Featured Research

from universities, journals, and other organizations

New way HIV infects women discovered

Date:
April 9, 2010
Source:
McMaster University
Summary:
Scientists have been puzzled as to how HIV finds its way into the female reproductive tract. The culprit could be HIV itself and what the virus does when it binds to epithelial cells.

Women are susceptible to HIV, the virus that causes AIDS, but scientists have been puzzled as to how it finds its way into the female reproductive tract.

Related Articles


One theory has been that trauma, such as a little tear during intercourse, causes HIV to cross epithelial cells -- the protective barrier that keeps out infection. There is also the suggestion an unknown mechanism is at work.

For the first time, researchers at McMaster University have discovered the culprit could be HIV itself and what the virus does when it binds to epithelial cells.

"What it does is that it makes the electrical barrier resistance of epithelial cells decrease. By doing that, the virus can cross the barrier," said lead researcher Charu Kaushic, associate professor in the Centre for Gene Therapeutics and the department of pathology and molecular medicine in the Michael G. DeGroote School of Medicine. She is also a researcher with the Michael G. DeGroote Institute of Infectious Disease Research.

"This is a significant step forward in defining where prevention strategies, such as microbicides and vaccine, need to focus. Instead of trying to stop HIV from infecting the target cells underneath the epithelium, we need to think about ways to stop the virus from attaching to epithelial cells themselves."

The study, which appears in the journal PLoS Pathogens, shows HIV can break down the mucosal barrier in the intestinal and female genital tract, allowing the virus to cross during intercourse.

The breakdown appears to be due to inflammatory factors produced by epithelial cells themselves, in response to HIV. This destroys the tight junctions between epithelial cells and gives HIV and other microbes access to inside the body, the researchers said.

Worldwide, half of the 40 million people infected with HIV are women. Among heterosexuals, women are the fastest growing group to be infected.

Scientists have been faced with the question of how HIV actually gets underneath epithelial cells to infect other cells that are susceptible to HIV. "It's not the cells on top," Kaushic said. "It is the immune cells underneath that have all the receptors that HIV likes to latch on to and that allow the virus to replicate and establish infection. But it has to cross the epithelial barrier first!"

The McMaster researchers grew purified primary epithelial cells in the laboratory from small pieces of tissues that were removed from women's uterus during hysterectomies, with their consent. Then, they began to study how HIV actually interacts with these cells. The electrical resistance in these cultures is used to monitor how well the epithelial cell cultures are growing and functioning.

Aisha Nazli, a researcher in Kaushic's laboratory, noticed every time she put HIV on epithelial cells their resistance went down significantly. Repeated tests confirmed this.

Kaushic said the surface protein of the virus causes the epithelial barrier to break. "The surface protein signals to the inside of the epithelial cells by binding to it," she said. "The epithelial cells start making inflammatory proteins which cause these cells to go on their self-destructive pathway."

Kaushic's lab conducted the research in collaboration with researchers in the department of molecular genetics at the University of Toronto and the department of medical biology at Laval University. She holds a New Investigator Award in HIV from the Canadian Institutes of Health Research (CIHR) and an Early Researcher's Award from the Ontario government.

The research was funded by Ontario HIV Treatment Network and an Emerging HIV Team Grant from CIHR.

"New prevention strategies are essential to changing the course of the HIV epidemic," said Dr. Marc Ouellette, Scientific Director of the Canadian Institutes of Health Research's Institute of Infection and Immunity, "this is an important finding that will influence HIV prevention research moving forward. We are very pleased to see that strategic investments of our HIV/AIDS Research Initiative are yielding positive results."


Story Source:

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


Journal Reference:

  1. Aisha Nazli, Olivia Chan, Wendy N. Dobson-Belaire, Michel Ouellet, Michel J. Tremblay, Scott D. Gray-Owen, A. Larry Arsenault, Charu Kaushic. Exposure to HIV-1 Directly Impairs Mucosal Epithelial Barrier Integrity Allowing Microbial Translocation. PLoS Pathogens, 2010; 6 (4): e1000852 DOI: 10.1371/journal.ppat.1000852

Cite This Page:

McMaster University. "New way HIV infects women discovered." ScienceDaily. ScienceDaily, 9 April 2010. <www.sciencedaily.com/releases/2010/04/100408171506.htm>.
McMaster University. (2010, April 9). New way HIV infects women discovered. ScienceDaily. Retrieved January 29, 2015 from www.sciencedaily.com/releases/2010/04/100408171506.htm
McMaster University. "New way HIV infects women discovered." ScienceDaily. www.sciencedaily.com/releases/2010/04/100408171506.htm (accessed January 29, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, January 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Malnutrition on the Rise as Violence Flares in C. Africa

Malnutrition on the Rise as Violence Flares in C. Africa

AFP (Jan. 28, 2015) Violence can flare up at any moment in Bambari with only a bridge separating Muslims and Christians. Malnutrition is on the rise and lack of water means simple cooking fires threaten to destroy makeshift camps where people are living. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Poultry Culled in Taiwan to Thwart Bird Flu

Poultry Culled in Taiwan to Thwart Bird Flu

Reuters - News Video Online (Jan. 28, 2015) Taiwan culls over a million poultry in efforts to halt various strains of avian flu. Julie Noce reports. Video provided by Reuters
Powered by NewsLook.com
Media Criticizing Parents For Not Vaccinating Children

Media Criticizing Parents For Not Vaccinating Children

Newsy (Jan. 28, 2015) As the Disneyland measles outbreak continues to spread, the media says parents who choose not to vaccinate their children are part of the cause. Video provided by Newsy
Powered by NewsLook.com
Shark Bite Victim Making Amazing Recovery

Shark Bite Victim Making Amazing Recovery

AP (Jan. 27, 2015) A Texas woman who lost more than five pounds of flesh to a shark in the Bahamas earlier this month could be released from a Florida hospital soon. Experts believe she was bitten by a bull shark while snorkeling. (Jan. 27) 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:

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