Increased macrophages turnover in mesenteric lymph node from SIV-infected (AIDS) macaque. Lymph nodes were collected 24 hours after BrdU injection from uninfected and SIV-infected macaques. The percentages of BrdU⁺ monocytes in the uninfected and infected monkeys shown in this figure were 3.0% and 45.3%, respectively. Group data are shown in Table 3. Triple-label confocal microscopy was performed for CD163 (macrophage marker, blue), BrdU (red) to identify recently arrived macrophages, and TUNEL (green) to identify apoptotic macrophages. (A,B) From follicular areas and (C,D) from the cortical sinus areas in mesenteric lymph nodes from an uninfected animal (A,C) and an SIV-infected animal (B,D). Each panel is representative of 5 different fields of the follicular and the cortical sinus areas. Confocal microscopy was performed using a Leica TCS SP2 confocal microscope equipped with 3 lasers (Leica Microsystems). An oil objective 40× fluotar/NA 1.0 was used to image the slides. Scale bar, 74 μm. Magnification, × 40.