Lipids of Pathogenic Mycobacteria: Contributions to Virulence and Host Immune Suppression

Institut Pasteur, Unité Postulante Pathogénomique Mycobactérienne Intégrée, Paris, France.
Transboundary and Emerging Diseases (Impact Factor: 2.94). 06/2009; 56(6-7):255-68. DOI: 10.1111/j.1865-1682.2009.01072.x
Source: PubMed


Mycobacteria are characterized by a complex cell wall, the lipid nature of which confers to the bacilli resistance to drying, acid or alkaline conditions, and to chemical disinfectants and therapeutic agents. Pathogenic species, such as Mycobacterium tuberculosis, M. leprae and M. ulcerans, have evolved various strategies to establish residence in their hosts and provoke long-term infections. There is mounting evidence that the unique lipids composing their envelopes, strategically located at the host-pathogen interface, contribute to their escape from immune surveillance. Here, the chemical structure, host cell receptors and biological actions of this emerging class of mycobacterial virulence factors are reviewed.

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Available from: Caroline Demangel, Apr 18, 2014
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    • "PGLs are only produced by the members of the MTBC and related slow-growing mycobacteria, yet even among the mycobacteria that make PGL; there are species-specific modifications in the carbohydrate moiety [Daffe and Laneelle, 1988; Onwueme et al., 2005; schematically illustrated in (Veyrier et al., 2011)]. The PGLs have been implicated in mycobacterial pathogenicity such as oxidative stress resistance (Chan et al., 1989), cell tropism (Ng et al., 2000; Rambukkana, 2001), and immunomodulation (Reed et al., 2004; Guenin-Mace et al., 2009; Cambier et al., 2014). "
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    Frontiers in Microbiology 04/2014; 5:139. DOI:10.3389/fmicb.2014.00139 · 3.99 Impact Factor
    • "[4]. The complex cell wall of mycobacteria contains unusual lipids that are essential for survival and virulence [5] [6]. In addition, the cytosol of mycobacteria contains organites (lipid inclusion bodies) that store important lipids [triacylglycerol (TAG)] for long-term survival during the dormancy phase [7]. "
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    • "e unique lipids composing the cell envelope of pathogenic mycobacteria such as lipoarabinomannan (LAM), lipomannan (LM), phosphatidylinositol mannoside (PIM), and trehalose 6,6 ′ -dimycolate (TDM) interact with membrane CD14 (mCD14) and TLR2 on macrophages and activate signaling pathways inducing the innate immune response to infection [6] [7] [11] [12]. A soluble form of plasma CD14 (sCD14) is known to sensitize host cells to LPS; however, it also interacts with mycobacterial LAM causing upregulated endogenous CD14 gene expression [13]. "
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