Figure 4.  CTLL2 cells proliferate efficiently to low concentrations of IL2 and IL15
CTLL2 cells were cultured in serial dilutions of IL2 or IL15 for 3 days.
Conclusions
1.  CTLL2 cells proliferate strongly at low [20pM] concentrations of IL2.
2.  They also proliferate extremely well at low concentrations of IL15 demonstrating that
the IL15 preparations used have high biological potency.
3.  The reasons why CTLL2 cells respond efficiently to IL15 whereas normal T cells do
not, and why human IL15 is more active on CTLL2 cells than mouse IL15, are unknown.