Trehalose Dimycolate (Cord Factor) as a Contributing Factor to Tuberculosis Pathogenesis

2019 ◽  
pp. 43-61 ◽  
Author(s):  
Jeffrey K. Actor
Keyword(s):  
Trehalose Dimycolate ◽  
Cord Factor

scholarly journals Microscopic Cords, a Virulence-Related Characteristic of Mycobacterium tuberculosis, Are Also Present in Nonpathogenic Mycobacteria

2010 ◽  
Vol 192 (7) ◽  
pp. 1751-1760 ◽  
Author(s):  
Esther Julián ◽  
Mónica Roldán ◽  
Alejandro Sánchez-Chardi ◽  
Oihane Astola ◽  
Gemma Agustí ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Trehalose Dimycolate ◽  
Cord Factor ◽  
Ideal Tool ◽  
Colonial Morphology ◽  
Related Characteristic ◽  
Microscopy Images ◽  
Scanning Electron ◽  
The Ideal

ABSTRACT The aggregation of mycobacterial cells in a definite order, forming microscopic structures that resemble cords, is known as cord formation, or cording, and is considered a virulence factor in the M ycobacterium tuberculosis complex and the species M ycobacterium marinum. In the 1950s, cording was related to a trehalose dimycolate lipid that, consequently, was named the cord factor. However, modern techniques of microbial genetics have revealed that cording can be affected by mutations in genes not directly involved in trehalose dimycolate biosynthesis. Therefore, questions such as “How does mycobacterial cord formation occur?” and “Which molecular factors play a role in cord formation?” remain unanswered. At present, one of the problems in cording studies is the correct interpretation of cording morphology. Using optical microscopy, it is sometimes difficult to distinguish between cording and clumping, which is a general property of mycobacteria due to their hydrophobic surfaces. In this work, we provide a new way to visualize cords in great detail using scanning electron microscopy, and we show the first scanning electron microscopy images of the ultrastructure of mycobacterial cords, making this technique the ideal tool for cording studies. This technique has enabled us to affirm that nonpathogenic mycobacteria also form microscopic cords. Finally, we demonstrate that a strong correlation exists between microscopic cords, rough colonial morphology, and increased persistence of mycobacteria inside macrophages.

scholarly journals Discovery of Salmonella trehalose phospholipids reveals functional convergence with mycobacteria

2019 ◽  
Vol 216 (4) ◽  
pp. 757-771 ◽  
Author(s):  
Peter Reinink ◽  
Jeffrey Buter ◽  
Vivek K. Mishra ◽  
Eri Ishikawa ◽  
Tan-Yun Cheng ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bacterial Species ◽  
Specific Cell ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Trehalose Dimycolate ◽  
Functional Convergence ◽  
Cord Factor ◽  
Cardiolipin Synthase ◽  
Activating Receptor

Salmonella species are among the world’s most prevalent pathogens. Because the cell wall interfaces with the host, we designed a lipidomics approach to reveal pathogen-specific cell wall compounds. Among the molecules differentially expressed between Salmonella Paratyphi and S. Typhi, we focused on lipids that are enriched in S. Typhi, because it causes typhoid fever. We discovered a previously unknown family of trehalose phospholipids, 6,6′-diphosphatidyltrehalose (diPT) and 6-phosphatidyltrehalose (PT). Cardiolipin synthase B (ClsB) is essential for PT and diPT but not for cardiolipin biosynthesis. Chemotyping outperformed clsB homology analysis in evaluating synthesis of diPT. DiPT is restricted to a subset of Gram-negative bacteria: large amounts are produced by S. Typhi, lower amounts by other pathogens, and variable amounts by Escherichia coli strains. DiPT activates Mincle, a macrophage activating receptor that also recognizes mycobacterial cord factor (6,6′-trehalose dimycolate). Thus, Gram-negative bacteria show convergent function with mycobacteria. Overall, we discovered a previously unknown immunostimulant that is selectively expressed among medically important bacterial species.

scholarly journals Biosynthesis and Virulent Behavior of Lipids Produced by Mycobacterium tuberculosis: LAM and Cord Factor: An Overview

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Rajni ◽  
Nisha Rao ◽  
Laxman S. Meena
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Host Cell ◽  
Phosphatidyl Inositol ◽  
Polymorphonuclear Neutrophils ◽  
Host Cells ◽  
Wall Structure ◽  
Trehalose Dimycolate ◽  
Cell Immunity ◽  
Cord Factor

Mycobacterium tuberculosis is the causative agent of tuberculosis disease, which has developed a myriad of exceptional features contributing to its survival within the hostile environment of host cell. Unique cell wall structure with high lipid content plays an imperative role in the pathogenicity of mycobacteria. Cell wall components of MTB such as lipoarabinomannan and Trehalose dimycolate (cord factor) are virulent in nature apart from its virulence genes. Virulent effect of these factors on host cells reduces host cell immunity. LAM has been known to inhibit phagosome maturation by inhibiting the Ca2+/calmodulin phosphatidyl inositol-3-kinase hvps34 pathways. Moreover, TDM (Trehalose dimycolate) also inhibits fusion between phospholipid vesicles and migration of polymorphonuclear neutrophils. The objective of this paper is to understand the virulence of LAM and cord factor on host cell which might be helpful to design an effective drug against tuberculosis.

The role of trehalose dimycolate (cord factor) on morphology of virulent M. tuberculosis in vitro

Tuberculosis ◽  
2006 ◽  
Vol 86 (5) ◽  
pp. 349-356 ◽  
Author(s):  
Robert Lee Hunter ◽  
Nandagopal Venkataprasad ◽  
Margaret R. Olsen
Keyword(s):  
Trehalose Dimycolate ◽  
Cord Factor

scholarly journals The molecular biology of mycobacterial trehalose in the quest for advanced tuberculosis therapies

Microbiology ◽  
2014 ◽  
Vol 160 (8) ◽  
pp. 1547-1570 ◽  
Author(s):  
Ana Nobre ◽  
Susana Alarico ◽  
Ana Maranha ◽  
Vitor Mendes ◽  
Nuno Empadinhas
Keyword(s):  
Cell Envelope ◽  
New Drugs ◽  
Diagnostic Tools ◽  
Lead Compounds ◽  
Trehalose Dimycolate ◽  
Immunodeficiency Virus ◽  
Cord Factor ◽  
Domains Of Life ◽  
Trehalose Biosynthesis ◽  
The 19Th Century

Trehalose is a natural glucose disaccharide identified in the 19th century in fungi and insect cocoons, and later across the three domains of life. In members of the genus Mycobacterium, which includes the tuberculosis (TB) pathogen and over 160 species of nontuberculous mycobacteria (NTM), many of which are opportunistic pathogens, trehalose has been an important focus of research over the last 60 years. It is a crucial player in the assembly and architecture of the remarkable mycobacterial cell envelope as an element of unique highly antigenic glycolipids, namely trehalose dimycolate (‘cord factor’). Free trehalose has been detected in the mycobacterial cytoplasm and occasionally in oligosaccharides with unknown function. TB and NTM infection statistics and death toll, the decline in immune responses in the aging population, human immunodeficiency virus/AIDS or other debilitating conditions, and the proliferation of strains with different levels of resistance to the dated drugs in use, all merge into a serious public-health threat urging more effective vaccines, efficient diagnostic tools and new drugs. This review deals with the latest findings on mycobacterial trehalose biosynthesis, catabolism, processing and recycling, as well with the ongoing quest for novel trehalose-related mechanisms to be targeted by novel TB therapeutics. In this context, the drug-discovery pipeline has recently included new lead compounds directed toward trehalose-related targets highlighting the potential of these pathways to stem the tide of rising drug resistance.

scholarly journals Identification of trehalose dimycolate (cord factor) inMycobacterium leprae

FEBS Letters ◽  
2007 ◽  
Vol 581 (18) ◽  
pp. 3345-3350 ◽  
Author(s):  
Masanori Kai ◽  
Yukiko Fujita ◽  
Yumi Maeda ◽  
Noboru Nakata ◽  
Shinzo Izumi ◽  
...  
Keyword(s):  
Trehalose Dimycolate ◽  
Cord Factor

scholarly journals Direct recognition of the mycobacterial glycolipid, trehalose dimycolate, by C-type lectin Mincle

2009 ◽  
Vol 206 (13) ◽  
pp. 2879-2888 ◽  
Author(s):  
Eri Ishikawa ◽  
Tetsuaki Ishikawa ◽  
Yasu S. Morita ◽  
Kenji Toyonaga ◽  
Hisakata Yamada ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Host Immune System ◽  
Activated Macrophages ◽  
Fatal Disease ◽  
Trehalose Dimycolate ◽  
Cord Factor ◽  
Mycobacterial Cell Wall ◽  
Direct Recognition ◽  
Deficient Mice

Tuberculosis remains a fatal disease caused by Mycobacterium tuberculosis, which contains various unique components that affect the host immune system. Trehalose-6,6′-dimycolate (TDM; also called cord factor) is a mycobacterial cell wall glycolipid that is the most studied immunostimulatory component of M. tuberculosis. Despite five decades of research on TDM, its host receptor has not been clearly identified. Here, we demonstrate that macrophage inducible C-type lectin (Mincle) is an essential receptor for TDM. Heat-killed mycobacteria activated Mincle-expressing cells, but the activity was lost upon delipidation of the bacteria; analysis of the lipid extracts identified TDM as a Mincle ligand. TDM activated macrophages to produce inflammatory cytokines and nitric oxide, which are completely suppressed in Mincle-deficient macrophages. In vivo TDM administration induced a robust elevation of inflammatory cytokines in sera and characteristic lung inflammation, such as granuloma formation. However, no TDM-induced lung granuloma was formed in Mincle-deficient mice. Whole mycobacteria were able to activate macrophages even in MyD88-deficient background, but the activation was significantly diminished in Mincle/MyD88 double-deficient macrophages. These results demonstrate that Mincle is an essential receptor for the mycobacterial glycolipid, TDM.

Synthesis of trehalose dimycolate (cord factor) by a cell-free system of Mycobacteriumsmegmatis

1982 ◽  
Vol 108 (1) ◽  
pp. 132-139 ◽  
Author(s):  
James O. Kilburn ◽  
Kuni Takayama ◽  
Emma Lee Armstrong
Keyword(s):  
Free System ◽  
Cell Free System ◽  
Trehalose Dimycolate ◽  
Cord Factor ◽  
A Cell
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