Fig. 3

(A) Fluorescence microscopy visualization of Ad5-FK interaction with HEK293 cells. After treating HEK293 cells with purified FK protein, followed by incubation with FITC-conjugated anti-His tag antibody and DAPI stain, the interaction between FK and cell surface was visualized as distinct green dots surrounding HEK293 cells with blue-stained nuclei under fluorescence microscope at 40× magnification. (B) Competition of Ad5-FK with human adenovirus in binding to HEK293 cells. Following pre-incubation with different concentrations (5, 10, 20, 30, 100 ng/ml) of FK or SR proteins, cells were treated with rAd5-GFP at MOI 5. Eighteen hours later, virus infection was monitored by FACs through the expression of the reporter gfp gene. FK demonstrated the ability to reduce cell infection with the virus by up to 85% at a concentration of 100 ng/ml. In contrast, the negative control (SR) exhibited no inhibitory effect