Enhanced survival and differentiation in vitro of different neuronal populations by some interleukins.

Data from the literature demonstrate the existence of a growing family of neuropoietic cytokines; members of this group have structural motifs in common with other members and with neurotrophic factors. In this research we studied the responses elicited in vitro by some of these molecules in two different neuronal populations: murine neuroblastoma N18TG2 and neurons from chicken dorsal root ganglia. Both IL-2 and IL-6 improve the survival of murine neuroblastoma cells in clonal density plating experiments; in addition IL-2 significantly inhibits thymidine incorporation by single cell suspension. The survival of sensory neurons, on the other hand, non-responsive to IL-2 and IL-6, was significantly supported by IL-3, which also stimulates their morphological differentiation, inducing the formation of a well-developed neural net. In conclusion, results reported here confirm the neurotrophic activity of some ILs and provide additional neuronal models for future investigations.