Interleukin-1 receptor antagonist binds to the type II interleukin-1 receptor on B cells and neutrophils.
We have examined the binding of human and rodent interleukin-1 receptor antagonist (IL-1ra) to the type II IL-1 receptor on the human B cell line, Raji, on the mouse pre-B cell line, 70Z/3, and on human polymorphonuclear leukocytes (PMNs). Human IL-1ra binds to the receptors on the human B cells with an affinity (KD = 15 +/- 3 nM) equal to that of IL-1 alpha and only 15-fold lower than that of IL-1 beta and, likewise, binds to human PMNs with an affinity (KD = 8 +/- 4 nM) 15-fold lower than that of IL-1 beta. Mouse and rat IL-1ra bind to these two human cell types with an affinity similar to that of the human protein. Human IL-1ra binds very weakly to the type II receptor on the mouse pre-B cells with an affinity (KD = 1.4 +/- 0.2 microM) about 1500-fold lower than human IL-1 beta. Mouse and rat IL-1ra also bind to the mouse pre-B cells with low affinity. The weak binding of the three IL-1ra proteins to these mouse cells appears to be more a consequence of the cell type rather than species specificity. There may be a population of cells for which the actions of IL-1 cannot be effectively opposed by IL-1ra, although this group does not include mature B cells and PMNs.
Dripps
D J
DJ
Synergen, Inc., Boulder, Colorado 80301.
Verderber
E
E
Ng
R K
RK
Thompson
R C
RC
Eisenberg
S P
SP
D000345:Affinity Labels; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D001667:Binding, Competitive; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism*; D051379:Mice; D009504:Neutrophils / Q000378:metabolism*; D051381:Rats; D011971:Receptors, Immunologic / Q000037:antagonists & inhibitors*; D017472:Receptors, Interleukin-1; D013045:Species Specificity
D000345:Affinity Labels; D003432:Cross-Linking Reagents; D007375:Interleukin-1; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1