Scientists are working on two fronts toward a cure for AIDS: 1) neutralizing HIV in the human body so that regular medication is unnecessary, and 2) eradicating all traces of HIV in the body.
Human immune-system stem cells are transplanted into pups bred from these mice when they are two days old, and over the next few months, those cells mature and diversify into a working immune system. Then the mice are infected with HIV, which attacks the immune cells. But before transplanting the original human cells, the researchers introduce an enzyme that interferes with the gene for a protein the virus needs to stage the attack. This modification makes a small percentage of the mature immune cells highly resistant to HIV, and because the virus kills the cells it can infect, the modified cells are the only ones that survive over time. Thus, the HIV soon runs out of targets. If this strategy works, the virus will quickly become harmless and the mice will effectively be cured.