CD4/CD8 ratios in different organs.

CD4/CD8 ratio for the different organs (A) and for the sum of all organs investigated (C) was determined by flow cytometry. Infection-induced changes of the CD4/CD8 ratio relative to the mean of uninfected macaques are shown in panel B for the different organs and in panel D for the sum of all organs. Bars represent uninfected (white bars) and SIV-infected macaques with (dark gray bars) or without (light gray bars) signs of AIDS. In thymus, only CD3^high-expressing, CD4, CD8 single-positive, mature thymocytes were included. *Significantly different compared with uninfected monkeys (P ≤ .05). In panel B, the error bar for the liver of animals with AIDS was omitted because of the high variation in this group.