title: IL-18 expression in pigs following infection with Mycoplasma hyopneumoniae.
abstract: Little is known about the detail of the immune response during infection of pigs with Mycoplasma hyopneumoniae (Mhp). To further understand this important porcine pathogen, we examined the interleukin-18 (IL- 18) response in experimentally infected piglets. We found that large amounts of IL-18 were produced in the bronchoalveolar lavage fluids (BALF) of pigs experimentally infected with Mhp. However, the concentration of interferon-gamma (IFN-gamma) in the same BALF was negatively correlated with that of IL-18. The antibody response against Mhp was found to be associated with the IL-18 concentration in the BALF. Immunohistochemical staining revealed that both IL-18 and IL-18 receptor alpha chain (IL-18Ralpha) were present in macrophages and plasma cells in the lungs of Mhp-infected pigs. Lung mononuclear cells isolated from pneumonic lesions secreted IL-18 and prostaglandin E(2) (PGE(2)) in vitro, and PGE(2) production was enhanced by stimulation with IL-18. These results indicate that IL-18 produced in the pig lung contributes to the development of innate and acquired immune responses against Mhp as a proinflammatory cytokine rather than as an IFN-gamma-inducing factor and may be involved in immunomodulation in pigs.
authors.affiliation: Department of Immunology, National Institute of Animal Health, Tsukuba, Ibaraki, 305-0856, Japan. ymuneta@affrc.go.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Muneta
authors.forename: Yu
authors.initials: Y
authors.lastname: Minagawa
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Shimoji
authors.forename: Reiko
authors.initials: R
authors.lastname: Nagata
authors.forename: Philip F
authors.initials: PF
authors.lastname: Markham
authors.forename: Glenn F
authors.initials: GF
authors.lastname: Browning
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Mori
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D015232:Dinoprostone / Q000276:immunology; D005260:Female; D007113:Immunity, Innate / Q000502:physiology; D007371:Interferon-gamma / Q000378:metabolism; D020382:Interleukin-18 / Q000378:metabolism*; D008168:Lung / Q000166:cytology / Q000276:immunology / Q000382:microbiology; D008264:Macrophages / Q000276:immunology; D045705:Mycoplasma hyopneumoniae / Q000276:immunology* / Q000472:pathogenicity; D010950:Plasma Cells / Q000276:immunology; D045729:Pneumonia of Swine, Mycoplasmal / Q000276:immunology*; D053724:Receptors, Interleukin-18 / Q000378:metabolism; D013552:Swine / Q000276:immunology / Q000382:microbiology
chemical_list: D020382:Interleukin-18; D053724:Receptors, Interleukin-18; D007371:Interferon-gamma; D015232:Dinoprostone