Identification of a soluble, high affinity human interleukin 4 binding protein in normal human urine.
We report the existence of a protein in normal human urine that binds, specifically and with high affinity (Kd approximately 1.9 nM) to human interleukin 4 (IL-4) and thereby prevents the binding of the cytokine to the high affinity receptor. The urinary binding protein has a molecular weight of 40 kD and 23 kD after deglycosylation. The binding protein has been purified by affinity chromatography. It inhibited IL-4-dependent (but not IL-2-dependent) T-cell proliferation. This protein may play a role in vivo in regulating the biological activities of this important immunoregulatory cytokine.
Christie
G
G
Department of Nuerosciences, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex, UK.
Dacey
I
I
Weston
B J
BJ
D015703:Antigens, CD / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology / Q000652:urine*; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006023:Glycoproteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology / Q000652:urine*; D006801:Humans; D015847:Interleukin-4 / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D008970:Molecular Weight; D018123:Receptors, Interleukin / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D019948:Receptors, Interleukin-4; D011994:Recombinant Proteins / Q000378:metabolism; D012995:Solubility; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology
D015703:Antigens, CD; D002352:Carrier Proteins; D006023:Glycoproteins; D018123:Receptors, Interleukin; D019948:Receptors, Interleukin-4; D011994:Recombinant Proteins; D015847:Interleukin-4