Figure 4

The role of integrins in infection of low CAR cells. (A) Cells were preincubated with media alone, increasing concentrations of synthetic peptide GRGDSP, or control peptide GRGESP for 1 hr followed by the addition of Ad5, all at 4°C for 6 hrs. Samples were then washed and fixed and virus bound was detected using an ELISA binding assay with an antibody to Ad5 as described in materials and methods. Data shown is the average of at least three independent experiments and error bars represent standard deviation. * indicates statistical significance, p ≤ 0.05. (B) Surface integrin levels were determined using flow cytometry. Cells were stained with LM609 (integrin αvβ3), P1F6 (integrin αvβ5), JB1A (integrin β1), or secondary only control, goat anti-mouse Alexa 488. The secondary only population was set to approximately 1% positive and used as the negative population for each cell line. The percentage of cells which are positive for each integrin as well as the MFI is quantified and displayed in Table 2. Data shown is representative of at least two independent experiments. (C) Cells were preincubated with media alone or the blocking antibodies LM609, P1F6, OR JB1A for 1 hr followed by the addition of Ad5, all at 4°C. Virus bound was determined as described in (A). Data shown is the average of at least three independent experiments and error bars represent standard deviation. * indicates statistical significance, p ≤ 0.05; ** indicates statistical significance, p ≤ 0.01.