AIDS at 25

The story of women of the Pumwani settlement in Nairobi has been heard around the world. In 1984, while researchers were carrying out a study of STDs in Pumwani prostitutes, they decided to check on the prevalence HIV within the population. Because no cases of AIDS had been described in Nairobi yet, they were surprised to find that two-thirds of the population had been infected with HIV. But there were more surprises to come.

About 5 percent of the women, many of whom saw 10 or more clients a day, appeared to be resistant to HIV. It was an unprecedented finding and unfathomable considering the number of times in a year each sex worker was exposed to the virus.

Decades later, many of these women, who have become known as the Pumwani Sex Worker Cohort, remain resistant to HIV infection. Researchers, including the University of Manitoba's Frank Plummer, have identified several factors that appear to offer resistance to HIV infection, including a variety of gene signatures and the presence of higher levels of antibodies, cells and proteins within the genital tract.

The newest one on the list is trappin-2. For his PhD thesis Shehzad Iqbal used a proteomics approach to track down this novel secreted protein that may offer resistance to HIV. Although the work is preliminary, Iqbal has shown that women who are HIV resistant have higher levels of trappin-2, and that cell-based experiments show that physiological levels of trappin-2 can quelch HIV's ability to infect T-cells.

It's fascinating work, because trappin-2--should it continue to show promise following future experiments--could be incorporated in the a microbicide that women could use to protect themselves from HIV.

Amazing what our bodies can make, isn't it?