HIV with Defective Nef Gene Is Harmless
Recently, five people in Australia who are HIV positive but have not developed AIDS in 14 years were found to have all received a blood transfusion from the same HIV positive person, who also has not developed AIDS. This led scientists to believe that the strain of virus transmitted to these people has some sort of genetic defect which prevented it from effectively disabling the human immune system. In subsequent research, a defect was found in one of the nine genes present in the AIDS virus. This gene is called nef, previously named to stand for "negative factor," and seemed to be missing some pieces of genetic material in the six Australians. Viruses with the defective gene may not be able to reproduce as much and thus be kept in check by the immune system.

This finding has exciting implication for developing a vaccine against AIDS. Before this, scientists have been unsuccessful in trying to produce a strain of HIV that is harmless but can ilicit an immune response. The Australian strain with the defective nef gene has the potential to be used in a vaccine that would arm the immune system against this and other strains of HIV.

Another application of this discovery is its use in developing drugs that inhibit gene products that increase the virus's replication. It seems that the protein produced from the nef gene is one of these critical gene products, because viruses with defective forms of nef do not reproduce much, as in the cases of the six Australians. Research is currently underway to develop a drug that targets the nef protein.

Source: "AIDS Virus's Genetic Armor May Have a Vulnerable Spot" by Lawrence K. Altman, New York Times, November 10, 1995