title: Mycoplasma pneumoniae extract induces an IL-17-associated inflammatory reaction in murine lung: implication for mycoplasmal pneumonia.
abstract: Mycoplasma pneumoniae (Mp) may cause immune cell reactions as pivotal aspects of this clinically common respiratory pathogen. Our aim is to determine if Mp extract induces a cellular immune response associated with interleukin (IL)-17, leading to lung inflammation and lung injury. BALB/c mice were immunized with Mp extract intraperitoneally followed by its intratracheal administration, to mimic repeated Mp infection found in humans (repeated inoculation, RI group). Those with a single inoculation were compared as single inoculation group (SI group). Analysis of bronchoalveolar lavage fluid (BALF) demonstrated that keratinocyte-derived cytokine, tumor necrosis factor-α, and IL-6 were produced and peaked on days 0.5 or 1, followed by IL-17 on day 2. Levels of these mediators in BALF were higher in RI group than SI group (P < 0.05). Further, significantly more neutrophils were recruited to the lungs of the RI group (P < 0.05). These observations suggest that IL-17 is involved in the prolonged induction of neutrophils in mice treated with Mp extract.
authors.affiliation: Department of Respiratory Medicine, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka-shi, Tokyo, 181-8611, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kurai
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Nakagaki
authors.forename: Hiroo
authors.initials: H
authors.lastname: Wada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Saraya
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kamiya
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Fujioka
authors.forename: Koh
authors.initials: K
authors.lastname: Nakata
authors.forename: Hajime
authors.initials: H
authors.lastname: Takizawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Goto
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D002478:Cells, Cultured; D005260:Female; D007114:Immunization; D007249:Inflammation; D020381:Interleukin-17 / Q000096:biosynthesis / Q000276:immunology*; D053759:Interleukin-23 / Q000378:metabolism; D015850:Interleukin-6 / Q000096:biosynthesis / Q000276:immunology; D008168:Lung / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D009177:Mycoplasma pneumoniae / Q000276:immunology* / Q000378:metabolism; D009504:Neutrophils / Q000276:immunology; D011019:Pneumonia, Mycoplasma / Q000276:immunology* / Q000382:microbiology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000276:immunology
chemical_list: D020381:Interleukin-17; D053759:Interleukin-23; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha