Tat_28-35SL8-specific CD8⁺ T lymphocytes are more effective than Gag_181-189CM9-specific CD8⁺ T lymphocytes at suppressing simian immunodeficiency virus replication in a functional in vitro assay

Epitope-specific CD8⁺ T lymphocytes may play an important role in controlling human immunodeficiency virus (HIV)/simian immunodeficiency virus replication. Unfortunately, standard cellular assays do not measure the antiviral efficacy (the ability to suppress virus replication) of CD8 ⁺ T lymphocytes. Certain epitope-specific CD8⁺ T lymphocytes may be better than others at suppressing viral replication. We compared the antiviral efficacy of two immunodominant CD8⁺ T lymphocyte responses-Tat_28-35SL8 and Gag_181-189CM9-by using a functional in vitro assay. Viral suppression by Tat-specific CD8 ⁺ T lymphocytes was consistently greater than that of Gag-specific CD8⁺ T lymphocytes. Such differences in antigen-specific CD8 ⁺-T-Iymphocyte efficacy may be important for selecting CD8 ⁺ T lymphocyte epitopes for inclusion in future HIV vaccines.