Early Intracellular Trafficking of Granulibacter bethesdensis in Human Macrophages.
Granulibacter bethesdensisis a Gram-negative bacterium that infects patients with chronic granulomatous disease (CGD), a primary immunodeficiency marked by a defect in NOX2, the phagocyte NADPH oxidase. Previous studies have shown that NOX2 is essential for killing ofG. bethesdensisby neutrophils and monocytes and that the bacteriostatic activity of monocyte-derived macrophages (MDM) requires NOX2 and gamma interferon (IFN-γ) pretreatment. To determine whetherG. bethesdensisevades phagolysosomal killing, a host defense pathway intact in both normal and CGD MDM, or whether it occupies a distinct intracellular niche in CGD MDM, we assessed the trafficking patterns of this organism. We observed colocalization ofG. bethesdensiswith an early endosome antigen 1 (EEA1)-positive compartment, followed by colocalization with lysosome-associated membrane protein 1 (LAMP1)-positive and LysoTracker-positive late phagosomes; these characteristics were similar in both normal and CGD MDM. Despite localization to acidified late phagosomes, viableG. bethesdensiscells were recovered from viable MDM in numbers greater than in the initial input up to 6 days after infection.G. bethesdensisremains, and in some cases appears to divide, within a membrane-bound compartment for the entire 6-day time course. These findings indicate that this organism resists both oxygen-dependent and oxygen-independent phagolysosomal antimicrobial systems of human macrophages.
Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
Jessica
J
Chu
Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
Margery G
MG
Smelkinson
Electron Microscopy Unit, Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA.
David W
DW
Dorward
Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
Kol A
KA
Zarember
Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA jgallin@cc.nih.gov.
John I
JI
Gallin
D016947:Acetobacteraceae / Q000472:pathogenicity*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006105:Granulomatous Disease, Chronic / Q000150:complications / Q000382:microbiology*; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology; D051907:Lysosomal Membrane Proteins / Q000378:metabolism; D008264:Macrophages / Q000382:microbiology* / Q000648:ultrastructure; D008562:Membrane Glycoproteins / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D009000:Monocytes / Q000382:microbiology; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000378:metabolism; D009504:Neutrophils / Q000382:microbiology; D010587:Phagocytosis; D010588:Phagosomes / Q000276:immunology / Q000382:microbiology; D033921:Vesicular Transport Proteins / Q000378:metabolism; D052118:Lysosomal-Associated Membrane Protein 1
D007371:Interferon-gamma; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D033921:Vesicular Transport Proteins; C489116:LAMP1 protein, human; D052118:Lysosomal-Associated Membrane Protein 1; C093846:early endosome antigen 1; C056558:CYBB protein, human
Gram-negative bacteria; Granulibacter; chronic granulomatous disease; innate immunity; macrophages; microbial pathogenesis; vesicular trafficking