Open AccessCytokine effects on maturation of the phagosomes containing Mycobacteria avium subspecies paratuberculosis in J774 cells
Author(s) -
Hostetter Jesse M,
Steadham Edward M,
Haynes Joseph S,
Bailey Theodore B,
Cheville Norman F
Publication year - 2002
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2002.tb00613.x
Subject(s) - mycobacterium avium subspecies paratuberculosis , phagosome , biology , paratuberculosis , microbiology and biotechnology , cytokine , mycobacterium , immunology , bacteria , virology , phagocytosis , genetics
Mycobacterium avium subspecies paratuberculosis ( M. a. ptb ) is an intracellular pathogen of macrophages. Intracellular survival of several species of pathogenic mycobacteria is dependent on inhibition of maturation of the phagosomes containing these pathogens into functional phagolysosomes. In activated macrophages, however, this capacity is reduced, leading to increased bacterial killing. It is the hypothesis of this study that there is increased acidification and maturation of the phagosome containing M. a. ptb in interferon gamma and lipopolysaccharide (IFN‐γ/LPS) activated macrophages. In activated macrophages colocalization of M. a. ptb with either a marker of acidic compartments (Lysotracker Red) or compartments containing a late phagosome maturation marker lysosome‐associated membrane protein‐1 (Lamp‐1) were evaluated by laser confocal microscopy. Intracellular survival of M. a. ptb in activated macrophages was evaluated directly using differential fluorescent live/dead staining. The results of this study demonstrated increased colocalization of both Lysotracker Red and Lamp‐1 with FITC labeled M. a. ptb , which correlated with decreased survival of M. a. ptb within activated macrophages.