Human B lymphocytes express the p75 component of the interleukin 2 receptor.
The nature of the interleukin 2 (IL-2) receptor on purified human B lymphocytes was examined. Both normal and malignant cells showed evidence of a 70-75,000 mol. wt (p75) IL-2 binding molecule as assessed by 125I-labeled IL-2 binding and receptor cross-linking. On normal, Tac-negative B lymphocytes the estimated number of p75 binding sites was 1100 per cell and the dissociation constant (Kd) was 1.7 nM. Consistent with this, cross-linking experiments demonstrated the presence of an IL-2 binding molecule of 70-75,000 mol. wt. Purified B cells from patients with hairy cell leukemia and chronic lymphocytic leukemia (CLL) also expressed the p75 IL-2 binding molecule. In the HCL samples, a small number of high-affinity IL-2 binding sites were detected (27-90) while the majority of binding sites (2100-10,800) were typical of low-affinity p55 Tac binding. IL-2 added to the purified normal and CLL B lymphocytes led to the induction of p55 Tac expression and the generation of high-affinity IL-2 receptors. This response to IL-2 was equivalent to the response observed when normal B lymphocytes were stimulated by Staphylococcus aureus Cowan I.
Begley
C G
CG
Metabolism Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
Burton
J D
JD
Tsudo
M
M
Brownstein
B H
BH
Ambrus
J L
JL
Waldmann
T A
TA
D015703:Antigens, CD / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology*; D002051:Burkitt Lymphoma / Q000276:immunology*; D002460:Cell Line; D003432:Cross-Linking Reagents / Q000494:pharmacology; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D015375:Receptors, Interleukin-2 / Q000302:isolation & purification / Q000378:metabolism*; D013388:Succinimides / Q000494:pharmacology
D015703:Antigens, CD; D003432:Cross-Linking Reagents; D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D013388:Succinimides; C019358:disuccinimidyl suberate