the highly-infectious disease in Africa's most populous economy. David Pollard reports Video provided by Reuters
Powered by NewsLook.com
Running 5 Minutes A Day Might Add Years To Your Life

Running 5 Minutes A Day Might Add Years To Your Life

Newsy (July 29, 2014) According to a new study, just five minutes of running or jogging a day could add years to your life. Video provided by Newsy
Powered by NewsLook.com
Ebola Outbreak Poses Little Threat To U.S.: CDC

Ebola Outbreak Poses Little Threat To U.S.: CDC

Newsy (July 29, 2014) The Ebola outbreak in West Africa poses little threat to Americans, according to officials with the Centers for Disease Control and Prevention. 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