Molecular Characterization of Pro-Inflammatory Cytokines Interleukin-1 beta and Interleukin-8 in Asian Elephant (Elephas maximus)

摘要

Interleukin (IL)-1 beta and IL-8 are pro-inflammatory cytokines produced primarily by monocytes and macrophages in response to a variety of microbial and nonmicrobial agents. As yet, no molecular data have been reported for IL-1 beta and IL-8 of the Asian elephant. In the present study, we have cloned and sequenced the cDNA encoding IL-1 beta and IL-8 of the Asian elephant. The open reading frame (ORF) of Asian elephant IL-1 beta is 789 bp in length, encoded a propeptide of 263 amino acid polypeptide. The predicted protein revealed the presence of IL-1 family signature motif and an ICE cut site. Whereas, IL-8 contained 321 bp of open reading frame. Interestingly, the predicted protein sequence of 106 aa, contains an ELR motif immediately upstream of the CQC residues, common in all vertebrate IL-8 molecules. Identity levels of the nucleic acid and deduced amino acid sequences of Asian elephant IL-1 beta ranged from 68.48 (Squirrel monkey) to 98.57% (African elephant), and 57.78 (Sheep) to 98.47% (African elephant), respectively, whereas that of IL-8 ranged from 72.9% (Human) to 87.8% (African elephant), and 63.2 (human, gorilla, chimpanzee) to 74.5% (African elephant, buffalo), respectively. The phylogenetic analysis based on deduced amino acid sequenced showed that the Asian elephant IL-1 beta and IL-8 were most closely related to African elephant. Molecular characterization of these two cytokines, IL-1 beta and IL-8, in Asian elephant provides fundamental information necessary to progress the study of functional immune responses in this animal and gives the potential to use them to manipulate the immune response as recombinant proteins.