Fig. 3

IL2-GMCSF can bring cells into close proximity effectively. Such effects were as demonstrated by the cell cluster counting of several pairs of cell lines incubated with different concentrations of IL2-GMCSF or BHL-I. a Typical cell–cell contact (left) and separate cells (right) were shown by fluorescence microscopy observation after incubation of two types of cells stained with CellTracker™ Red or CellTracker™ Green respectively; b tumor cell lines including A1.1, B16F10, B16-GMCSF and RAW264.7 were incubated with DC2.4 cells (upper panel) or splenocytes (middle panel) in the presence different concentrations of IL2-GMCSF. Results of cell binding between DC2.4 cells and splenocytes (lower panel, left) and among splenocytes (lower panel, middle) were also shown. GM-CSF and IL-2 were used in the competition experiments to demonstrate the specific combination of IL2-GMCSF with cells (lower panel, right). The representative result of three repeat experiments with similar results was shown. *P < 0.05 compared with the control without IL2-GMCSF