Reduction of CD4 ⁺ T cells in vivo does not affect virus load in macaque elite controllers

A small percentage of human immunodeficiency virus (HIV)- and simian immunodeficiency virus (SIV)-infected individuals spontaneously control virus replication. The majority of these elite controllers mount high-frequency virus-specific CD4 ⁺ T cell responses. To evaluate the role these responses might play in viral control, we depleted two elite controller macaques of CD4 ⁺ cells. SIV-specific CD4 ⁺ T cell responses did not return to baseline levels until 8 weeks postdepletion. Viral loads remained stable throughout the experiment, suggesting that SIV-specific CD4 ⁺ T cell responses may not play a direct role in controlling chronic viral replication in these elite controllers.