Researchers identify good bacteria that protects against HIV
Scientists have, for the first time, grown vaginal skin cells outside the body to improve chances of identifying the good bacteria that protect women from HIV infection and other sexually transmitted diseases.
Globally, AIDS-related illnesses are the leading cause of death among women of reproductive age.
In areas such as Western and Central Europe, Eastern Europe and Oceania, women account for a relatively low percentage of people living with HIV. However, in regions such as Sub-Saharan Africa and the Caribbean, the percentage is significantly higher.
At the end of 2012, it was estimated that 52 percent of people living with HIV and AIDS in low- and middle-income countries are women.
Every minute one young woman becomes infected with HIV, with Sub-Saharan Africa reporting that the percentage of young women aged 15-24 living with HIV is twice that of young men. Biologically, women are more likely to become infected with HIV through unprotected sex than men.
In many countries, women are less likely to be able to negotiate condom use and are more likely to be subjected to non-consensual sex. Researchers at the University of Texas Medical Branch (UTMB) at Galveston and the Oak Crest Institute of Science in Pasadena, California, set out to study the relationship between the skin cells and the good bacteria.
Researchers at the University of Texas Medical Branch have identified good bacteria that protect women against HIV.
Based on a publication released recently, a team of scientists representing multiple disciplines at UTMB and the Oak Crest Institute of Science has reported a new method for studying the relationship between the skin cells and the good bacteria.
They have revealed that growing vaginal skin cells outside the body and studying the way they interact with good and bad bacteria might enable them to better identify the good bacteria that protect women from HIV infection and other sexually transmitted infections.
The health of the human vagina depends on a mutually beneficial relationship with good bacteria that live on its surface feeding on products of vaginal skin cells.
These good bacteria, in turn, create a physical and chemical barrier to bad bacteria and viruses, including HIV.
These experts are the first to grow human vaginal skin cells in a dish in a manner that creates surfaces that support colonisation by the complex good and bad communities of bacteria collected from women during routine gynaecological exams.
The bacterial communities have never before been successfully cultured outside the human body.
The research group, led by Richard Pyles at UTMB, reports in the journal, PLOS One, that by using the model of a human vagina, they discovered that certain bacterial communities alter the way HIV infects and replicates.
He said their laboratory model will allow careful and controlled evaluation of the complex community of bacteria to ultimately identify those species that weaken the defenses against HIV.
Pyles also indicated that this model “will provide the opportunity to study the way that these mixed species bacterial communities change the activity of vaginal applicants, including over-the-counter products like douches and prescription medications and contraceptives.
“These types of studies are very difficult or even impossible to complete in women who are participating in clinical trials.”
In fact, the team's report documented the potential for their system to better evaluate current and future antimicrobial drugs in terms of how they interact with good and bad bacteria.
In their current studies, a bacterial community associated with a symptomatic condition called bacterial vaginosis substantially reduced the antiviral activity of one of the leading anti-HIV medicines.
Conversely, vaginal surfaces occupied by healthy bacteria and treated with the antiviral produced significantly less HIV than those vaginal surfaces without bacteria treated with the same antiviral.
Dr Marc Baum, the lead scientist at Oak Crest and co-author of the work has said “this model is unique as it faithfully recreates the vaginal environment ex vivo, both in terms of the host cellular physiology and the associated complex vaginal microbiomes that could not previously be cultured. I believe it will be of immense value in the study of sexually transmitted infections.”
Recently a researcher in HIV/AIDS prevention for the US Centres for Disease Control and Prevention also reveals a new vaginal gel with potential to protect women from HIV, even if it is applied several hours after sex, animal research suggests.
According to the study published on March 12 in Science Translational Medicine, lead author Walid Heneine, a researcher in HIV/AIDS prevention for the US Centres for Disease Control and Prevention says that such a gel could be extremely useful in protecting women from HIV, because it can provide protection either before or after sexual activity.
The two studies are still to be approved. Do not expect the gel to be on the market any time soon, however. Researchers are a few years away from human clinical trials, Heneine says, because they are working on improving the gel's effectiveness. And results of animal trials aren't necessarily replicated in humans.