A cloned chicken lymphokine homologous to both mammalian IL-2 and IL-15.

摘要: IL-2, cloned in several mammalian species, plays a critical role immune system function. Indirect evidence suggests that IL-2-like molecules also exist lower vertebrates, although none has been cloned. In view of the commercial importance poultry and lack any IL-2 sequence data we undertook to clone chicken molecule. To this end, cDNA library was constructed from activated spleen cells screened for T cell proliferative activity. Three clones single gene were isolated produced protein stimulatory blasts. This had 24 25% amino acid identity 44 46% similarity both bovine IL-15. The homology with IL-15 unexpected, since primate reported have no IL-2. However, genetic distance analysis indicated interleukin is closer than homology. Furthermore, characteristics IL-2s: e.g., expression only by cells, mRNA short 5' region preceding open reading frame, leader sequence. It one characteristic unique IL-15: four conserved cysteines allowing two intrachain disulfide bonds.