title: Elemental analysis of the Mycobacterium avium phagosome in Balb/c mouse macrophages.
abstract: Using a hard X-ray microprobe, we showed recently that in unstimulated peritoneal macrophages from C57BL/6 mice, the phagosome of pathogenic mycobacteria (Mycobacterium tuberculosis and Mycobacterium avium) can accumulate iron. We expanded our studies to the M. avium infection of peritoneal macrophages of Balb/c mice that show a similar degree of M. tuberculosis and M. avium-related chronic disease, but a higher susceptibility towards other intracellular pathogens such as Listeria monocytogenes, Leishmania major, or Brucella abortus as compared to C57BL/6 mice. Similar to C57BL/6 macrophages, the iron concentration in Balb/c macrophages increased significantly after 24 h of infection. A significant increase of the chlorine and potassium concentrations was observed in the Balb/c phagosomes between 1 and 24 h, in contrast with macrophages from C57BL/6 mice. The absolute elemental concentrations of calcium and zinc were higher in the mycobacterial phagosomes of Balb/c mice. We hypothesize that a potassium channel is abundant in the phagosome in macrophages that may be related to microbiocidal killing, similar to the requirement of potassium channels for microbiocidal function in neutrophils.
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, University of Freiburg, Freiburg, Germany. Dirk.Wagner@uniklinik-freiburg.de
authors.forename: Dirk
authors.initials: D
authors.lastname: Wagner
authors.forename: Jörg
authors.initials: J
authors.lastname: Maser
authors.forename: Ivana
authors.initials: I
authors.lastname: Moric
authors.forename: Stefan
authors.initials: S
authors.lastname: Vogt
authors.forename: Winfried V
authors.initials: WV
authors.lastname: Kern
authors.forename: Luiz E
authors.initials: LE
authors.lastname: Bermudez
mesh_terms: D000818:Animals; D002118:Calcium / Q000032:analysis / Q000378:metabolism; D002713:Chlorine / Q000032:analysis / Q000378:metabolism; D007501:Iron / Q000032:analysis / Q000378:metabolism; D017737:Macrophages, Peritoneal / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009162:Mycobacterium avium / Q000378:metabolism*; D010588:Phagosomes / Q000737:chemistry* / Q000378:metabolism; D011188:Potassium / Q000032:analysis / Q000378:metabolism; D014376:Tuberculosis / Q000276:immunology*; D015032:Zinc / Q000032:analysis / Q000378:metabolism
chemical_list: D002713:Chlorine; D007501:Iron; D015032:Zinc; D011188:Potassium; D002118:Calcium