Schneider, Kirsten; Puehler, Florian; Baeuerle, Daniela; Elvers, Sandra; Staeheli, Peter; Kaspers, Bernd; Weining, Kirsten C.
cDNA Cloning of Biologically Active Chicken Interleukin-18.
In: Journal of Interferon & Cytokine Research, Vol. 20, No. 10: pp. 879-883
By searching a chicken EST database, we identified a cDNA clone that appeared to contain the entire open
reading frame (ORF) of chicken interleukin-18 (ChIL-18). The encoded protein consists of 198 amino acids
and exhibits approximately 30% sequence identity to IL-18 of humans and various others mammals. Sequence
comparisons reveals a putative caspase-1 cleavage site at aspartic acid 29 of the primary translation product,
indicating that mature ChIL-18 might consist of 169 amino acids. Bacterially expressed ChIL-18 in which the
N-terminal 29 amino acids of the putative precursor molecule were replaced by a histidine tag induced the
synthesis of interferon-γ (IFN-γ) in cultured primary chicken spleen cells, indicating that the recombinant
protein is biologically active.