Featured Research

from universities, journals, and other organizations

Slowing down immune system's 'brakes' may improve HIV vaccines

Date:
March 29, 2010
Source:
University of Pittsburgh Schools of the Health Sciences
Summary:
Like a skittish driver slamming the brakes, a special class of T cells may be limiting the effectiveness of therapeutic vaccines for HIV by slowing the immune system response too soon, report health science researchers. Their study may help researchers improve the efficacy of such vaccines by devising methods to circumvent the braking mechanism of these cells.

Like a skittish driver slamming the brakes, a special class of T cells may be limiting the effectiveness of therapeutic vaccines for HIV by slowing the immune system response too soon, report University of Pittsburgh health science researchers in the current issue of PLoS ONE. Their study, the first to look at the role of regulatory T cells in therapeutic HIV vaccines, may help researchers improve the efficacy of such vaccines by devising methods to circumvent the braking mechanism of these cells.

Related Articles


Regulatory T cells (Treg) are critical because they prevent the immune system from turning against itself by suppressing the immune response. Without the braking action of Treg, autoimmune disease could flourish. But what if these cells are shutting down the immune response before a therapeutic vaccine has had a chance to bolster immunity against HIV?

Pitt researchers sought to answer this question as follow-up to a clinical trial of a therapeutic dendritic cell-based HIV vaccine they developed to activate the CD8, or killer T cell, response. First reported in 2008, their findings indicated only limited success of the vaccine in the 17 patients enrolled in the trial. For the current study, the researchers went back to the freezer, removed Treg from the patients' blood cell samples and found it was masking a two-fold increase in immune response to HIV induced by the vaccine.

"When we removed Treg from blood cells, we found a much stronger immune response to the vaccine, giving us insight into how we can develop more effective HIV vaccines," said Charles R. Rinaldo, Jr., Ph.D., professor and chairman, Department of Infectious Diseases and Microbiology, Pitt's Graduate School of Public Health and the study's senior author. "Treg normally shuts down CD8 responses once the infection has been controlled, but in this case it appears to be putting on the brakes early and possibly limiting the vaccine's ability to do its job effectively."

One theory is that HIV-infection drives up Treg, which in turn shuts down the HIV-1- specific CD8 T cell response, he said.

"We know how to treat HIV, but are still learning how to use immunotherapy strategies to completely flush it out of the body," added Bernard J.C. Macatangay, M.D., assistant director, University of Pittsburgh Immunology Specialty Laboratory and the study's lead author. "Our findings show Treg plays an important role, but we need to figure out how to maintain the right balance by getting around these cells without blocking them completely."

In addition to Drs. Rinaldo and Macatangay, authors of the study include Marta E. Szajnik, M.D., Ph.D., and Theresa Whiteside, Ph.D., University of Pittsburgh Cancer Institute; and Sharon Riddler, M.D., University of Pittsburgh School of Medicine. The research was supported by the National Institute of Allergy and Infectious Diseases.


Story Source:

The above story is based on materials provided by University of Pittsburgh Schools of the Health Sciences. Note: Materials may be edited for content and length.


Cite This Page:

University of Pittsburgh Schools of the Health Sciences. "Slowing down immune system's 'brakes' may improve HIV vaccines." ScienceDaily. ScienceDaily, 29 March 2010. <www.sciencedaily.com/releases/2010/03/100325113427.htm>.
University of Pittsburgh Schools of the Health Sciences. (2010, March 29). Slowing down immune system's 'brakes' may improve HIV vaccines. ScienceDaily. Retrieved November 24, 2014 from www.sciencedaily.com/releases/2010/03/100325113427.htm
University of Pittsburgh Schools of the Health Sciences. "Slowing down immune system's 'brakes' may improve HIV vaccines." ScienceDaily. www.sciencedaily.com/releases/2010/03/100325113427.htm (accessed November 24, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, November 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) A new study links greater authority with increased depressive symptoms among women in the workplace. Video provided by Newsy
Powered by NewsLook.com
Winter Can Cause Depression — Here's How To Combat It

Winter Can Cause Depression — Here's How To Combat It

Newsy (Nov. 23, 2014) Millions of American suffer from seasonal depression every year. It can lead to adverse health effects, but there are ways to ease symptoms. Video provided by Newsy
Powered by NewsLook.com
Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

AFP (Nov. 23, 2014) The arable district of Kenema in Sierra Leone -- at the centre of the Ebola outbreak in May -- has been under quarantine for three months as the cocoa harvest comes in. Duration: 01:32 Video provided by AFP
Powered by NewsLook.com
Don't Fall For Flu Shot Myths

Don't Fall For Flu Shot Myths

Newsy (Nov. 23, 2014) Misconceptions abound when it comes to your annual flu shot. Medical experts say most people older than 6 months should get the shot. 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:

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