The M20 IL-1 inhibitor. II. Biological characterization.
Interleukin-1 (IL-1) is an important mediator in inflammation and immunological processes. The findings of native IL-1 inhibitors suggest a negative feedback mechanism to down-regulate IL-1 mediated acute inflammation. IL-1 inhibitors were also found elevated in disease states associated with high IL-1 levels. We have previously described one such IL-1 inhibitor derived from the human M20 myelomonocytic cell line. In this paper we present several biological and biochemical characteristics of the M20 IL-1 inhibitor. Various in vitro activities of the inhibitor are described and its IL-1 specificity in these assays is demonstrated. Purification of the inhibitor was performed by DEAE-high performance liquid chromatography, isoelectric focusing, gel filtration and dye ligand chromatography column. This protein factor has a MW of 52 +/- 4 kDa and a pI of 4.15 +/- 0.1. The inhibitor has no cross-reactivity against a panel of known cytokines (IL-1 alpha, IL-1 beta, IL-2, sIL-2R, IL-6, tumor necrosis factor (TNF), interferon-gamma (IFN-gamma)) and is distinct from the IL-1 receptor antagonist (IL-1ra). The purified IL-1 inhibitor was destroyed by trypsin, 2-mercaptoethanol, sodium dodecyl sulfate and extremes in pH and in temperature. Only IL-1 induced (but not the IL-2, IL-6 or TNF induced) thymocyte proliferation and PGE2 production by fibroblasts were inhibited by the inhibitor, thus showing specificity to IL-1 in these assays.
Peritt
D
D
Oncology Department, Hadassah University Hospital, Jerusalem, Israel.
Flechner
I
I
Yanai
P
P
Okunev
E
E
Halperin
T
T
Treves
A J
AJ
Barak
V
V
D001681:Biological Assay; D002460:Cell Line; D016207:Cytokines / Q000737:chemistry / Q000276:immunology* / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007375:Interleukin-1 / Q000037:antagonists & inhibitors*; D008213:Lymphocyte Activation / Q000187:drug effects; D008623:Mercaptoethanol / Q000494:pharmacology; D009000:Monocytes / Q000737:chemistry*; D011489:Protein Denaturation; D013696:Temperature; D014357:Trypsin / Q000494:pharmacology
D016207:Cytokines; D007375:Interleukin-1; D008623:Mercaptoethanol; D014357:Trypsin