Human astrocytes and cytokines: tumor necrosis factor alpha and interferon gamma do not promote astrocytic proliferation.

Astrocyte cell cultures were established from human fetal brains and exposed to human recombinant tumor necrosis factor alpha (TNF alpha) and human recombinant interferon gamma (IFN gamma), and the proliferative response was assessed by bromodeoxyuridine-immunostaining technique. TNF alpha showed an inhibitory activity, while IFN gamma induced a slight increase in the number of astrocytes undergoing cell division. However, in both experiments differences were not statistically significant. Previous studies have demonstrated that TNF alpha and IFN gamma are potent mitogens for adult astrocytes in both in vivo and in vitro conditions. Our results suggest that in developing brain the immunomodulatory activity of cytokines, TNF alpha and IFN gamma, is different from that observed in adult brain.