Figure 1. Expression of transgenes transferred by HSV amplicon-mediated gene transfer. (A) Peak amount of either GM-CSF (white/gray bars) or RANTES (black bars) secreted into the growth medium by cells infected with HSV amplicons (multiplicity of infection = 1) carrying the genes for GM-CSF, RANTES, or lacZ. GM-CSF or RANTES expression peaked at day 2 after infection. (B) Flow cytometry results using an FITC-conjugated anti-B7-1 antibody after infection with HSVB7.1. The upper graph represents noninfected cells; the bottom graph represents cells exposed 2 days before HSV-B7.1 (multiplicity of infection = 1). Fifty-nine percent of cells exposed to the amplicon were FITC positive, while only cells not exposed were FITC negative.