Autor: |
Capper SJ; Life Sciences Business, Cardiff, Wales, U.K., Kalinka S, Mander TH |
Jazyk: |
angličtina |
Zdroj: |
Cytokine [Cytokine] 1990 May; Vol. 2 (3), pp. 182-9. |
DOI: |
10.1016/1043-4666(90)90014-k |
Abstrakt: |
We have developed specific radioimmunoassays for interleukin 1 alpha (IL 1 alpha) and interleukin 1 beta (IL 1 beta) and applied these successfully to the measurement of interleukin 1 (IL 1) in neat plasma. Further characterization of the plasma immunoreactive forms of IL 1 was done using Sephadex G-75 chromatography and TSKG2000 high performance gel permeation chromatography. This revealed the immunoreactivity to be associated with a high molecular weight fraction for both IL 1 alpha and IL 1 beta. Incubation of plasma with iodinated IL 1 alpha and beta showed that there was a time-dependent association of tracer with the high molecular weight fraction and that this was predominantly with IL 1 beta. The activity was displaceable with unlabeled IL 1 beta, which together with the chromatography results, suggested that IL 1 beta is protein-bound in plasma. Furthermore, we have shown that under acid conditions both tracer and endogenous IL 1 beta immunoreactivity migrate as a low (17 kD) molecular weight fraction. This suggests that dissociation from a high molecular weight binder has occurred. Acid treatment of plasma raised the immunoreactive IL 1 beta level, but had no effect on IL 1 alpha levels, confirming the specificity of a binder to IL 1 beta, as shown by the tracer experiments. These results suggest that plasma contains high molecular weight binders of IL 1, particularly IL 1 beta, and that these may play a role in regulating the distribution, clearance and bioactivity of circulating IL 1. |
Databáze: |
MEDLINE |
Externí odkaz: |
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