Functional Characterization Of Chicken Cytokines Homologous To Mammalian Il-15 And Il-2

Full-length cDNA encoding chicken IL-15 was cloned from chicken liver cDNA library and its functional characteristics were compared to chicken IL-2. Both recombinant IL-2 and IL-15 stimulated the growth of T cells and enhanced the activity NK-cells in vitro. Subcutaneous injection of chickens with IL-2 genes increased the percentages of CD3+, CD4+, CD8+, gammadelta T, and alphabeta T lymphocytes. In contrast, injection of chickens with IL-15 gene preferentially enhanced CD3+ T lymphocytes. Collectively, these results indicate that chicken IL-15 and IL-2 represent T cell growth factors and these cytokines enhance host immunity mediated by T and NK cells.