A retroviral vector capable of targeted gene transfer into cells expressing HIV envelope glycoprotein

An expression vector encoding a chimeric envelope protein composed of CD4 a nd ecotropic retroviral envelope glycoprotein was constructed with the aim of accomplishing targeted gene transfer into HIV-1-infected cells. The chim eric protein was efficiently expressed and transported to the surfaces of v arious cell types and supported HIV-1 entry into human cells. A packaging c ell line producing retroviral vectors carrying chimeric envelope proteins w as then established. The vector particles produced were shown to be capable of specific gene transfer into human cells expressing HIV envelope glycopr otein. Blocking experiments confirmed that the vector particles entered the cells via an interaction between the chimeric and HIV envelope proteins. T his targeting vector may thus Be a useful tool with which to develop effect ive gene therapies against HIV infection. (C) 2000 Academic Press.