Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously shown that an ectoenzyme, NAD glycohydrolase (NADase) could be solubilized by treatment with bacterial phosphatidylinositol phospholipase C (PIPLC). However, it is unknown whether endogenous PIPLC can cleave this ectoenzyme. In this study, we used mouse peritoneal exudate macrophages which have been known to have relatively high activity of NADase. The results show that release of ecto-NADase was markedly increased when mouse peritoneal macrophages were costimulated with interferon-gamma (IFN-gamma) and bacterial lipopolysaccharide (LPS), compared to unstimulated cells. This increase was preceded by markedly enhanced activity of endogenous glycosylphosphatidylinositol phospholipase C (GPIPLC). The cross-reacting determinant (CRD) of the glycosylphosphatidylinositol anchor in released NADase from activated macrophages was detected by immunoblotting with anti-CRD antibody. Taken together, ecto-NADase is release from peritoneal exudate macrophages during IFN-gamma/LPS-induced activation and endogenous GPIPLC is involved in the NADase release from the activated macrophages.
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PMID:Glycosylphosphatidylinositol-anchored NAD glycohydrolase is released from peritoneal macrophages activated by interferon-gamma and lipopolysaccharide. 799 54

Using flow cytometry we have compared the binding of Neisseria meningitidis lipopolysaccharide labeled with fluorescein isothiocyanate (FITC-LPS) to normal human monocytes in whole blood with the binding to chinese hamster ovary (CHO) cells transfected with human CD14 gene (hCD14-CHO cells). Binding of FITC-LPS to cells was dose dependent, saturable and enhanced in the presence of increasing concentrations of serum. Blockade of membrane CD14 with saturating concentrations of anti-CD14 monoclonal antibody (mAb) My4 inhibited 50% of the binding of FITC-LPS to monocytes and 100% to hCD14-CHO cells. Similarly, removal of membrane CD14 by phosphatidylinositol phospholipase C (PI-PLC) treatment of the cells partially decreased the binding of FITC-LPS to monocytes but totally inhibited the binding to hCD14-CHO-transfected cells. These results suggest that binding of FITC-LPS to monocytes is not only mediated by membrane CD14. Using two-color flow cytometry, we observed that FITC-LPS binds to My4-saturated monocytes in association with soluble (s)CD14 present in serum as revealed by staining with rhodamine-labeled My4 mAb. The binding of FITC-LPS/sCD14 complexes to monocytes treated with saturating amounts of unlabeled My4 prior to addition of the complexes was completely inhibited by anti-CD14 mAb 10G33. When cells were first saturated with a mixture of My4 and 10G33 mAb, washed and further incubated with FITC-LPS/sCD14, inhibition of the binding of LPS was similar to that observed with cells saturated with My4 alone, showing that the binding of FITC-LPS is not mediated by the 10G33 epitope present on mCD14. These results suggest that either the 10G33 epitope on sCD14 is involved in the binding of LPS/sCD14 complexes to the cells, or that 10G33 mAb inhibits the binding of FITC-LPS to sCD14. Taken together, these data indicate that sCD14 which is present in normal serum, in addition to membrane CD14, enables LPS to bind monocytes through an as yet unidentified molecule and that sCD14 does not simply serve as a shuttle for transfer of LPS to membrane CD14.
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PMID:Lipopolysaccharide complexed with soluble CD14 binds to normal human monocytes. 946 18