Expression cloning of a human IL-12 receptor component. A new member of the cytokine receptor superfamily with strong homology to gp130.
J Immunol
; 153(1): 128-36, 1994 Jul 01.
Article
en En
| MEDLINE
| ID: mdl-7911493
ABSTRACT
A cDNA encoding a human IL-12R subunit was isolated by expression cloning. This subunit is a 662 amino acid type I transmembrane protein with an extracellular domain of 516 amino acids and a cytoplasmic domain of 91 amino acids. It is a member of the hemopoietin receptor superfamily and is most closely related over its entire length to gp130 and the receptors for granulocyte-CSF (G-CSF) and leukemia-inhibitory factor. When expressed in COS cells, this IL-12R subunit binds both human and murine IL-12 with an apparent affinity of 2 to 5 nM. The transfected COS cells express both monomers and disulfide-linked dimers or oligomers of the IL-12R subunit on their surface. However, unlike the IL-6-induced dimerization of gp130, the oligomerization of the IL-12R subunit is not dependent on binding of IL-12. Only the IL-12R subunit dimers/oligomers but not the monomers bind IL-12 with an affinity of 2 to 5 nM. A polyclonal antiserum raised against this receptor subunit specifically inhibits IL-12-induced proliferation of PHA-activated PBMC. The data are consistent with the hypotheses that 1) a dimer/oligomer of the cloned IL-12R subunit (IL-12R-beta) represents the low affinity IL-12 binding site identified on human lymphoblasts, 2) the cloned receptor subunit is involved in IL-12 signal transduction, and 3) an additional, as of yet unidentified subunit is required to generate a high affinity IL-12R complex.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Antígenos CD
/
Interleucinas
/
Receptores de Interleucina
/
Receptores de Citocinas
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
J Immunol
Año:
1994
Tipo del documento:
Article