FIGURE 4.

Heparinases, surfen, heparin, and chemically modified non-anticoagulant heparins block SV2-S pseudotyped virus infection of 293T-ACE2 cells. The 293T-ACE2 cells were infected with SV2-S pseudotyped virus expressing luciferase after the cells were treated with HSase (5 mU/ml) (A) or in the presence of surfen (20 μM) (B), heparin (HP, C), HS or chemically-modified heparins at 2- and 20 μM (D,E). The luciferase activity was measured 48 h after the virus infection. VSV pseudotyped virus was used as a control to make sure each well has comparable cell numbers (data are not shown). The experiments were repeated at least 3 times and an unpaired t-test was performed for the two-group comparison. Data are presented as mean ± SD. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. RLU, relative light unit.