Identification of a high-affinity receptor for interleukin 1 alpha and interleukin 1 beta on cultured human rheumatoid synovial cells.
J Clin Invest
; 82(2): 420-6, 1988 Aug.
Article
em En
| MEDLINE
| ID: mdl-2969918
ABSTRACT
In this report the binding of recombinant human interleukins 1 alpha and 1 beta (rIL-1 alpha and rIL-1 beta) to primary cultures of human rheumatoid synovial cells is measured and compared to the concentrations of these mediators required for stimulation of PGE2 production by these same cells. The average concentration of IL-1 alpha required for half-maximal stimulation of PGE2 was 4.6 +/- 1.5 pM (+/- SEM) (n = 6), whereas for IL-1 beta half-maximal stimulation was observed at a concentration of 1.3 +/- 0.24 pM (n = 6). Both direct and competitive binding experiments were performed. In direct binding experiments, IL-1 alpha bound with a Kd of 66 pM (n = 1), while IL-1 beta bound with a Kd of 4 pM (n = 2). In competitive binding experiments, IL-1 alpha inhibited binding of 125I-IL-1 alpha with a Ki of 33-36 pM (n = 2) and binding of 125I-IL-1 beta with a Ki of 51-63 pM (n = 2). IL-1 beta inhibited binding of 125I-IL-1 alpha with a Ki of 2-3 pM (n = 2) and binding of 125I-IL-1 beta with a Ki of 7 pM (n = 2). The binding data were best fit by a model specifying a single class of receptors with homogeneous affinity for either IL-1 alpha or IL-1 beta and with an abundance of 3,000-14,000 sites per cell. Autoradiography showed that the vast majority of the synoviocytes within the cultures possessed IL-1 receptors. Comparison of biological response curves with the binding curves indicates that the observed receptors exhibit sufficiently high affinity to mediate the response of human synoviocytes to low picomolar concentrations of IL-1 alpha and IL-1 beta.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Artrite Reumatoide
/
Membrana Sinovial
/
Receptores Imunológicos
/
Interleucina-1
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Clin Invest
Ano de publicação:
1988
Tipo de documento:
Article