Over the years, the AIDS virus has increasingly adapted itself to humans. This is shown by the research of Youssef Gali at the Institute of Tropical Medicine (ITM). Gali also developed a model system imitating the vagina and cervix, and used it to assess the safety of protective vaginal gels. His research yielded a deeper insight in the interactions between the HIV virus and human cells, and now results in a doctorate at the Institute of Tropical Medicine and the Universiteit Antwerpen.
Science knows the virus for thirty years now, and before that it already circulated several decades among humans, but still we only partially understand what it does to a human body – and what human cells do with the virus. Most infections happen in the vagina, but we know to little about the processes in the tissues and cells of a vagina, and still less about what happens when an AIDS virus travels trough those tissues, to purposively develop drugs that block the transmission of the virus.
Fort some time now, tests are running with vaginal gels that should block, or at least hinder, transmission. The results are slowly getting better, but they still are far from good. Nevertheless, the ITM researchers who work on these gels for several years now, believe an infection-suppressing vaginal gel to be within reach in a few more years.
To filter out unsuccessful products before they are tested on humans, Youssef Gali employed two model systems. In one he used living tissue from vagina and cervix, donated by women whose womb was removed. In the other he used a layer of cultivated human vaginal cells, covering a layer of blood cells. The first is very close to the human situation, the latter is easier to work with. With these models he discovered how exactly the virus proceeds through the vagina.
The models also showed which ingredients in vaginal gels are harmful to vaginal tissues, and which candidate active substances have the best chance to prevent in real circumstances the virus from entering through the vagina.
Gali also compared virus isolates from halfway the eighties with samples from the late nineties, both from an Amsterdam cohort of volunteers. He could prove that within fifteen years the virus was ‘fitter’, i.e. more suitable to infect human cells and to survive in them. A beautiful, though a bit grim, example of the evolution in action.
Source: Institute of Tropical Medicine