Antigenically-activated avian erythrocytes release cytokine-like factors: a conserved phylogenetic function discovered in fish

Fish erythrocytes (FE) are endowed with the ability to produce cytokine like factors when stimulated with Candida albicans (Ca). In order to evaluate whether similar activities are still conserved in bird erythrocytes (BE), a morphological, cytochemical and immunological evaluation was conducted on peripheral cells in chickens (Gallus gallus). BE form rosettes with monocytes (Mo)-macrophages (MØ), and Mo-MØ according to cytochemical analysis maintain phagocytic functions across the evolution. Finally, Ca-activated BE release in the supernatants cytokine like-factors which enhance Mo-MØ phagocytosis (interferon-γ like activity) and inhibit Mo-MØ migration in agarose (Migration inhibitory factor activity). In conclusion, bird erythrocytes, as non immune cells, are able to participate in the immune response contributing to the host defence