Figure 5

Cell adhesion by CD4⁺ and CD4/gpi⁺ particles generated in different cell types. Vector particles without CD4 or with CD4⁺ or CD4/gpi⁺ were generated in three different producer cell lines by DNA co-transfections of HDPack1 with CD4 or CD4/gpi encoding plasmids. Equal amounts of p24 vector particles (10 ng) were added to the same number of Env⁺ or Env^- target cells (HeLa, COS-7, NIH 3T3 and CHO). Except for Env⁺ CHO-WT and Env^- CHO-EE cells, the other Env⁺ target cells were generated by high multiplicity infections with a vaccinia virus recombinant expressing either HIV-1 Env (+) or with T7 RNA polymerase (-) as a control. The amounts of adsorbed vector were normalized for each vector/target cell combination to the amount of HIV(CD4) vector adsorbed to Env⁺ target cells (= 100).