Interleukin-1 inhibits PGE2 binding to macrophage-like P388D1 cells by a cyclic AMP-independent process.
The interaction between interleukin IL-1 alpha and PGE2 on P388D1 cells has been investigated. Preincubation of murine macrophage-like cells, P388D1, with IL-1 alpha (0-73 pM) reduced the binding of PGE2 to these cells in a concentration-dependent manner. Scatchard analysis showed that IL-1 alpha decreased the PGE2 binding by lowering both the high and low affinity receptor binding capacities (from 0.31 +/- 0.02 to 0.12 +/- 0.01 fmol/10(6) cells for the high affinity receptor binding sites and from 2.41 +/- 0.12 to 1.51 +/- 0.21 fmol/10(6) cells for the low affinity receptor binding sites). However, the dissociation constants of the receptors of the IL-1 alpha-treated cells remained unchanged. Inhibition of PGE2 binding by IL-1 alpha did not involve changes in either protein phosphorylation or intracellular cyclic AMP levels. Our data clearly show that IL-1 alpha inhibits the binding of PGE2 to monocytes/macrophages and may thereby counter the immunosuppressive actions of PGE2.
Rae
M G
MG
Division of Pharmacology, University of Aberdeen, U.K.
Rotondo
D
D
Milton
A S
AS
Dutta-Roy
A K
AK
D000818:Animals; D001665:Binding Sites; D002460:Cell Line / Q000187:drug effects; D000242:Cyclic AMP / Q000378:metabolism*; D015232:Dinoprostone / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007375:Interleukin-1 / Q000494:pharmacology*; D007700:Kinetics; D007941:Leukemia P388 / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D011982:Receptors, Prostaglandin / Q000187:drug effects
D007375:Interleukin-1; D011982:Receptors, Prostaglandin; D000242:Cyclic AMP; D015232:Dinoprostone