HSV-1 derived amplicons expressing cytoplasmic beta-galactosidase (pA-SF1), or plasma membrane targeted TIMP-Thy1 (pA-TT1), were used to transduce glial cells in vitro. By monitoring the expression of reporter genes from both amplicons and helper virus, we determined that many cells were infected by both particles. In glial cells infected only by pA-SF1 beta-galactosidase immunoreactivity was restricted to the cytoplasm; co-infection with helper HSV-1 (wild type), resulted in additional nuclear beta-galactosidase immunoreactivity. Co-infection of cells with amplicon pA-TT1 and helper virus did not affect the plasma membrane localization of TIMP/Thy1. Thus, co-infection with wild type helper virus altered the localization of an amplicon encoded cytoplasmic, but not plasma membrane protein.