Figure 7.  IL15 promotes the early acquisition of NK1.1 and Qa1 receptors by developing NK cells in a similar manner to IL2

1 day in IL2 or IL15

3 days in IL2 or IL15

2 days in IL4 + PMA

Qa1R

NK1.1

Immature NK cells were obtained from E14 thymus and cultured initially for 2 days in IL4 + PMA.  They were then

washed, cultured for 1 or 3 days in medium containing 20nM IL2 or IL15, then double stained with Qa1 tetramers and

mAb to NK1.1

Conclusions

1.  Within 24 hr of placing NK cell progenitors in medium containing IL2 or IL15 a substantial proportion have acquired NK1.1.

2.  Within 72hr, most cells have acquired NK1.1 and the proportion of cells with Qa1 receptors has increased markedly, the

vast majority of the latter residing within the NK1.1 positive population.

3.  The pattern and kinetics of acquisition of NK1.1 and Qa1 receptors are essential identical regardless of whether NK cell

differentiation is driven by IL2 or IL15.