In macrophages, HIV-1 assembles into an intracellular plasma membrane domain containing the tetraspanins CD81, CD9, and CD53.

ABSTRACT: In macrophages, HIV-1 has been shown to bud into intracellular structures that contain the late endosome marker CD63. We show that these organelles are not endosomes, but an internally sequestered plasma membrane domain. Using immunofluorescence microscopy and immunoelectron microscopy, we find that HIV-1 buds into a compartment that contains the tetraspanins CD81, CD9, and CD53. On uninfected macrophages, these proteins are seen at the cell surface and in intracellular vacuole-like structures with a complex content of vesicles and interconnected membranes that lack endosome markers, including CD63. Significantly, these structures are accessible to small tracers (horseradish peroxidase or ruthenium red) applied to cells at 4 degrees C, indicating that they are connected to the cell surface

SUBMITTER: Deneka M 

PROVIDER: S-EPMC2064140 | biostudies-literature | 2007 Apr

REPOSITORIES: biostudies-literature