Coulombe, F. et al. Increased NOD2-mediated recognition of N-glycolyl muramyl dipeptide. J. Exp. Med. 206, 1709-1716

Department of Medicine, McGill University Health Centre, Montreal, Quebec H3G 1A4, Canada.
Journal of Experimental Medicine (Impact Factor: 12.52). 09/2009; 206(8):1709-16. DOI: 10.1084/jem.20081779
Source: PubMed


Peptidoglycan-derived muramyl dipeptide (MDP) activates innate immunity via the host sensor NOD2. Although MDP is N-acetylated in most bacteria, mycobacteria and related Actinomycetes convert their MDP to an N-glycolylated form through the action of N-acetyl muramic acid hydroxylase (NamH). We used a combination of bacterial genetics and synthetic chemistry to investigate whether N-glycolylation of MDP alters NOD2-mediated immunity. Upon infecting macrophages with 12 bacteria, tumor necrosis factor (TNF) alpha secretion was NOD2 dependent only with mycobacteria and other Actinomycetes (Nocardia and Rhodococcus). Disruption of namH in Mycobacterium smegmatis obrogated NOD2-mediated TNF secretion, which could be restored upon gene complementation. In mouse macrophages, N-glycolyl MDP was more potent than N-acetyl MDP at activating RIP2, nuclear factor kappaB, c-Jun N-terminal kinase, and proinflammatory cytokine secretion. In mice challenged intraperitoneally with live or killed mycobacteria, NOD2-dependent immune responses depended on the presence of bacterial namH. Finally, N-glycolyl MDP was more efficacious than N-acetyl MDP at inducing ovalbumin-specific T cell immunity in a model of adjuvancy. Our findings indicate that N-glycolyl MDP has a greater NOD2-stimulating activity than N-acetyl MDP, consistent with the historical observation attributing exceptional immunogenic activity to the mycobacterial cell wall.


Available from: Frederic Veyrier
  • Source
    • "PGNs, the main component in bacteria biofilm, consist of alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) glycan strands cross-linked by short peptides (Vollmer, Blanot, & de Pedro, 2008). Intact polymeric PGN, soluble PGN and a variety of PGN monomeric forms, including N-acetyl-muramyl-L-Ala-D-Glu-mDAP (M-TriDAP), PGN-derived muramyl dipeptide (MDP), N-acetyl MDP and N-glycolyl MDP are used to study the molecular mechanisms involved in the induction and repression of intestinal inflammation (Coulombe et al., 2009). Using HEK293 cell lines with PGN isolated from the Bacillus anthracis strain, researchers have found that primary innate immune cells respond efficiently to polymeric PGN, but not to PGN monomers (Iyer & Coggeshall, 2011). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Lactic acid bacteria (LAB) have long been used in the manufacture of yogurt and cheese. LAB inhabit the human gastrointestinal tract alongside dozens of varieties of gut bacteria, which play an essential role in modulating the innate immune response to gastrointestinal disorders. This research sought to provide a basis for the investigation of peptidoglycan (PGN) from Lactobacillus acidophilus (L. acidophilus) by macrophages phagocytosis related to the anti-inflammatory effect both in vitro and vivo. Results show that PGN, PGN hydrolysate and PGN monomer N-acetylmuramic acid (NAM) from L. acidophilus were found to have an anti-inflammatory effect on LPS-induced inflammation in RAW 264.7 cells, the profiling of iNOS mRNA levels was also inhibited in NAM-treated (100–300 µg/mL) group. The activation of the Nuclear factor κB (NF-κB) pathway is regulated by the cellular kinase p38 in mitogen-activated protein kinases (MAPK) upon NAM treatment (300 µg/mL). These findings were further supported in Escherichia coli (E. coli)-stimulated ICR mice, in which we found that oral administration of free L. acidophilus PGN and NAM from L. acidophilus exerted a potential anti-inflammatory response. NAM, as the main components of the LAB cell wall, will be a candidate for pharmaceutical application of anti-inflammatory drugs.
    Journal of Functional Foods 03/2015; 13. DOI:10.1016/j.jff.2014.12.048 · 3.57 Impact Factor
  • Source
    • "Mycobacterial extracts have been widely used in vaccine developments, including the use of Freund’s complete adjuvant (FCA), which contains fragments from the mycobacteria. In particular, the mycobacterial cell wall contains a variety of antigenic and immunostimulatory molecules, such as peptidoglycan, arabinogalactan, mycolic acids, proteins, phosphatidylinositol mannosides, tiocerol, lipomanann, and lipoarabinomann, which activate dendritic cells via mannose and NOD2 receptors, among others (44, 45). All these components are important molecular effectors involved in the infection process and have been reported to induce protective responses in mice against TB (46, 47). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Vaccines based on outer membrane vesicles (OMV) were developed more than 20 years ago against Neisseria meningitidis serogroup B. These nano-sized structures exhibit remarkable potential for immunomodulation of immune responses and delivery of meningococcal antigens or unrelated antigens incorporated into the vesicle structure. This paper reviews different applications in OMV Research and Development (R&D) and provides examples of OMV developed and evaluated at the Finlay Institute in Cuba. A Good Manufacturing Practice (GMP) process was developed at the Finlay Institute to produce OMV from N. meningitidis serogroup B (dOMVB) using detergent extraction. Subsequently, OMV from N. meningitidis, serogroup A (dOMVA), serogroup W (dOMVW), and serogroup X (dOMVX) were obtained using this process. More recently, the extraction process has also been applied effectively for obtaining OMV on a research scale from Vibrio cholerae (dOMVC), Bordetella pertussis (dOMVBP), Mycobacterium smegmatis (dOMVSM), and BCG (dOMVBCG). The immunogenicity of the OMV has been evaluated for specific antibody induction, and together with functional bactericidal and challenge assays in mice has shown their protective potential. dOMVB has been evaluated with non-neisserial antigens, including with a herpes virus type 2 glycoprotein, ovalbumin, and allergens. In conclusion, OMV are proving to be more versatile than first conceived and remain an important technology for development of vaccine candidates.
    Frontiers in Immunology 03/2014; 5:121. DOI:10.3389/fimmu.2014.00121
  • Source
    • "In mycobacteria, a certain proportion of the muramic acid is N-glycolylated [13] through the activity of NamH, a UDP-N-acetylmuramic acid hydroxylase [14]. This modification results in altered tumour necrosis factor α production [15,16] however, abrogation of NamH activity does not lead to decreased virulence in mice [16]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Mycobacteria comprise diverse species including non-pathogenic, environmental organisms, animal disease agents and human pathogens, notably Mycobacterium tuberculosis. Considering that the mycobacterial cell wall constitutes a significant barrier to drug penetration, the aim of this study was to conduct a comparative genomics analysis of the repertoire of enzymes involved in peptidoglycan (PG) remodelling to determine the potential of exploiting this area of bacterial metabolism for the discovery of new drug targets. We conducted an in silico analysis of 19 mycobacterial species/clinical strains for the presence of genes encoding resuscitation promoting factors (Rpfs), penicillin binding proteins, endopeptidases, L,D-transpeptidases and N-acetylmuramoyl-L-alanine amidases. Our analysis reveals extensive genetic multiplicity, allowing for classification of mycobacterial species into three main categories, primarily based on their rpf gene complement. These include the M. tuberculosis Complex (MTBC), other pathogenic mycobacteria and environmental species. The complement of these genes within the MTBC and other mycobacterial pathogens is highly conserved. In contrast, environmental strains display significant genetic expansion in most of these gene families. Mycobacterium leprae retains more than one functional gene from each enzyme family, underscoring the importance of genetic multiplicity for PG remodelling. Notably, the highest degree of conservation is observed for N-acetylmuramoyl-L-alanine amidases suggesting that these enzymes are essential for growth and survival. PG remodelling enzymes in a range of mycobacterial species are associated with extensive genetic multiplicity, suggesting functional diversification within these families of enzymes to allow organisms to adapt.
    BMC Microbiology 03/2014; 14(1):75. DOI:10.1186/1471-2180-14-75 · 2.73 Impact Factor
Show more