Expression of CD83 (A and C) and HLA-DR (B and D) versus green fluorescence in uninfected cells (A and B) and cells infected with Ad5RSVGFP in the presence of liposomes (C and D). The vertical and horizontal lines distinguish CD83⁻ and HLA-DR⁻ cells (left of and below the line, respectively) from CD83⁺ and HLA-DR⁺ cells.