Figure 5. CD4⁺ T cell depletion pattern in SIVagm-infected macaques.

PBMCs were examined by polychromatic flow-cytometry for their correlated expression of cell surface CD3 vs CD4 vs CCR5 vs CD28 vs CD95 vs CXCR4 both before and 28 days after infection. Note the striking depletion of CD4⁺ memory T cells (CD95⁺), and within the memory population, the effector memory (CD28^negCD95⁺) and the CCR5-expressing subsets. Meanwhile, CXCR4-expressing cells are well maintained during acute SIVagm.sab infection in RMs. This pattern is identical to the one reported by Picker et al., for CCR5 tropic viruses [25].