RETROVIRUS PACKAGING CELLS EXPRESSING THE MUS DUNNI ENDOGENOUS VIRUS ENVELOPE FACILITATE TRANSDUCTION OF CHO AND PRIMARY HEMATOPOIETIC-CELLS

Mus dunni endogenous virus (MDEV) infects a wide variety of cell types from many different species. To take advantage of this broad host ran ge, we have constructed packaging cells (PD223) that produce virions b earing the MDEV envelope. PD223 cells are able to package Moloney muri ne leukemia virus-based vectors at a titer of 4 x 10(5) infectious uni ts per mi in the absence of contaminating replication-competent retrov irus. Vectors packaged by PD223 cells are able to transduce CHO cells, which are resistant to transduction by many retroviruses, at greater than or equal to 25-fold higher efficiency than vectors having other p seudotypes. A vector packaged by PD223 was found to be among the most efficient for transducing primary baboon and human CD34(+) cells.