Analysis of interleukin 5 receptors on murine eosinophils: a comparison with receptors on B13 cells.
The interleukin 5 receptor (IL-5R) on murine eosinophils and a mouse B cell line (B13) was investigated using iodinated murine IL-5 produced in the baculovirus system. Electrophoretic analysis of this recombinant protein identified a range of bands Mr 26,000 to 32,000 resulting from differential glycosylation. The specific activity and binding kinetics of the iodinated IL-5 (125I-IL-5) were essentially identical to unlabeled material. Both high-affinity (Kd approximately 50 pM) and low-affinity (Kd approximately 1 nM) receptor populations were identified on murine eosinophils. Approximately 50 high-affinity receptors and 10,000 low-affinity receptors were present. This was compared with approximately 2,000 high-affinity (Kd approximately 80 pM) and about 8,000 low-affinity (Kd approximately 3 nM) sites on B13 cells. An antibody that inhibits IL-5 binding to, and proliferation of, B13 cells (R52.120) was also shown to inhibit eosinophil proliferation, suggesting that eosinophils and B cells bear the equivalent IL-5 binding proteins.
Barry
S C
SC
National Institute for Medical Research, London, England.
McKenzie
A N
AN
Strath
M
M
Sanderson
C J
CJ
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D002460:Cell Line; D003001:Cloning, Molecular; D004804:Eosinophils / Q000276:immunology*; D015848:Interleukin-5 / Q000378:metabolism*; D007700:Kinetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D011971:Receptors, Immunologic / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D018123:Receptors, Interleukin; D053649:Receptors, Interleukin-5
D015848:Interleukin-5; D011971:Receptors, Immunologic; D018123:Receptors, Interleukin; D053649:Receptors, Interleukin-5