FIG. 2.

(A) Secreted GLA-αHer2-GFP fusion proteins bind to Her2-positive SK-BR-3 cells in vitro. Supernatant from 293 cells stably transfected to express various GLA fusion proteins or controls was incubated with 1 × 10⁶ MDA-MB-435 or SK-BR-3 cells. For Her2 expression analysis, cells were incubated with biotinylated Herceptin followed by streptavidin Alexa Fluor 488 incubation. After 1 hr of incubation on ice, cells were washed and analyzed by fluorescence-activated cell sorting (FACS) for green fluorescence. Incubation of Ad-Red virus with GLA-αHer2-GFP protein before infection increased the transduction of Her2-positive cells. Ad-Red viral particles (1 × 10⁷) were incubated with supernatant from cells expressing GLA-αHer2-GFP or control protein for 1 hr and then applied to cells for 30 min at 37°C. Cells were then washed and plated overnight. After 24 hr, cells were trypsinized and analyzed by FACS. (B) Percent dsRed positive. (C) Mean fluorescence index (MFI). ***p < 0.001.