01681nas a2200289   4500000000100000008004100001260001300042653002100055653001200076653002800088653001200116653001400128653001600142653002000158653000900178653002500187653002500212653001500237653002300252100001300275700001400288245011100302300001200413490000700425520094500432022001401377       1987                            d  c1987 Dec10aAcid Phosphatase10aAnimals10aIntracellular Membranes10aleprosy10aLysosomes10aMacrophages10aMembrane Fusion10aMice10aMicroscopy, Electron10aMycobacterium leprae10aPhagosomes10aSurface Properties1 aFrehel C1 aRastogi N00aMycobacterium leprae surface components intervene in the early phagosome-lysosome fusion inhibition event.  a2916-210 v553 a<p>Bone marrow-derived cultured macrophages were infected with Mycobacterium leprae. The bacteria were either used as freshly isolated organisms or incubated with M. leprae antiserum (1:5) for 30 min prior to phagocytosis. Immediately after inoculation (1 to 4 h) and at 1 to 8 days later, macrophages were stained for acid phosphatase activity to assess fusions between phagosomes and lysosomes. Inhibition of fusions was essentially apparent as an early event, which was partially reversed by antiserum treatment of the bacteria, suggesting a role for M. leprae immunogenic surface components in this early phenomenon. Later incubation times (1 to 8 days) did not show any considerable difference between antiserum-treated and nontreated bacteria. The formation of an electron-transparent zone around phagocytized bacteria and its role in phagosome-lysosome fusion was investigated, and a direct relationship could not be established.</p>  a0019-9567