Effect of IL-1 and IL-6 on protein phosphorylation in leech central nervous system.

Recently interactions of the immune and nervous systems have generated great interest among investigators. Interleukin 1 (IL-l) and 6 (IL-6) have numerous effects in vertebrate nervous systems besides their role as immune mediators. IL-l is synthesized in phagocytic monocytes as well as in the brain. IL-I acts as a growth factor for astroglia, activates the hypothalamic-pituitary-adrenal axis, and it is released after nerve injury. It has been demonstrated that IL-l induces activation of protein kinases. More recently, primitive IL-l-like activities have been identified in invertebrates. These observations prompted us to study whether IL-l and 6 have any effect on protein phosphorylation in the leech central nervous system. Ganglia have been labeled with 32P, and stimulated with either recombinant IL-lbeta or IL-6. Proteins have been separated by electrophoresis and phosphoproteins detected by autoradiography. We have observed that IL-I and IL-6 are able to modify· the level of some proteins in leech segmental ganglia in a timeand dose- dependent manner. Experiments are in progress to determine the interactions betwee the phosphoproteins modulated by the cytokines and that ones triggered by neurotransmitters involved in short-term learning processes.