Mycobacterium bovisBCG Vaccination Augments Interleukin-8 mRNA Expression and Protein Production in Guinea Pig Alveolar Macrophages Infected withMycobacterium tuberculosis

Open Access
Publisher Website
Google Scholar
Abstract
Alveolar macrophages are likely the first cell type to encounterMycobacterium tuberculosisin a pulmonary infection, resulting in the production of chemokines. In order to evaluate this response, alveolar macrophages harvested from nonvaccinated andMycobacterium bovisBCG-vaccinated guinea pigs were infected in vitro with liveM. tuberculosisH37Ra or H37Rv (multiplicity of infection, 1:1) or cultured with lipopolysaccharide (10 μg/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 attenuatedM. 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 theM. tuberculosis-infected lung.

This publication has 70 references indexed in Scilit: