FIG. 4.

Induction of CD25⁺ FoxP3⁺ CD8⁺ T cells during SIVmac251 infection of cynomolgus macaques is correlated with plasma viral load. CD8⁺ CD25⁺ FoxP3+ T cells (A), CD8⁺ central memory T cells (B), and proportion of CD8⁺ T cells that were CD25⁺ (C) of individual macaques are shown. (Top) Six cynomolgus macaques inoculated intravenously with 5,000 AID₅₀ (open symbols). (Middle) Six cynomolgus macaques inoculated intravenously with 50 AID₅₀ (gray symbols). (Bottom) Six cynomolgus macaques inoculated intravenously with 50 AID₅₀ and treated (AZT, 3TC, and indinavir) from 4 h postinfection to 28 days postinfection (black symbols). The light gray line without symbols indicates the median plasma viral load of the corresponding macaques (A). (D and E) Positive correlation between peak number of CD8⁺ CD25⁺ FoxP3⁺ T cells and peak viral load during primary infection (P = 0.003 by Spearman correlation; r² = 0.664) (D) and between the total number of CD8⁺ CD25⁺ FoxP3⁺ T cells during primary infection (days 0 to 128), expressed as the area under the curve (AUC), and plasma viral load at 128 days postinfection (P = 0.034 by Spearman correlation; r² = 0.251) (E).