Why are women vulnerable to HIV?

TORONTO - Women are susceptible to the HIV virus that causes AIDS as it breaks the resistance of epithelial cells - the protective barrier that keeps infection out in the female reproductive tract, research says.

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

For the first time, researchers at McMaster University have discovered that the culprit could be HIV itself and what it 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,” lead researcher Charu Kaushic said.

“This is a significant step forward in defining where prevention strategies like microbicides and vaccine need to focus,” said Kaushic, associate professor at the Centre for Gene Therapeutics (CGT) and the department of pathology and molecular medicine in the Michael G. DeGroote School of Medicine.

“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,” Kaushik added.

The study shows that HIV can break down the mucosal barrier in the intestinal and female genital tract, allowing the virus to cross during intercourse, said a McMaster’s release.

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 the inside of the body, the researchers said.

The study appears in PLoS Pathogens.