tac antigens were purified from surface 125i-labeled cells expressing high levels of high-affinity il-2 receptors , but low levels of the low-affinity receptor class , and this preparation was compared with another pool of tac antigens obtained from cells expressing the normal 10- to 20-fold excess of low-affinity il-2 binding sites over high-affinity il-2 receptors .
C0699040
surface
C0007634
cells