title: Molecular cloning and functional characterization of murine toll‑like receptor 8.
abstract: Toll-like receptors (TLRs) are a large family of germ-line encoded pattern recognition receptors (PRRs) that recognize pathogen-associated molecular patterns and evoke the relevant innate immune responses. TLR8 is a member of several endosome nucleic acid-sensing TLRs; however little attention has been paid to murine TLR8 (mTLR8) compared with other endosome nucleic acid-sensing TLRs. In the present study, mTLR8 was cloned using reverse transcription-polymerase chain reaction from murine peripheral blood mononuclear cells and its function in regulating innate immune response was characterized. The open reading frame of mTLR8 consists of 3,099 bps and encodes 1,032 amino acids. It contains typical leucine-rich repeats, a transmembrane domain and a Toll/interleukin-1 receptor domain, and it shares a high level of identity with other mammalian species. The expression of mTLR8 has been widely observed in different tissues, and higher expression levels of mTLR8 have mainly been detected in the heart, spleen and lung. Overexpression of mTLR8 is required for the activation of transcription factor nuclear factor-κB and the production of tumor necrosis factor-α. However, mTLR8 is not able to activate interferon regulatory factor 3 or activator protein 1, nor can it induce interferon-α in HEK293T cells. These results indicate that mTLR8, as an important PRR, is indeed functional and is vital role in the activation of innate immune responses. This study may aid in determining the molecular basis of the interactions between mTLR8 and pathogens.
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, P.R. China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, P.R. China.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: He
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, P.R. China.
authors.forename: Huaijie
authors.initials: H
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, P.R. China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, P.R. China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Zeng
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, P.R. China.
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Fang
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, P.R. China.
authors.forename: Qiwang
authors.initials: Q
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, P.R. China.
authors.forename: Zhizhong
authors.initials: Z
authors.lastname: Jing
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D020869:Gene Expression Profiling; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism; D010802:Phylogeny; D017433:Protein Structure, Secondary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020539:Sequence Analysis, Protein; D051200:Toll-Like Receptor 8 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016328:NF-kappa B; D012333:RNA, Messenger; C552579:TLR8 protein, mouse; D051200:Toll-Like Receptor 8; D014409:Tumor Necrosis Factor-alpha