Effect of Type I Interferon(s) on Cell Viability and Apoptosis in Primary Human Thyrocyte Cultures

Background: Interferon (IFN) therapy may induce a generalized activation of the immune system, hence triggering or exacerbating autoimmune disease. Apoptosis contributes to the development of hypothyroidism in autoimmune thyroiditis. IFN can affect all phases of the cell cycle and may induce apoptosis in several cell lines from varied histologies. To date, no data exist on the possible effect of type I IFN(s) on FAS/FASL system and cell apoptosis of human thyroid follicles. Therefore, we evaluated the effect of both IFN-α and -β on apoptosis in primary human thyrocyte cultures and the potential role of the FAS/FASL pathway. Methods: Thyrocytes were cultured in monolayers and FAS, FASL, and Bcl-2 mRNA expression was determined by reverse transcriptase polymerase chain reaction after exposure to 10 mIU/mL bovine thyroid-stimulating hormone alone or in combination with increasing doses of IFN-α or -β for 24, 48, and 72 hours. The percentage of apoptotic hypodiploid cells was evaluated by flow cytometry. Resu...