Molecular cloning and characterization of chicken lipopolysaccharide-induced TNF-alpha factor (LITAF).
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.
Hong
Yeong Ho
YH
Animal Parasitic Diseases Laboratory, Animal and Natural Resources Institute, United States Department of Agriculture, Beltsville, MD 20705, USA.
Lillehoj
Hyun S
HS
Lee
Sung Hyen
SH
Park
Dong  Woon
D
Lillehoj
Erik P
EP
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
D030161:Avian Proteins; D018076:DNA, Complementary; C118738:LITAF protein, human; D008070:Lipopolysaccharides; D009687:Nuclear Proteins; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha