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Biomedical subjects

U Grunwald

Publications and source records attributed to U Grunwald.

4 recordsLinked to original sources

An enzyme-linked immunosorbent assay for the quantification of solubilized CD14 in biological fluids.

A simple and robust two site-binding ELISA for the quantification of solubilized CD14 in human and animal body fluids is described. The principle of the assay depends on the specific binding of sCD14 to two monoclonal antibodies (MEM-18, RoMo-1) recognizing different epitopes of this glycoprotein. The detection limit for sCD14 was 1 ng/ml. The method was used to quantify sCD14 in different biological fluids, giving an intra-assay coefficient of variation and an interassay coefficient of variation of about 9%. The assay was used to measure sCD14 in human serum and plasma and other body fluids in health and disease, and in cell culture supernatants. With the exception of monkeys there was no reactivity with 29 other species screened. In healthy volunteers the sCD14 serum level had a mean value of 3.98 +/- 0.3 micrograms/ml (mean SEM, n = 102).

Antibodies, Monoclonal

Endotoxin-neutralizing capacity of soluble CD14.

Luminol-enhanced chemiluminescence was used to determine the effect of soluble CD14 (sCD14) on the endotoxin-inducible generation of reactive oxygen species in human monocytes. It was necessary to mediate lipopolysaccharide (LPS) monocyte-activating capability by serum factors (LPS-binding proteins). sCD14 reduced LPS-inducible monocyte activation in a dose-dependent manner, even in the case of CD14- monocytes, obtained from a patient with paroxysmal nocturnal haemoglobinuria. These monocytes could be activated by opsonized LPS via other receptors. Using anti-mouse Ig-coated microbeads, it was demonstrated in FACS analysis that sCD14 mediates the binding of a mouse monoclonal anti-CD14 antibody (RoMo 1) to a complex of LPS/FITC (fluoroisothiocyanate) and a LPS-binding protein. The release of sCD14 from cultured monocytes was measured using LPS, TNF alpha (tumour necrosis factor), IL1, 4 and 6 (interleukin-1, -4 and -6) and IFN gamma (interferon-gamma) as stimulators. Addition of LPS and TNF alpha led to a dose-dependent increase in sCD14-levels in the culture supernatant, whereas IL1, IL6 and IFN gamma had no significant effect. IL4 dose-dependently depressed spontaneous sCD14 release. It is possible that elevated sCD14-serum levels in polytraumatized patients indicate a natural protective mechanism against excessive monocyte mediator production. Therefore, sCD14 may be a new therapeutic concept in endotoxic shock prevention.

Antigens, CD

[Binding of LPS to CD14].

The 53 kDa glycoprotein CD14 (cluster of differentiation No. 14, defined by monoclonal antibodies of the 1st Leukocyte Typing Workshop) is expressed on monocyte surfaces and was identified 1990 as an endotoxin receptor (1). The binding of endotoxin to CD14 was mediated by a LPS-binding protein (LBP) present in serum.

Animals