Figure 7.

Quantitation of apoptotic cells in red pulp during SIV infection. A: Immunohistochemistry for cleaved caspase-3 was performed on spleen sections obtained from uninfected animals and during the acute, asymptomatic, and chronic phase of infection to identify apoptotic cells. Images from one animal, that are representative of nine examined, are shown. Brown staining indicates cleaved caspase-3, denoted by arrows. B: Quantification was performed using Nikon Elements software and the percentage of cells with cleaved caspase-3 immunoreactivity per μm² within the red pulp was obtained. Spleen sections were double labeled for cleaved caspase-3 and CD68 (C) or CD163 (D). Images from one animal, representative of six animals, are shown. Cleaved caspase-3 positive CD68 (C) and CD163 (D) macrophages are indicated by arrows. Statistical significance was determined by Kruskal-Wallis analysis of variance test. Data are expressed as means ± SD. ^∗P ≤ 0.05. Original magnification, ×20 (A, C, and D).