Cell biology of mycobacterium tuberculosis phagosome.
Phagocytosis and phagolysosome biogenesis represent fundamental biological processes essential for proper tissue homeostasis, development, elimination of invading microorganisms, and antigen processing and presentation. Phagosome formation triggers a preprogrammed pathway of maturation into the phagolysosome, a process controlled by Ca2+ and the regulators of organellar trafficking centered around the small GTP-binding proteins Rabs and their downstream effectors, including lipid kinases, organellar tethering molecules, and membrane fusion apparatus. Mycobacterium tuberculosis is a potent human pathogen parasitizing macrophages. It interferes with the Rab-controlled membrane trafficking and arrests the maturing phagosome at a stage where no harm can be done to the pathogen while the delivery of nutrients and membrane to the vacuole harboring the microorganism continues. This process, referred to as the M. tuberculosis phagosome maturation arrest or inhibition of phagosome-lysosome fusion, is critical for M. tuberculosis persistence in human populations. It also provides a general model system for dissecting the phagolysosome biogenesis pathways. Here we review the fundamental trafficking processes targeted by M. tuberculosis and the mycobacterial products that interfere with phagosomal maturation.
Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131-001, USA. ivergne@salud.unm.edu
Isabelle
I
Vergne
Jennifer
J
Chua
Sudha B
SB
Singh
Vojo
V
Deretic
D001692:Biological Transport; D002118:Calcium / Q000378:metabolism; D006801:Humans; D008264:Macrophages / Q000378:metabolism / Q000382:microbiology*; D009169:Mycobacterium tuberculosis / Q000378:metabolism / Q000472:pathogenicity*; D010587:Phagocytosis / Q000502:physiology; D010588:Phagosomes / Q000378:metabolism / Q000382:microbiology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D048051:p38 Mitogen-Activated Protein Kinases; D002118:Calcium