Specific interaction of CD4-bearing liposomes with HIV-infected cells.

The CD4 molecule was reconstituted into the bilayers of large liposomes. Fluorescence microscopy and electron microscopy showed that these liposomes interact with HIV-infected H9-HT cells, delivering their contents to the cell interior. Liposomes bearing CD4 did not interact in this way with noninfected H9-HT cells nor did liposomes without CD4 interact significantly with HIV-infected cells. From electron micrographs, it appeared that HIV binds to liposomes bearing CD4; no attachment of virions to liposomes without CD4 was observed.