title: Increased intracellular growth of Mycobacterium avium in HIV-1 exposed monocyte-derived dendritic cells.
abstract: Dendritic cells (DC) are the most potent antigen-presenting cells, and form a link between the innate and adaptive immune system. They sample the periphery of the body for antigens and present them to T cells to elicit a proper immune response. It has been shown that dendritic cells phagocytose mycobacteria, but there have been conflicting reports as to whether the bacteria are capable of intracellular replication in DCs. Mycobacterium avium is a facultative intracellular bacterium, part of the Mycobacterium avium complex (MAC) of mycobacteria and are commonly seen as opportunistic pathogens in patients infected by Human immunodeficiency virus type 1 (HIV-1). To clarify the issue of whether DCs are capable of controlling the intracellular growth of M. avium and whether this control is lost upon HIV-1 exposure, we investigated the intracellular replication of M. avium in monocyte-derived dendritic cells and compared it to bacterial growth in dendritic cultures exposed to HIV-1 for 24 h. Our results show that exposure of DCs to HIV-1 promotes or facilitates the intracellular growth of M. avium.
authors.affiliation: Section for Microbiology and Immunology, The Gade Institute, University of Bergen, Laboratory Building, 5th floor, Haukeland University Hospital, N-5021 Bergen, Norway.
authors.forename: Tore
authors.initials: T
authors.lastname: Salte
authors.forename: Sharad
authors.initials: S
authors.lastname: Pathak
authors.forename: Tore
authors.initials: T
authors.lastname: Wentzel-Larsen
authors.forename: Birgitta
authors.initials: B
authors.lastname: Asjö
mesh_terms: D048708:Cell Growth Processes / Q000502:physiology; D015169:Colony Count, Microbial; D003713:Dendritic Cells / Q000382:microbiology* / Q000821:virology; D005434:Flow Cytometry; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D042541:Intracellular Space / Q000382:microbiology / Q000821:virology; D009162:Mycobacterium avium / Q000254:growth & development*; D010587:Phagocytosis; D016133:Polymerase Chain Reaction; D051195:Toll-Like Receptor 2 / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014771:Virion / Q000502:physiology
chemical_list: C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha