Reduced Frequencies and Activation of Regulatory T Cells After the Treatment of HIV-1-Infected Individuals with the CCR5 Antagonist Maraviroc Are Associated with a Reduction in Viral Loads Rather Than a Direct Effect of the Drug on Regulatory T Cells

Regulatory T cells (Tregs) play an important role in the pathogenesis of HIV-1 infection and they frequently express the chemokine receptor CCR5. We therefore investigated whether antiretroviral treatment with the CCR5 antagonist Maraviroc affected Tregs in chronically HIV-1-infected individuals. HIV-1-infected patients with high viral loads had elevated frequencies of activated Tregs in the peripheral blood compared with healthy controls. In patients successfully treated with antiretroviral drugs (undetectable viral loads), the frequency and the activation status of Tregs were comparable with healthy controls without any specific effect related to the treatment with Maraviroc. These results indicate that the control of viral replication in general rather than a direct binding of Maraviroc to CCR5-positive Tregs influences Treg responses in successfully treated chronically HIV-1-infected individuals.