Mycobacterial Nucleoside Diphosphate Kinase Blocks Phagosome Maturation in Murine Raw 264.7 Macrophages
Open Access
- 19 January 2010
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 5 (1), e8769
- https://doi.org/10.1371/journal.pone.0008769
Abstract
Microorganisms capable of surviving within macrophages are rare, but represent very successful pathogens. One of them is Mycobacterium tuberculosis (Mtb) whose resistance to early mechanisms of macrophage killing and failure of its phagosomes to fuse with lysosomes causes tuberculosis (TB) disease in humans. Thus, defining the mechanisms of phagosome maturation arrest and identifying mycobacterial factors responsible for it are key to rational design of novel drugs for the treatment of TB. Previous studies have shown that Mtb and the related vaccine strain, M. bovis bacille Calmette-Guérin (BCG), disrupt the normal function of host Rab5 and Rab7, two small GTPases that are instrumental in the control of phagosome fusion with early endosomes and late endosomes/lysosomes respectively. Here we show that recombinant Mtb nucleoside diphosphate kinase (Ndk) exhibits GTPase activating protein (GAP) activity towards Rab5 and Rab7. Then, using a model of latex bead phagosomes, we demonstrated that Ndk inhibits phagosome maturation and fusion with lysosomes in murine RAW 264.7 macrophages. Maturation arrest of phagosomes containing Ndk-beads was associated with the inactivation of both Rab5 and Rab7 as evidenced by the lack of recruitment of their respective effectors EEA1 (early endosome antigen 1) and RILP (Rab7-interacting lysosomal protein). Consistent with these findings, macrophage infection with an Ndk knocked-down BCG strain resulted in increased fusion of its phagosome with lysosomes along with decreased survival of the mutant. Our findings provide evidence in support of the hypothesis that mycobacterial Ndk is a putative virulence factor that inhibits phagosome maturation and promotes survival of mycobacteria within the macrophage.This publication has 60 references indexed in Scilit:
- Cell-Mediated Immune Responses in TuberculosisAnnual Review of Immunology, 2009
- Role of phosphatidylinositol 3-kinase and Rab5 effectors in phagosomal biogenesis and mycobacterial phagosome maturation arrestThe Journal of cell biology, 2001
- Rab-interacting lysosomal protein (RILP): the Rab7 effector required for transport to lysosomesThe EMBO Journal, 2001
- Identification of Mycobacterial Surface Proteins Released into Subcellular Compartments of Infected MacrophagesInfection and Immunity, 2000
- Mycobacterium tuberculosisandLegionella pneumophilaPhagosomes Exhibit Arrested Maturation despite Acquisition of Rab7Infection and Immunity, 2000
- GAP activity of the Yersinia YopE cytotoxin specifically targets the Rho pathway: a mechanism for disruption of actin microfilament structureMolecular Microbiology, 2000
- Rab7: A Key to Lysosome BiogenesisMolecular Biology of the Cell, 2000
- Mycobacterial infection of macrophages results in membrane-permeable phagosomesProceedings of the National Academy of Sciences of the United States of America, 1999
- Phagocytic processing of antigens for presentation by class II major histocompatibility complex moleculesCellular Microbiology, 1999
- Phosphatidylinositol-3-OH kinases are Rab5 effectorsNature, 1999