Induction of an interleukin-1 receptor (IL-1R) on monocytic cells. Evidence that the receptor is not encoded by a T cell-type IL-1R mRNA.
Primary human monocytes and the human monocytic cell line THP-1 were induced to express receptors for interleukin-1 alpha (IL-1 alpha) and IL-1 beta. Treatment of primary monocytes with dexamethasone resulted in a 10-fold increase in receptor number over untreated cells, to approximately 2,000 receptors/cell. Treatment of THP-1 cells with phorbol ester followed by prostaglandin E2 and dexamethasone resulted in the expression of approximately 30,000 receptors/cell. Competitive binding assays on THP-1 cells showed that both IL-1 alpha and IL-1 beta bind to the same receptor. The monocyte IL-1R is significantly smaller (63 kDa) than the T cell IL-1R (80 kDa) and is immunologically distinct. However, induction of monocytes and monocytic cell lines leads to the appearance of an abundant mRNA of approximately 5,000 bases which hybridizes to a cDNA probe from the T cell-type IL-1R. Sequence data obtained from a cDNA clone of this mRNA indicate that the message is identical to the T cell IL-1R mRNA throughout the coding region. A smaller mRNA, also homologous to the T cell IL-1R mRNA, accumulated in induced THP-1 cells and has a shorter 3'-untranslated region than the larger. Data are presented which suggest that neither form of this message encodes the 63-kDa IL-1R, but rather that this protein is the product of a separate nonhomologous mRNA.
Spriggs
M K
MK
Immunex Research and Development Corporation, Seattle, Washington 98101.
Lioubin
P J
PJ
Slack
J
J
Dower
S K
SK
Jonas
U
U
Cosman
D
D
Sims
J E
JE
Bauer
J
J
D002460:Cell Line; D003907:Dexamethasone / Q000494:pharmacology; D015232:Dinoprostone / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism*; D007700:Kinetics; D009000:Monocytes / Q000187:drug effects / Q000276:immunology*; D012333:RNA, Messenger / Q000235:genetics*; D011971:Receptors, Immunologic / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D017472:Receptors, Interleukin-1; D011994:Recombinant Proteins / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D007375:Interleukin-1; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1; D011994:Recombinant Proteins; D003907:Dexamethasone; D015232:Dinoprostone; D013755:Tetradecanoylphorbol Acetate