title: Molecular cloning and characterization of chicken lipopolysaccharide-induced TNF-alpha factor (LITAF).
abstract: The inflammatory response to parasites, bacteria, and viruses is mediated by multiple host factors. TNF-alpha is one of the most pleiotropic cytokines in mammals, but has yet to be identified in avian species. In the current study, we isolated a full-length cDNA encoding the chicken homologue of LPS-induced TNF-alpha factor (LITAF), transcription factor, with an open reading frame of 148 amino acids and a predicted molecular mass of 16.0kDa. Quantitative RT-PCR analysis showed that chicken LITAF mRNA was predominantly expressed in spleen and intestinal intraepithelial lymphocytes (IELs). LITAF mRNA levels were up-regulated following in vitro stimulation of macrophages for 4 h with Escherichia coli or Salmonella typhimurium endotoxin, and 18-48 h after treatment with Eimeria acervulina, E. maxima, or E. tenella, three causative agents of avian coccidiosis. LITAF mRNA was up-regulated by more than 700-fold in IELs isolated from E. maxima-infected birds. Purified recombinant LITAF protein expressed in E. coli or COS7 cells exhibited cytotoxic activity against chicken tumor cell lines in vitro, presumably through autocrine activation of TNF-alpha or its chicken homologue. This supposition was strengthened by the fact that treatment of chicken macrophages with recombinant LITAF induced the expression of TL1A (TNFSF 15), a member of the TNF ligand super family. We conclude that chicken LITAF may play an important role in the regulation of TNF-alpha gene expression during the course of coccidiosis or tumorigenesis.
authors.affiliation: Animal Parasitic Diseases Laboratory, Animal and Natural Resources Institute, United States Department of Agriculture, Beltsville, MD 20705, USA.
authors.forename: Yeong Ho
authors.initials: YH
authors.lastname: Hong
authors.forename: Hyun S
authors.initials: HS
authors.lastname: Lillehoj
authors.forename: Sung Hyen
authors.initials: SH
authors.lastname: Lee
authors.forename: Dong  Woon
authors.initials: D
authors.lastname: Park
authors.forename: Erik P
authors.initials: EP
authors.lastname: Lillehoj
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D002645:Chickens / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D003048:Coccidiosis / Q000378:metabolism; D018076:DNA, Complementary; D004539:Eimeria / Q000502:physiology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D014409:Tumor Necrosis Factor-alpha / Q000737:chemistry / Q000235:genetics
chemical_list: D030161:Avian Proteins; D018076:DNA, Complementary; C118738:LITAF protein, human; D008070:Lipopolysaccharides; D009687:Nuclear Proteins; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha