FIG. 2.
The inhibitory activities of SARS patients' sera and selected small molecules against the HIV-luc/SARS pseudotyped virus to enter Vero E6 cells. (a) Detection of inhibitory activities of sera of SARS patients. Note the ability of the SARS patient sera to block the infectivity of HIV-luc/SARS (SARS) versus the absence of such blocking activity in normal serum; note also the lack of neutralizing activity of the SARS sera against the pseudotyped virus bearing the G protein of VSV (VSV), which could infect the target cells at a similar level to that of HIV-luc/SARS. The serum dilution are indicated. (b) Structures and inhibitory activities of TGG and luteolin. Note the high inhibitory activity of TGG (EC50 = 2.86 μM), which is consistent with its high affinity to the SARS S2 protein, as our data demonstrated (Fig. 1c and d and Table 1). (c) Specificities of TGG and luteolin inhibitory activities. HIV-luc/VSV (VSV) pseudotyped viruses were used as a control. Note the inhibition by TGG and luteolin of the entry of HIV-luc/SARS virus but not the HIV-luc/VSV pseudotyped virus. Values are averages of triplicate determinations. The bars indicate the standard deviations.