Viral loads and peripheral CD4+ T cell counts. Viral loads and CD4 counts were measured every 2 to 3 weeks throughout the experiment. (A) Viral RNA in plasma was quantified by a bDNA signal amplification assay and expressed as viral RNA copies per ml plasma. ART treatment controlled the viral loads in all three animals. (B) Peripheral CD4+ T cell counts increased after the initiation of ART. Macaque blood samples were stained for CD3, CD4, and CD8 and the number of CD3+, CD4+ T lymphocytes were determined by flow cytometry and peripheral white blood cell counts. CD4+ T cell counts are expressed as CD4+ T cells per μl blood.