FIG 6.

ASP is an integral protein of the plasma membrane in PMA-treated U1C8 and OM-10.1 cells. Chronically infected U1C8 (top) and OM-10.1 (bottom) cells were treated with PMA to reactivate HIV-1 expression, as described in Materials and Methods. The cells were stained with Alexa Fluor 647-labeled anti-ASP 324.6 (red) and DAPI (blue) without prior fixation and permeabilization. Finally, the cells were washed, fixed, and analyzed by confocal microscopy. The overlay of the images taken in the red (ASP) and blue (DAPI) channels shows that PMA treatment induced ASP translocation to the cell membrane. Detection of ASP on the cell surface without prior permeabilization of the plasma membrane indicates that the 324.6 mAb recognizes an ASP epitope exposed in the extracellular milieu. Bar, 2 μm. The results shown are representative of at least three independent experiments.