Expression of cytokines in human thyroid primary cells in culture incubated with recombinant HCV envelope protein E2. Recombinant HCV E2 protein at a concentration of 5 µg/mL induced an increased expression of IL-6, IL-8, and TNFα both at the mRNA and at the protein levels. Time course up to 1 week shows increased protein secretion in supernatants of human primary thyrocytes. (A–C) Relative expression of mRNA by real-time qPCR (corrected to glyceraldehyde 3-phosphate dehydrogenase): (A) IL-6, (B) IL-8, and (C) TNFα. (D–F) Concentration of cytokines (pg/mL) in supernatant: (D) IL-6, (E) IL-8, and (F) TNFα. Results are presented as mean ± standard error of the mean. *P < 0.05; **P < 0.01; ***P < 0.001.