title: Strains of Mycobacterium avium differentially activate human dendritic cells.
abstract: Animal models indicate that exposure to environmental strains of mycobacteria can modulate immune responses and influence the effectiveness of live mycobacterial vaccines. Here, we describe that between the two recently reported Mycobacterium avium isolates, strain WAg 206 (but not strain WAg 207) interferes with human monocyte-derived dendritic cell (MDDC) activation. WAg 206, unlike WAg 207, did not elicit inflammatory cytokine production (TNFalpha, IL-1beta, IL-12) or costimulatory molecule expression (HLA-DR, CD83, CD80, CD86) by human MDDCs in vitro. These data highlight the potential for environmental mycobacteria to modulate immune responses in humans, and suggest a mechanism by which earlier exposure to such microbes may compromise the efficacy of live mycobacterial vaccines, as has been observed in some human BCG vaccine trials.
authors: Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
authors: Glenn S
authors: GS
authors: Buchan
authors: Rachel
authors: R
authors: Lee
authors: Michelle
authors: M
authors: Wilson
authors: Lynn
authors: L
authors: Slobbe
authors: Bryce M
authors: BM
authors: Buddle
authors: Sarah L
authors: SL
authors: Young
mesh_terms: D015703:Antigens, CD / Q000276:immunology; D002454:Cell Differentiation; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D009000:Monocytes / Q000166:cytology / Q000276:immunology; D009162:Mycobacterium avium / Q000254:growth & development / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D016207:Cytokines; D006680:HLA Antigens