Lipopolysaccharide-induced innate immune factors in the bottlenose dolphin (Tursiops truncatus) detected in expression sequence tag analysis

ABSTRACT EST analysis based on the megaclone‐megasorting method was performed using leukocytes from the bottlenose dolphin (Tursiops truncatus) with or without LPS stimulation. A total of 849 upregulated and 384 downregulated EST clones were sequenced, annotated, and functionally classified. Ferritin heavy peptide I was the most abundant upregulated transcript, suggesting that LPS stimulation induced high production of reactive oxygen species, which were sequestered in ferritin. Among the immune factors, the transcripts coding for an IL‐1Ra, homologs to bovine serum amyloid A3, and canine intercellular adhesion molecule‐1 were highly expressed. Markedly downregulated transcripts of immune factors were those for homologs of calcium‐binding proteins belonging to the S100 family, S100A12, S100A8, and S100A6. Time‐course experiments on the expression of some immune factors including IL‐1Ra suggested that these factors interact and control cetacean innate immunity.