title: Molecular identification and functional characterization of a tumor necrosis factor (TNF) gene in Crassostrea hongkongensis.
abstract: Tumor necrosis factor superfamily (TNFSF) represents a group of multifunctional inflammatory cytokines that have been shown to participate in a variety of pathological and immunological process. However, the functions of these proteins in oyster are still poorly understood. In the present study, an oyster TNF homolog (named ChTNF) was identified from a cDNA library of Crassostrea hongkongensis. The complete cDNA of ChTNF was 2457bp in length containing an open reading frame (ORF) of 1044bp, a 5'-untranslated region (UTR) of 381bp and a 3'-UTR of 1032bp. The deduced ChTNF protein consisted of 347 amino acids with a characteristic transmembrane domain and a typical TNF homology domain (THD). Quantitative real-time PCR analysis revealed that ChTNF was broadly expressed in various oyster tissues and different stages of embryonic development. In addition, transcriptional analysis indicated that ChTNF transcription levels in hemocytes were increased significantly in pathogen challenge groups (Vibrio alginolyticus and Staphylococcus haemolyticus) compared to that in the control. Moreover, in vitro PAMP (lipopolysaccharide and peptidoglycan) treatments showed a stimulatory effect on the expression of ChTNF in the primary cultured hemocytes of C. hongkongensis. Finally, dual-luciferase reporter assays revealed that ChTNF could activate the NF-κB-Luc reporter in a dose-dependent manner in HEK293T cells. Altogether, these findings may provide valuable information regarding oyster TNFs and its role in innate immunity.
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China; Department of Biological and Environmental Engineering, Changsha University, Changsha 410022, China.
authors.forename: Fufa
authors.initials: F
authors.lastname: Qu
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China. Electronic address: zhimingxiang@scsio.ac.cn.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Xiang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors.forename: Yuehuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Qin
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China.
authors.forename: Yingli
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China. Electronic address: carlzyu@scsio.ac.cn.
authors.forename: Ziniu
authors.initials: Z
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D049896:Crassostrea / Q000145:classification / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D018076:DNA, Complementary; D015870:Gene Expression; D054884:Host-Pathogen Interactions / Q000235:genetics; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology; D016328:NF-kappa B / Q000378:metabolism; D009928:Organ Specificity / Q000235:genetics; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D048069:Tumor Necrosis Factors / Q000737:chemistry / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D008070:Lipopolysaccharides; D016328:NF-kappa B; D012333:RNA, Messenger; D048069:Tumor Necrosis Factors
keywords: Crassostrea hongkongensis; Expression analysis; Immune challenge; Molecular characterization; Tumor necrosis factor