"Immune" Nairobi women also have "killer" T-cells

Further evidence that so-called "killer T-cells" could be the key to an HIV-vaccine has come from "immune" sex-workers in Nairobi, Kenya. Earlier this year, British researcher Sarah Rowland-Jones discovered a group of sex-workers in Gambia, West Africa, who seemed to be immune to HIV-infection. Study of six of the women's blood revealed that five had the T-cells, which seek out and destroy infected cells. T-cells are produced as part of the immune-system's response to infection. A second group of 30 "immune" sex-workers had been noted by social scientists in Nairobi. In April 1995, Rowland-Jones studied six of these women and again found that five had the T-cells. However, because the six Kenyan women were all of the same genetic group, the results are far from conclusive. One explanation for the women's resistance in Gambia is that they were first infected with HIV-2--a weaker strain of HIV prevalent in West Africa and India. In Nairobi, the women may have first been exposed to a defective HIV-1 virus, or their immunity may be the result of a rare genetic make-up. Rowland-Jones will return to Gambia at the end of this year to study a larger cross-section of sex-workers.