pDC dynamics in the peripheral lymph nodes of cynomolgus macaques after infection with SIV. (A) Representative dot plot showing CD123⁺ CD1c⁻ pDCs in a lineage (CD3, CD8, CD14, and CD20)⁻ HLA-DR⁺ gate, in lymph node cells. (B) Changes in the numbers of pDCs in sequential peripheral lymph node biopsies over time. Solid gray lines: macaques infected with 50 AID₅₀; solid black lines: macaques infected with 5000 AID₅₀. P values are given for the Wilcoxon rank test. (C) Distribution of CD123⁺ cells in lymph nodes of SIV-uninfected (left panel) and SIV-infected macaques (day 38 after exposure, right panel). Photographs are representative of 2 SIV-negative and 3 SIV-positive macaques and of the entire section observed. Serial lymph node sections (10 μm) were either double-labeled for CD123 and CD20 (top panel), or CD123 and CD3 (bottom panel), or stained with isotypic control antibodies or DAPI (Figure S1). Magnification: ×100. Inset magnification: ×200 (top left, top right, bottom left) and ×400 (bottom right).