La protéine de liaison au lipopolysaccharide (ou Lipopolysaccharide Binding Protein) est une protéine qui, chez l’homme, est codée par le gèneLBP[5] situé sur le chromosome 20 humain.
La protéine codée par ce gène est impliquée dans la réponse immunologique en phase aiguë aux infections bactériennes à Gram négatif. Les bactéries à Gram négatif contiennent un glycolipide, un lipopolysaccharide (LPS), sur leur paroi cellulaire externe. Avec la protéine augmentant la perméabilité bactéricide (BPI ou batericidal permeability-increasing protein), la protéine codée se lie au LPS et interagit avec le récepteur CD14, jouant probablement un rôle dans la régulation des réponses des monocytes dépendant du LPS. Des études chez la souris suggèrent que la protéine codée est nécessaire à la réponse rapide du LPS en phase aiguë, mais pas à la clairance du LPS de la circulation. Cette protéine fait partie d'une famille de protéines structurellement et fonctionnellement liées, notamment la BPI, la protéine de transfert de cholestérol ester plasmatique (CETP) et la protéine de transfert de phospholipides (PLTP). Enfin, ce gène se trouve sur le chromosome 20, immédiatement en aval du gène BPI.
Interactions
Il a été démontré que la protéine liant les lipopolysaccharides interagissait avec CD14,TLR2, TLR4 et le co-récepteur MD-2[7],[8],[9].
↑« The genes for the lipopolysaccharide binding protein (LBP) and the bactericidal permeability increasing protein (BPI) are encoded in the same region of human chromosome 20 », Genomics, vol. 15, no 1, , p. 188–90 (PMID8432532, DOI10.1006/geno.1993.1030)
↑« Essential roles of CD14 and lipopolysaccharide-binding protein for activation of toll-like receptor (TLR)2 as well as TLR4 Reconstitution of TLR2- and TLR4-activation by distinguishable ligands in LPS preparations », Eur. J. Biochem., vol. 268, no 16, , p. 4580–9 (PMID11502220, DOI10.1046/j.1432-1327.2001.02385.x)
↑Thomas, Kapoor Mili, Sharma Shilpi et Bausinger Huguette, « Evidence of a trimolecular complex involving LPS, LPS binding protein and soluble CD14 as an effector of LPS response », FEBS Lett., Netherlands, vol. 531, no 2, , p. 184–8 (ISSN0014-5793, PMID12417309, DOI10.1016/S0014-5793(02)03499-3)
↑Yu et Wright S D, « LPS-dependent interaction of Mac-2-binding protein with immobilized CD14 », J. Inflamm., UNITED STATES, vol. 45, no 2, , p. 115–25 (ISSN1078-7852, PMID7583357)
↑Erridge, Pridmore, Eley et Stewart, « Lipopolysaccharides of Bacteroides fragilis, Chlamydia trachomatis and Pseudomonas aeruginosa signal via toll-like receptor 2. », Journal of Medical Microbiology, vol. 53, no Pt 8, , p. 735–40 (PMID15272059, DOI10.1099/jmm.0.45598-0)
Bibliographie
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