Fig. 1

(A) Effect of gp120 on tubular cell apoptosis and proliferation (Representative micrographs). Equal numbers of HK-2 cells were incubated in media containing either buffer (control) or gp120 (100 ng/ml) for 16 hr. At the end of the incubation period, cells were stained with H-33342 and propidium iodide. Representative micrographs are shown (original magnification 400×). (a) Control HK-2 cells show stained nuclei. Arrow indicates an apoptotic cell with bright fluorescence and condensed nuclei. (b) HK-2 cells treated with gp120 show many apoptotic cells with bright fluorescence with condensed or fragmented nuclei (arrows). Arrowhead indicates a necrosed cell (stained pink). Equal numbers of HK-2 cells were incubated in media containing either buffer (control) or gp120 (10 ng/ml) for 16 hr. Subsequently, cells were assayed for apoptosis by TUNEL method (original magnification 200×). (c) Control HK-2 cells. (d) HK-2 cells treated with gp120. Arrows indicate apoptotic cells with darkly stained nuclei. Equal numbers of growth arrested HK-2 cells were incubated in media containing either buffer (control) or gp120 (0.01 ng/ml). Subsequently, cells were labeled for PCNA (original magnification 100×). (e) Control HK-2 cells. (f) HK-2 cells treated with gp120. PCNA-labeled nuclei show dark staining (arrows). (B) Immunostaining for tubular cell CD4 receptors in renal cortical tissue section. Formalin-fixed and paraffin-embedded human renal cortical sections were immunostained for CD4 receptors using the ABC method. (a) Negative control. An arrow indicates a glomerulus. (b) Renal tubular cells showing brown staining for CD4 receptors; glomeruli indicated by arrows (original magnification 200×). (c) Tubules indicated by asterix in (b), were further visualized under oil immersion (original magnification 1000×).