Further clues to AIDS progression

The human immunodeficiency virus can avoid the control of the immune system in most infected individuals but the mechanism involved is not completely understood. In October Nature Immunology, Stephen Migueles and colleagues at the National Institutes of Health, Bethesda, US, show that HIV-specific CD8⁺ T-cell proliferation is coupled to perforin expression and is maintained in patients who do not progress to AIDS (Nature Immunology, DOI:10.1038/ni845 October 7, 2002).

Migueles et al. examined the CD8⁺ T-cell response to HIV-infected CD4⁺ T cells in rare patients with immunological control of HIV. They observed that although high frequencies of HIV-specific CD8⁺ T cells were present in both patients who did not progress to AIDS and those who did, only those of the nonprogressors maintained a high proliferative capacity. In addition, they showed that this proliferation was coupled to increases in perforin expression.

"Given that most...