title: Activation of macrophages and interference with CD4+ T-cell stimulation by Mycobacterium avium subspecies paratuberculosis and Mycobacterium avium subspecies avium.
abstract: Mycobacterium avium subspecies paratuberculosis (M. ptb) and M. avium subspecies avium (M. avium) are closely related but exhibit significant differences in their interaction with the host immune system. The macrophage line, J774, was infected with M. ptb and M. avium and analysed for cytokine production and stimulatory capacity towards antigen-specific CD4+ T cells. Under all conditions J774 cells were activated to produce proinflammatory cytokines. No influence on the expression of major histocompatibility complex (MHC) class II, intracellular adhesion molecule-1 (ICAM-1), B7.1, B7.2 or CD40 was found. However, the antigen-specific stimulatory capacity of J774 cells for a CD4+ T-cell line was significantly inhibited after infection with M. ptb, but not with M. avium. When a T-cell hybridoma expressing a T-cell receptor identical to that of the T-cell line was used, this inhibition was not observed, suggesting that costimulation which is essential for the CD4+ T-cell line is influenced by the pathogenic bacterium M. ptb.
authors.affiliation: Molecular Immunology, GBF, German Research Centre for Biotechnology, Braunschweig, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Zur Lage
authors.forename: Ralph
authors.initials: R
authors.lastname: Goethe
authors.forename: Ayub
authors.initials: A
authors.lastname: Darji
authors.forename: Peter
authors.initials: P
authors.lastname: Valentin-Weigand
authors.forename: Siegfried
authors.initials: S
authors.lastname: Weiss
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000382:microbiology; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology*; D008262:Macrophage Activation / Q000276:immunology*; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D009162:Mycobacterium avium / Q000276:immunology*; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology*; D010283:Paratuberculosis / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014376:Tuberculosis / Q000276:immunology
chemical_list: D016207:Cytokines