Figure 3. Two amino acid substitutions in the 130-loop of receptor binding domain of H5Anh are sufficient to induce H5Anh-pp production.

HEK293T cells were transfected with lentiviral gag/pol with luciferase reporter gene and a plasmid coding for either wild-type or H5Anh mutants described in Table 1. NAvb was added 16 hr post transfection. (A) Cell lysates at 48 hr post transfection were analyzed for HA protein expression using anti-FLAG antibody. GAPDH antibody was used as the loading control. (B) Supernatant containing H5pp was harvested and used to transduce MDCK cells. Luciferase activity was measured at 72 hr post transduction and results are shown as means ± SD (n = 3 independent experiments); *p<0.01 compared with H5Anh by the unpaired Student's t-test.