C1 inhibitor prevents endotoxin shock via a direct interaction with lipopolysaccharide.

Autor: Liu D; Center for Blood Research, Children's Hospital, Harvard Medical School, 800 Huntington Avenue, Boston, MA 02115, USA., Cai S, Gu X, Scafidi J, Wu X, Davis AE 3rd
Jazyk: angličtina
Zdroj: Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2003 Sep 01; Vol. 171 (5), pp. 2594-601.
DOI: 10.4049/jimmunol.171.5.2594
Abstrakt: C1 inhibitor (C1INH) is beneficial in animal models of endotoxemia and sepsis. However, the mechanism(s) of C1INH protection remain(s) ill-defined. In this study, we demonstrated that both active C1INH and reactive center-cleaved, inactive C1INH protected mice from lethal Gram-negative endotoxemia. Both forms of C1INH blocked the LPS-binding protein-dependent binding of Salmonella typhimurium LPS to the murine macrophage cell line, RAW 264.7, and suppressed LPS-induced TNF-alpha mRNA expression. Inhibition of LPS binding to RAW 264.7 cells was reversed with anti-C1INH Ab and was more efficient when C1INH was incubated first with LPS rather than with the cells. C1INH also suppressed LPS-induced up-regulation of TNF-alpha mRNA in whole human blood. The interaction of C1INH with LPS was directly demonstrated both by ELISA and by nondenaturing PAGE, but deletion of the amino-terminal 97-aa residues abrogated this binding. Therefore, C1INH, in addition to its function as a serine protease inhibitor, has a novel anti-inflammatory function mediated via its heavily glycosylated amino-terminal non-serpin domain.
Databáze: MEDLINE