Immune and neuroendocrine responses in molluscs: the role of cytokines.

In this paper, we overview the data obtained on the presence of cytokine-like molecules in molluscam hemocytes and on the relationships between mammalian cytokines and molluscan immune-neuroendocrine responses. Only the hemocytes with phagocytic activity show immunoreactivity to the different cytokines tested (IL-1 alpha, IL-1 beta, IL-2, IL-6 and TNF-alpha). Mammalian cytokines are able to affect cell motility, bacterial phagocytosis, induction of nitric oxide synthase and the release of biogenic amines by hemocytes. Moreover, we provide evidence suggesting that the cytokines tested can bind to and compete with CRF for the same membrane hemocyte receptor. Our findings indicate that these molecules are ancestral and have maintained their pleiotropicity, functional redundancy and receptor promiscuity.