title: Mycoplasma bovis escapes bovine neutrophil extracellular traps.
abstract: Mycoplasma bovis is a significant pathogen in bovine infections including mastitis, pneumonia, arthritis and otitis media, and is the cause of large economic losses in beef and dairy farms. During infection with M. bovis, recruited neutrophils are not sufficient to eradicate M. bovis from the infection site. The release of neutrophil extracellular traps (NETs) is one of the innate immune responses of neutrophils but the effect of M. bovis on NET formation by bovine neutrophils has not yet been clarified. The objective of our research was to examine the effect of M. bovis on NET formation and the killing activity of bovine neutrophils. We showed that NETs were not detected following stimulation of neutrophils by M. bovis alone or with Phorbol 12-myristate 13-acetat (PMA). Reactive oxygen species production is essential for NET formation but the levels in neutrophils stimulated with M. bovis at multiplicity of infections of 10, 100, and 1000 were similar to those of unstimulated cells. NET formation induced by PMA stimulated neutrophils disappeared following the addition of M. bovis but this phenomenon was not observed when ethylenediaminetetraacetic acid (EDTA) was added. M. bovis colony forming units were significantly decreased by the addition of EDTA in the presence of NETs. Our results suggested that M. bovis infection alone did not induce NETs and that M. bovis nucleases, as hypothesis-based, contributed to resistance against the killing activity of NETs.
authors.affiliation: Animal Health Laboratory, Graduate School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan. Electronic address: s21241002@g.rakuno.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Gondaira
authors.affiliation: Animal Health Laboratory, Graduate School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan. Electronic address: higuchi@rakuno.ac.jp.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Higuchi
authors.affiliation: Animal Health Laboratory, Graduate School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan. Electronic address: s21161130@stu.rakuno.ac.jp.
authors.forename: Koji
authors.initials: K
authors.lastname: Nishi
authors.affiliation: Department of Veterinary Biochemistry, Graduate School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan. Electronic address: h-iwano@rakuno.ac.jp.
authors.forename: Hidetomo
authors.initials: H
authors.lastname: Iwano
authors.affiliation: Animal Health Laboratory, Graduate School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan. Electronic address: nagahata@rakuno.ac.jp.
authors.forename: Hajime
authors.initials: H
authors.lastname: Nagahata
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D065096:Calcium Chelating Agents / Q000494:pharmacology; D002417:Cattle; D002478:Cells, Cultured; D003851:Deoxyribonucleases / Q000378:metabolism; D004492:Edetic Acid / Q000494:pharmacology; D065206:Extracellular Traps / Q000187:drug effects / Q000382:microbiology*; D005260:Female; D007113:Immunity, Innate / Q000187:drug effects / Q000276:immunology*; D009175:Mycoplasma Infections / Q000201:enzymology / Q000276:immunology / Q000662:veterinary*; D045682:Mycoplasma bovis / Q000201:enzymology / Q000276:immunology*; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology* / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D065096:Calcium Chelating Agents; D004492:Edetic Acid; D003851:Deoxyribonucleases
keywords: Bovine neutrophils; Mycoplasma bovis; Neutrophil extracellular traps; Nuclease; Pathogenic factor