Functional T cell reconstitution and human immunodeficiency virus-1-specific cell-mediated immunity during highly active antiretroviral therapy

Lymphoproliferative responses (LPRs) to recall antigens (Ags) and human immunodeficiency virus type 1 (HIV-1) Gag and frequencies of circulating HIV-I-specific cytotoxic T lymphocyte precursors (CTLps) were measured in 12 patients undergoing highly active antiretroviral therapy (HAART) after long-standing HIV-1 infection. LPRs to at least 1 recall Ag became detectable or increased in all patients during HAART. No significant LPRs to Gag-p24 were observed, whereas 4 of 8 patients tested presented with Gag-p17-specific LPRs, HIV-1-specific CTLp frequencies became measurable or increased early during therapy in 6 of 10 patients tested and were maintained or decreased thereafter. Increasing HIV-l-specific CTLp frequencies were seen only in association with partial HAART failure in 1 patient. In conclusion, restoration of CD4(+) T lymphocyte responsiveness to recall Ags is achieved during HAART. The data provide evidence for limited HIV-1-specific CDC memory T cells during advanced HIV-1 infection and suggest that both CD4(+) and CD8(+) HIV-1-specific T cells are poorly stimulated when viral load is suppressed.