The objective of this study was to determine the role of proinflammatory cytokines in the induction of acute phase proteins in primary cultured bovine hepatocytes. Among the cytokines examined, bovine interleukin-6 (boIL-6), a product of a baculovirus expression system, decreased the production of albumin (Alb), a negative acute phase protein, in primary cultured bovine hepatocytes. Interleukin-1β (boIL-1β), tumor necrosis factor-α (boTNF-α) and interferon-γ (boIFN-γ) also affected the cells to decrease Alb production. The synthesis of haptoglobin (Hp), a positive acute phase protein, was stimulated by boIL-6, boIL-1β and boTNF-α, but not by boIFN-γ. Among those cytokines, IL-6 was the most effective inducer of Hp synthesis. To estimate the additive or synergistic effects among cytokines, we further investigated the effects of boIL-1β, boTNF-α or boIFN-γ combined with boIL-6 on the Hp secretion of hepatocytes. BoTNF-α enhanced IL-6 induced Hp secretion, whereas IFN-γ inhibited the secretion. BoIFN-γ showed no synergism with boIL-6. (Safety Evaluation Section, Department of Safety Research TEL +81-298-38-7824)
References:
Yoshioka, M., et al.: Biological functions of recombinant bovine interleukin 6 expressed in a baculovirus system. Cytokine, 11:863-868 (1999)
