Expression of Interleukin-2 Receptor in Primary Cultured Adult Human Astrocytes

Background : Astrocytes are the major glial cells involved with the chemical homeostasis and mechanical supports of central nervous system. Recently, astrocytes were found to actively synthesize and secrete many immunologically active cytokines and express receptors for these mediators, which proposed their autocrine and paracrine roles in the pathogenesis of many neurodegenerative or autoimmune diseases, i.e., multiple sclerosis, Alzheimer`s disease, etc. The identification of various chemical mediators secreted by astrocytes and receptors expressed on astrocytes seems to be crucial for understanding their pathogenetic roles in these diseases. Our investigation was conducted to test the expression of interleukin-2 receptor α subunit (IL-2Rα) on primary cultured astrocytes, which has not been studied yet. Methods : Astrocytes were obtained from the surgical specimen of a patient with intractable temporal lobe epilepsy. Neuropathological examination of the specimen revealed hippocampal sclerosis only with normal lateral temporal neocortex from which cultured astrocytes were obtained. All experiments were performed within 2 months after starting primary culture. Cultured astroyctes were incubated with IL-1, IL-2, IL-6, TGF-βand TNF-α for 24 hours. RT-PCR was performed to investigate the transcription of IL-2R. Results : RT-PCRs for the IL-2Rα showed constitutional expression on the adult cultured astrocytes, which was IL-1, IL-2, IL-6, and TNF-α but decreased by treatment of TGF-β. Conclusions : Adult astrocytes expressed IL-2Rα constitutively, which were upregulated by IL-1, IL-2, IL-6 and TNF-α. These findings suggest the immunocompetence of astrocytes, which may be important in the pathogenesis of many neurological diseases.ope