title: Recombinant TB9.8 of Mycobacterium bovis Triggers the Production of IL-12 p40 and IL-6 in RAW264.7 Macrophages via Activation of the p38, ERK, and NF-κB Signaling Pathways.
abstract: The TB9.8 of Mycobacterium bovis can induce strong antigen-specific T-cell responses in proliferation assays and IFN-γ assays. However, whether and how TB9.8 activates innate immune cells remain unclear. Therefore, recombinant protein TB9.8 (rTB9.8)-induced proinflammatory cytokine profile by RAW264.7 cells was investigated and the related signaling pathway was studied. Stimulation with rTB9.8 triggered RAW264.7 cells to produce IL-6 and IL-12 p40. In addition, rTB9.8 activated the mitogen-activated protein kinase (MAPK) cascade in RAW264.7 cells by inducing the phosphorylation of extracellular signal-regulated kinase (ERK) and p38 kinase (p38) and also promoted nuclear translocation of phosphorylated p38 and ERK1/2. Furthermore, rTB9.8 activated nuclear factor κB (NF-κB) signaling pathway by inducing p65 translocation into the nucleus and the phosphorylation of IκBα in the cytosol. Blocking assays showed that specific inhibitors of ERK1/2, p38, and IκBα can significantly reduce the expression of IL-6 and IL-12 p40, which demonstrated that rTB9.8-mediated cytokine production is dependent on the activation of these kinases. Thus, this study demonstrates that rTB9.8 can activate RAW264.7 and trigger IL-6 and IL-12 p40 production via the ERK, p38, and NF-κB signaling pathways.
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, 100193, Beijing, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Jia
authors.forename: Shuqing
authors.initials: S
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.forename: Shaohua
authors.initials: S
authors.lastname: Hou
authors.forename: Ting
authors.initials: T
authors.lastname: Xin
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Guo
authors.forename: Weifeng
authors.initials: W
authors.lastname: Yuan
authors.forename: Xintao
authors.initials: X
authors.lastname: Gao
authors.forename: Gaimei
authors.initials: G
authors.lastname: Zhang
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Hongfei
authors.initials: H
authors.lastname: Qu
authors.forename: Hongfei
authors.initials: H
authors.lastname: Zhu
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology; D002460:Cell Line; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020672:I-kappa B Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D053762:Interleukin-12 Subunit p40 / Q000096:biosynthesis*; D015850:Interleukin-6 / Q000096:biosynthesis*; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008264:Macrophages / Q000276:immunology; D051379:Mice; D009163:Mycobacterium bovis / Q000378:metabolism*; D000072000:NF-KappaB Inhibitor alpha; D010766:Phosphorylation; D011994:Recombinant Proteins / Q000494:pharmacology; D051996:Transcription Factor RelA / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D020672:I-kappa B Proteins; D053762:Interleukin-12 Subunit p40; D015850:Interleukin-6; C000606204:NFKBIA protein, human; C000606205:Nfkbia protein, mouse; C498143:RELA protein, human; D011994:Recombinant Proteins; D051996:Transcription Factor RelA; D000072000:NF-KappaB Inhibitor alpha; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases