title: Intracellular pathogens and antigen presentation-new challenges with Legionella pneumophila.
abstract: In this issue of Immunity, examine the intracellular life of Legionella pneumophila in dendritic cells (DC) and macrophages, as well as the presentation of its antigens to CD4 T cells. Legionella is a particularly interesting bacterium because of the peculiarities inherent in its intracellular sojourn in phagocytes: it resides in an unusual vesicle characterized by ribosomes studded along its walls. In this compartment, Legionella proteins encoded by the dot gene inhibit phagosome-lysosome fusion and endosomal acidification, yielding a vesicular structure conducive to the multiplication of Legionella, poor in lysosomal contents, and in MHC molecules.
authors.affiliation: Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: Emil R
authors.initials: ER
authors.lastname: Unanue
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology*; D007371:Interferon-gamma / Q000378:metabolism; D016952:Legionella pneumophila / Q000276:immunology* / Q000472:pathogenicity; D007877:Legionnaires' Disease / Q000276:immunology; D051379:Mice
chemical_list: D007371:Interferon-gamma