Toll-like receptor 3 (TLR3) upregulation by interferon α (IFNα). Dermal fibroblasts from healthy control skin were cultured in vitro with IFNα (50-150 ng/mL) or 0.1% bovine serum albumin (BSA) for 6, 24 and 48 hours. Total RNA was harvested, and (A) TLR3 and (B) TLR4 mRNA levels were determined by performing quantitative real-time polymerase chain reaction (qRT-PCR) assays. IFN induced TLR3 upregulation at 6, 24 and 48 hours. TLR4 upregulation was noted only at 6 hours. (C) Dose-response curve for TLR3 upregulation by IFNα (0-100 ng/mL) for 24 hours in healthy control dermal fibroblasts. n = 3 control cell lines.