Innate immune responses of pulmonary epithelial cells to Burkholderia pseudomallei infection

• Published in: PloS one Vol. 4; no. 10; p. e7308
• Main Authors: Sim, Siew Hoon, Liu, Yichun, Wang, Dongling, Novem, Vidhya, Sivalingam, Suppiah Paramalingam, Thong, Tuck Weng, Ooi, Eng Eong, Tan, Gladys
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06.10.2009; Public Library of Science (PLoS)
• Subjects: Aerosols; Analysis; Animals; Antimicrobial peptides; Bacteria; Burkholderia Infections - immunology; Burkholderia Infections - metabolism; Burkholderia pseudomallei; Burkholderia pseudomallei - metabolism; CCL20 protein; Cell Line; Chemokine CCL2 - metabolism; Chemokines; Cytokines; Disseminated infection; Epithelial cells; Epithelial Cells - immunology; Epithelial Cells - microbiology; Female; Gene expression; Growth factors; Health aspects; Helicobacter pylori; Immune response; Immune system; Immunity; Immunity, Innate; Immunology; Immunology/Immune Response; Immunology/Immunity to Infections; Immunology/Innate Immunity; Infection; Infections; Infectious Diseases/Bacterial Infections; Infectious Diseases/Respiratory Infections; Inflammation; Innate immunity; Interleukin 6; Interleukin-6 - metabolism; Kinases; Laboratories; Lung - immunology; Lung - microbiology; Lungs; Lymphocytes B; MAP kinase; Medical research; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Monocyte chemoattractant protein 1; NF-κB protein; Peptides; Pneumonia; Protease inhibitors; Proteases; Proteins; Shigella; Transgenic animals; Tumor Necrosis Factor-alpha - metabolism; Tumor necrosis factor-TNF; Tumor necrosis factor-α; Wind; Australia; Singapore
• DOI: 10.1371/journal.pone.0007308
• ISSN: 1932-6203

Burkholderia pseudomallei, a facultative intracellular pathogen, causes systemic infection in humans with high mortality especially when infection occurs through an infectious aerosol. Previous studies indicated that the epithelial cells in the lung are an active participant in host immunity. In this study, we aimed to investigate the innate immune responses of lung epithelial cells against B. pseudomallei. Using a murine lung epithelial cell line, primary lung epithelial cells and an inhalational murine infection model, we characterized the types of innate immunity proteins and peptides produced upon B. pseudomallei infection. Among a wide panel of immune components studied, increased levels of major pro-inflammatory cytokines IL-6 and TNFalpha, chemokine MCP-1, and up-regulation of secretory leukocyte protease inhibitor (SLPI) and chemokine (C-C motif) ligand 20 (CCL20) were observed. Inhibition assays using specific inhibitors suggested that NF-kappaB and p38 MAPK pathways were responsible for these B. pseudomallei-induced antimicrobial peptides. Our findings indicate that the respiratory epithelial cells, which form the majority of the cells lining the epithelial tract and the lung, have important roles in the innate immune response against B. pseudomallei infection.