Scientists have invented a new approach to combating AIDS by using another virus to selectively target and eliminate cells that are infected with HIV.

The same strategy was used by two groups—a team from the United States using a defective vesicular stomatitis virus and a group from Germany using a modified rabies virus (Cell 1997;90:841-7, 849-59). This is the first time that viruses have been engineered to infect and kill another virus, and the approach may have applications beyond the treatment of AIDS.

HIV usually gains entry into T cells by binding its cell envelope protein, gp120, with the T cell surface receptors CD4 and fusin. A cell infected with HIV signals that it is infected by displaying …