Targeted infection of a retrovirus bearing a CD4-Env chimera into human cells expressing human immunodeficiency virus type 1

We constructed a hybrid Moloney murine leukaemia virus (MoMLV) bearing both a chimeric CD4 and the wild-type MoMLV envelope protein (Env) on its surface. The chimeric molecule, consisting of a surface domain of CD4 and the C-terminal two-thirds of MLV Env, was expressed on the cell surface. When expressed in MoMLV-infected cells, the CD4-Env chimera was incorporated into the virion as efficiently as the wild-type MoMLV Env. The hybrid MoMLV could infect human HeLa cells (although not with high efficiency) only if the cells were expressing human immunodeficiency virus type 1 genome. This method of ligand incorporation into a virion may lead to a development of a cell-specific retroviral vector for targeting gene therapy.

^* Author for correspondence. Present address: Laboratory of Molecular Microbiology, Building 4, Room 337, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-0460, USA. Fax +1 301 402 0226. e-mail tmatano@lightning.niaid.nih.gov