The acylation state of mycobacterial lipomannans modulates innate immunity response through toll-like receptor 2.
Detection of Mycobacterium tuberculosis antigens by professional phagocytes via toll-like receptors (TLR) contributes to controlling chronic M. tuberculosis infection. Lipomannans (LM), which are major lipoglycans of the mycobacterial envelope, were recently described as agonists of TLR2 with potent activity on proinflammatory cytokine regulation. LM correspond to a heterogeneous population of acyl- and glyco-forms. We report here the purification and the complete structural characterization of four LM acyl-forms from Mycobacterium bovis BCG using MALDI MS and 2D (1)H-(31)P NMR analyses. All this biochemical work provided the tools to investigate the implication of LM acylation degree on its proinflammatory activity. The latter was ascribed to the triacylated LM form, essentially an agonist of TLR2, using TLR2/TLR1 heterodimers for signaling. Altogether, these findings shed more light on the molecular basis of LM recognition by TLR.
Gilleron
Martine
M
Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, Toulouse, France.
Nigou
Jérôme
J
Nicolle
Delphine
D
Quesniaux
Valérie
V
Puzo
Germain
G
D000215:Acylation; D000818:Animals; D002236:Carbohydrate Conformation; D002478:Cells, Cultured; D019281:Dimerization; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects* / Q000276:immunology*; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D018345:Mice, Knockout; D009163:Mycobacterium bovis / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D051195:Toll-Like Receptor 2 / Q000172:deficiency / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D051197:Toll-Like Receptor 4 / Q000172:deficiency / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000378:metabolism
D008070:Lipopolysaccharides; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; C064351:lipomannan