title: Apoptosis are induced in J774 macrophages upon phagocytosis and killing of Pseudomonas aeruginosa.
abstract: Apoptosis induced by Pseudomonas aeruginosa in host cells plays a role in pathogenesis. However, little is known how the apoptosis of macrophages harboring P. aeruginosa affects the host or pathogen. In this study, the viability of J774 macrophages phagocytosing Pa IID1117 (elastase- and protease-positive) was significantly reduced (53.8±4.5%) 48 h after infection and cell death occurred via apoptosis as seen by Hoechst 33258 staining and terminal deoxynucleotidyl transferase-mediated d-UTP nick end labeling (TUNEL) assay. An activated subunit of caspase 3 was found in the cellular lysate. Lower colony counts in infected cells and effective intracellular killing of bacteria were accompanied by enhanced apoptosis. Caspase 3 inhibiter inhibited apoptosis but did not prevent cell death and the extracellular leakage of bacteria. The apoptosis of the macrophages that phagocytose P. aeruginosa therefore inhibits the intracellular growth and spread of this bacterium and is important in host defense against P. aeruginosa infections.
authors.affiliation: Department of Immunology and Pathogenic Biology, Tianjin University of Traditional Chinese Medicine, 312 West Anshan Road, Nankai District, Tianjin 300193, China; Department of Microbiology and Pathology, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan. Electronic address: jianlingzhang@tjutcm.edu.cn.
authors.forename: Jianling
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA.
authors.forename: Ru
authors.initials: R
authors.lastname: Jiang
authors.affiliation: Department of Biochemistry, Tianjin University of Traditional Chinese Medicine, 312 West Anshan Road, Nankai District, Tianjin 300193, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Microbiology and Pathology, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan.
authors.forename: Hisao
authors.initials: H
authors.lastname: Takayama
authors.affiliation: Department of Microbiology and Pathology, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D053148:Caspase 3 / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D015169:Colony Count, Microbial; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D015870:Gene Expression; D054884:Host-Pathogen Interactions; D020287:In Situ Nick-End Labeling; D008264:Macrophages / Q000187:drug effects / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D009842:Oligopeptides / Q000494:pharmacology; D010196:Pancreatic Elastase / Q000235:genetics / Q000378:metabolism; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects*; D011550:Pseudomonas aeruginosa / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D015853:Cysteine Proteinase Inhibitors; D009842:Oligopeptides; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; D010447:Peptide Hydrolases; D010196:Pancreatic Elastase; D053148:Caspase 3
keywords: Apoptosis; CFU; Caspase 3; DMEM; Dulbecco’s Modified Eagle’s medium; FCS; LDH; MOI; Macrophage; P. aeruginosa; PBS; Pa; Phagocytosis; Pseudomonas aeruginosa; SDS–PAGE; TUNEL; colony-forming unit; fetal calf serum; lactate dehydrogenase; multiplicity of infection; phosphate-buffered saline; sodium dodecyl sulfate–polymerase chain reaction; terminal deoxynucleotidyl transferase-mediated d-UTP-biotin nick end labeling