Fig 3
β2-microglobulin (β2M) is essential for the CV-A9 infection. a The siRNA-transfected SW480 cells were cultured for 48 h and then infected with CV-A9. The infection was followed for 6 h and visualized by CV-A9-specific antibodies. The ratio of the AF 488 signal to the Hoechst (nuclei) signal was considered as the measure of efficiency of the infection. The experiment was repeated five times with mean values calculated. The error bars indicate standard deviation and the cut-off values were calculated as positive control mean ± 2 × SD. Positive control includes non-transfected, mock-transfected and scramble-transfected cells. b The cell viability was checked by staining the cells with Hoechst and Sytox Orange. The cells treated with 10 mM methyl-β-cyclodextrin (MBC) were used as “cell death” cytotoxicity controls. c SW480 and A549 cells were incubated in the presence of a function blocking β2M antibody. The infection % was calculated as a ratio of the virus signal to the Hoechst signal. The cells infected with CV-A9 in the absence of the antibody were used as positive infection controls (100 % infection). Error bars indicate the standard deviation from three independent experiments with 4–6 parallel samples and the significance reduction in infectivity is indicated with an asterisk. (P = 5.6 × 10−5 in SW480 cells and P = 2.1 × 10−5 in A549 cells)