Interleukin 2 receptors.
Interleukin 2 receptors (IL-2-R) are composed of (at least) two chains: the alpha chain (or p55 or Tac) and the beta chain (or p70 or p75). The association of both chains constitutes high affinity IL2-R complexes (Kd congruent to 10-100 pM), whereas the alpha-chain or the beta chain alone bind IL-2 with low (Kd congruent to 5-50 nM) and intermediate (Kd congruent to 1 nM) affinities, respectively. The beta chain (but not the alpha chain) mediates IL-2 internalization and signal transduction (proliferation or differentiation) to the cell, thus only high and intermediate affinity IL-2-R are functional. High affinity IL-2-R are expressed on activated normal and leukemic T and B lymphoid cells. Low affinity IL-2-R (Tac alone) are seen on stimulated T cells, B cells, and monocytes, as well as on various leukemic cells. The p70 chain alone is constitutively expressed by subsets of normal resting T and B cells, LGL and NK cells and we have recently demonstrated its presence on leukemic cells from various hemopoietic lineages. The finding of IL-2-R on non-lymphoid cells may disclose new functions for IL-2.
Unité d'Oncogénèse Appliquée, INSERM U 268, Hôpital Paul Brousse, Villejuif, France.
M
M
Allouche
Y
Y
Sahraoui
Y
Y
Augery-Bourget
M
M
Perrakis
C
C
Jasmin
V
V
Georgoulias
D001402:B-Lymphocytes / Q000378:metabolism; D001665:Binding Sites; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D007938:Leukemia / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000378:metabolism
D007376:Interleukin-2; D015375:Receptors, Interleukin-2