title: Mycobacterium bovis BCG vaccination augments interleukin-8 mRNA expression and protein production in guinea pig alveolar macrophages infected with Mycobacterium tuberculosis.
abstract: Alveolar macrophages are likely the first cell type to encounter Mycobacterium tuberculosis in a pulmonary infection, resulting in the production of chemokines. In order to evaluate this response, alveolar macrophages harvested from nonvaccinated and Mycobacterium bovis BCG-vaccinated guinea pigs were infected in vitro with live M. tuberculosis H37Ra or H37Rv (multiplicity of infection, 1:1) or cultured with lipopolysaccharide (10 micro g/ml) for 3, 12, and 24 h. Interleukin-8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1) mRNA expression was determined by real-time PCR. Culture supernatants were assayed for guinea pig IL-8 protein by using a human IL-8 enzyme-linked immunosorbent assay kit. Alveolar macrophages harvested from BCG-vaccinated guinea pigs produced significantly more mRNA and protein for IL-8 than alveolar macrophages harvested from nonvaccinated guinea pigs at 12 and 24 h poststimulation or postinfection. Infection with attenuated M. tuberculosis (H37Ra) stimulated alveolar macrophages isolated from BCG-vaccinated guinea pigs to produce significantly more IL-8 mRNA than did alveolar macrophages infected with a virulent strain (H37Rv) at 12 and 24 h postinfection. Significant MCP-1 mRNA production was also detected in stimulated or infected alveolar macrophages; however, prior vaccination did not significantly affect levels of MCP-1 mRNA. Alveolar macrophages isolated from BCG-vaccinated guinea pigs produced significantly more IL-8 mRNA and protein when stimulated for 24 h with heat-killed H37Ra, heat-killed H37Rv, and H37Rv cell wall, but not mannose-capped lipoarabinomannan (ManLAM), than did cells stimulated with media alone. These observations indicate that prior vaccination may alter very early events in the M. tuberculosis-infected lung.
authors.affiliation: Department of Medical Microbiology and Immunology, Texas A&M University System Health Science Center, College Station, Texas 77843, USA.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Lyons
authors.forename: Teizo
authors.initials: T
authors.lastname: Yoshimura
authors.forename: David N
authors.initials: DN
authors.lastname: McMurray
mesh_terms: D000818:Animals; D001500:BCG Vaccine / Q000494:pharmacology*; D018932:Chemokine CCL2 / Q000235:genetics; D004195:Disease Models, Animal; D015870:Gene Expression; D006168:Guinea Pigs; D066298:In Vitro Techniques; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics*; D008070:Lipopolysaccharides / Q000494:pharmacology; D016676:Macrophages, Alveolar / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*; D009169:Mycobacterium tuberculosis / Q000472:pathogenicity*; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D014397:Tuberculosis, Pulmonary / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000517:prevention & control; D014774:Virulence
chemical_list: D001500:BCG Vaccine; D018932:Chemokine CCL2; D016209:Interleukin-8; D008070:Lipopolysaccharides; D012333:RNA, Messenger; C050016:lipoarabinomannan