Synthesis and in vitro activities of a spacer-containing glycophospholipid ligand of a lipopolysaccharide receptor involved in endotoxin tolerance.
A glycophospholipid consisting in a derivative of N,N'-acylated and bisphosphorylated 2,3-dideoxy-2,3-diamino-D-glucose, bearing a 6-aminocaproyl side chain as spacer arm at carbon 6 (PPDm2-B), has been synthesized and its effect on murine macrophages evaluated. The synthesis started from 2,3-diamino-D-glucose, which was best obtained from glucosamine essentially by known procedures, since attempts to use another known precursor (3-nitroglycoside) led to unexpected results. Selective N-acylation was performed with the hydroxysuccinimide ester of (D)-3-benzyloxymyritic acid followed by esterification of the sole primary hydroxyl function by 6-azidocaproylchloride and phosphorylation of the resulting 1,4-diol by treatment with tetrabenzyl pyrophosphate. Hydrogenation on a Pd on carbon catalyst permitted the isolation of 6-(6-aminohexanoyl)-2,3-dideoxy-2,3-di-[(R)-3-hydroxy-tetradecanamido ] -alpha-D-glucopyranose 1,4-diphosphate (PPDm2-B). In mouse macrophages, PPDm2-B enhanced the lipopolysaccharide (LPS)-dependent secretion of tumor necrosis factor alpha (TNF-alpha), and inhibited the LPS-induced desensitization of these cells. The data suggest that PPDm2-B interacts in a serum-independent way with an LPS receptor different from CD14, and involved in endotoxin tolerance. Binding studies of a fluorescent derivative of PPDm2-B indicated that the expression of this unknown receptor is down-regulated during in vitro culture of the cells. Owing to its spacer arm, PPDm2-B could thus be a promising tool for future studies of this receptor.
Charon
D
D
Equipe Endotoxines, Centre National de la Recherche Scientifique, Université de Paris-Sud, Centre d'Etudes Pharmaceutiques, Châtenay-Malabry, France.
Mondange
M
M
Pons
J F
JF
Blay
K L
KL
Chaby
R
R
D000818:Animals; D002460:Cell Line; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D066298:In Vitro Techniques; D008024:Ligands; D018950:Lipopolysaccharide Receptors / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000276:immunology / Q000633:toxicity*; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D051379:Mice; D009005:Monosaccharides / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D005456:Fluorescent Dyes; D008024:Ligands; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D009005:Monosaccharides; C114367:PPDm2 B; D014409:Tumor Necrosis Factor-alpha; D016650:Fluorescein-5-isothiocyanate