Static cultures: Cells were grown in 24-well plates (Falcon) and 6-well plate experiments « Nunclon Δ». The inoculation density was 2x10 5 cells/ml and the working volume was equal to 1 ml for the 24-well plate and 3 ml when the cells were grown in 6-well plate. Cells were grown at 37°C in 5% CO 2 incubator.