Virus-specific CD4(+) T cell help and CD8(+) cytotoxic T cell (CTL) responses are critical for the maintenance of effective immunity in chronic viral infections. HIV-1 infection presents a unique situation in which HIV-1-specific T helper cell responses are characteristically impaired and virus-specific CTLs wane over time as disease progresses; a relationship exists between T cell help and CTL responses in HIV-1 infection.