A murine cell line producing HTLV-I pseudotype virions carrying a selectable marker gene

A murine cell line, EH, expressing the gag and pol proteins of Moloney murine leukemia virus (Mo-MLV) as well as an Mo-MLV recombinant genome with a selectable marker (histidinol dehydrogenase), was transfected with a plasmid coding for the gene of the human T-cell leukemia virus type I (HTLV-I) envelope precursor (gp62), placed under the control of the human cytomegalovirus immediate early promoter. One clone, T. 14, was recovered, in which gp62 RNA and protein were detected. Supernatant from this clone transferred the HisD gene to a panel of cell lines which express receptors for HTLV-I, but was unable to pass the marker gene to cells which do not express receptors. The colony-forming units were sensitive to HTLV-I receptor interference and to specific neutralization by anti-HTLV-I serum. These data show that hybrid virions were produced in which the envelope proteins of HTLV-I had pseudotyped Mo-MLV capside particles containing a selectable recombinant viral genome.