Fig. 5.

Development of HA-pseudotyped lentiviral vectors. (A) Gene transfer mediated by lentiviral vectors pseudotyped with H1(1918), H5(Kan-1), or other HAs containing the H5 protease cleavage site was measured with a luciferase reporter assay. (B) Neutralization by antisera from mice immunized with the indicated HA plasmid expression vectors or no insert (control) plasmid DNA vectors was measured with the luciferase assay with the HA-pseudotyped lentiviral vectors. Reduction of gene transfer in the presence of immune sera was observed in a dose-dependent fashion (data not shown).