Type I interferons (IFN), including IFN-beta (IFNB), activate multiple STAT signaling to drive various biological responses. Another type I IFN, IFN-tau (IFNT), secreted by ruminant embryonic trophoblast cells, has multiple functions with low cytotoxicity. Here, we examined the effects of IFNT on human trophoblast cell functions. First, we performed next-generation sequencing and demonstrated that IFNT-dependent changes in the human Sw.71 trophoblast cell line are partly mediated by proinflammatory as well as IFN signaling. Next, we validated candidate genes, and data confirmed that IFNT stimulated interleukin-6 (IL-6) and IL-8 mRNA expression and secretion. However, human IFNB did not affect IL-6 and IL-8 mRNA expression and secretion. IFNT-induced cytokine secretion was dependent on STAT3 signaling, but not STAT1 signaling. In addition, treatment with IFNT, IL-6, or IL-8 increased cell proliferation, and IFNT also stimulated cell migration in human trophoblast cells. Although IFNT did not affect superoxide dismutase (SOD) 1 mRNA expression, it clearly increased mitochondrial SOD2 mRNA expression, resulting in the acceleration of SOD activity. We demonstrated that in addition to IFN signaling, IFNT also regulated inflammation-related signaling as well as cell proliferation, migration, and redox signaling in human trophoblast cells.
Keywords: cytokine; inflammation; interferon tau; trophoblast cells.