Fig. 5.

TMPRSS2 and hepsin do not facilitate cathepsin-independent, Ebola virus glycoprotein-dependent host cell entry. A. Pseudotypes were generated in 293T cells expressing the indicated GPs in combination with the indicated proteases. Released pseudoparticles were normalized for equal content of p24-antigen and used to infect mock-transfected 293T cells pretreated with PBS or PBS containing 1 μM CA074Me. At 8 h post infection, medium was replaced, and luciferase activity was measured in cell lysates at 72 h post infection. B. Pseudotypes bearing the indicated GPs were normalized for comparable infectivity prior to infection of PBS or CA074Me treated 293T cells expressing the indicated proteases. C. Infectivity-normalized SARS-S pseudotypes were used to infect PBS or MDL 28170 treated 293T-ACE2 target cells expressing TMPRSS2 or no protease. The results of representative experiments performed in triplicates are shown in A–C; error bars indicate SD. Similar results were obtained in at least two separate experiments. For testing of statistical significance, a two-tailed student's t-test was employed.