Fig. 4.

At the time of death, two SIV-infected monkeys had lost virtually all of their CD4⁺ memory T cells from the blood and lymph nodes. EDTA-treated blood samples or mesenteric lymph node suspensions, collected before death from macaques RHCK2K and RHCK2F, were gated on CD4⁺ T cells and stained for the indicated surface markers that distinguish naïve and memory cells. The percentages are indicated for each CD4⁺ T cell subset.