HIV-specific CD8+ T cell proliferation is coupled to perforin expression and is maintained in nonprogressors.

It is unclear why immunological control of HIV replication is incomplete in most infected individuals. We examined here the CD8+ T cell response to HIV-infected CD4+ T cells in rare patients with immunological control of HIV. Although high frequencies of HIV-specific CD8+ T cells were present in nonprogressors and progressors, only those of nonprogressors maintained a high proliferative capacity. This proliferation was coupled to increases in perforin expression. These results indicated that nonprogressors were differentiated by increased proliferative capacity of HIV-specific CD8+ T cells linked to enhanced effector function. In addition, the relative absence of these functions in progressors may represent a mechanism by which HIV avoids immunological control.