Study identifies proteins that help provide immunity against HIV among commercial sex workers in Kenya

In a study published Wednesday in the Journal of Proteome Research, researchers from the University of Manitoba, along with participants from Canada's National Microbiology Laboratory and the University of Nairobi, indentified more than 15 proteins in a group of Kenyan commercial sex workers thought to have a natural immunity to HIV, the Winnipeg Free Press reports (Tremain, Winnipeg Free Press, 9/4).

The study of 3,000 sex workers found this apparent natural immunity among 140 women in the study. Many were completely immune while others were "late converters" with high initial resistance, according to Toronto's Globe and Mail (Campbell, Globe and Mail, 9/4).

The Free Press reports that researchers found eight proteins to be much more common in a group of women apparently resistant to HIV. The proteins are known to have anti-viral properties, which may prevent HIV from multiplying, or anti-inflammatory abilities that help prevent transmission of the virus. The researchers also found about seven other proteins were diminished in HIV-resistant women, according to the Free Press (Winnipeg Free Press, 9/4).

Blake Ball, one of the lead researchers and a professor of microbiology at the University of Manitoba, said that the relative concentrations of the proteins appear to be one of the keys to explaining the group's ability to avoid becoming ill, adding that immunity likely requires unusual protein levels in addition to genetic predisposition and a highly adaptive immune system (Globe and Mail, 9/4). In addition, the Free Press reports that previous studies have shown that sex workers' apparent immunity to HIV increases the longer they are involved in sex work (Winnipeg Free Press, 9/4).

According to the Globe and Mail, the study has "considerable implications" for future research on new treatments or HIV/AIDS vaccines. Ball said researchers next should determine how and why the women's protein levels provide them with immunity and find a way to replicate the effect in others. Although Ball said the study was relatively small-scale, he said that "we're excited by this result," which "may eventually lead researchers toward a vaccine" (Globe and Mail, 9/4). Ball also added that studies by other researchers on HIV resistance among injection drug users, sex workers and couples in which one partner is HIV-positive and the other is not could provide more insight to the results of his team's study. "That's also one of the important next steps -- to see if other people who study similar groups to us can replicate our findings," Ball said (Winnipeg Free Press, 9/4).

The study is available online (.pdf).