mrspoonsi sends this news from Scientific American: "The difference between HIV infection and full-blown AIDS is, in large part, the massive die-off of the immune system's CD4 T-cells. But researchers have only observed the virus killing a small portion of those cells, leading to a longstanding question: What makes the other cells disappear? New research shows that the body is killing its own cells in a little-known process. What's more, an existing, safe drug could interrupt that self-destruction, thereby offering a way to treat AIDS. The destructive process has caught scientists by surprise. 'We thought HIV infects a cell, sets up a virus production factory and then the cell dies as a consequence of being overwhelmed by virus. But there are not enough factories to explain the massive losses,' says Warner Greene, director of virology and immunology at the Gladstone Institutes, whose team published two papers today in Science and Nature describing the work. Greene estimates 95 percent of the cells that die in HIV infections are killed through pyroptosis, so the findings raise hope for a new type of treatment that could prevent HIV from progressing into AIDS. 'Inhibiting activation of the immune system is not a new concept, but this gives us a new pathway to target,' says Robert Gallo. And in fact, a drug already exists that can block pyroptosis."