Th17 master transcription factors RORα and RORγ regulate the expression of IL-17C, IL-17D and IL-17F in Cynoglossus semilaevis

• CsRORα and CsRORγ expression was regulated by bacterial and viral infection.
• CsRORα and CsRORγ proteins were detected in nucleus.
• CsRORα increased the expression of CsIL-17C, CsIL-17D, and CsIL-17F.
• CsRORγ increased the expression of CsIL-17C and CsIL-17F.

The RAR-related orphan receptors (RORs) are members of the nuclear receptor family of intracellular transcription factors. In this study, we examined the regulatory properties of RORα (CsRORα) and RORγ (CsRORγ) in tongue sole (Cynoglossus semilaevis). CsRORα and CsRORγ expression was detected in major lymphoid organs and altered to significant extents after bacterial and viral infection. CsRORα enhanced the activities of CsIL-17C, CsIL-17D, and CsIL-17F promoters, which contain CsRORα and CsRORγ binding sites. CsRORγ also upregulated the promoter activities of CsIL-17D and CsIL-17F but not CsIL-17C. CsRORα and CsRORγ proteins were detected in the nucleus, and overexpression of CsRORα in tongue sole significantly increased the expression of CsIL-17C, CsIL-17D, and CsIL-17F, whereas overexpression of CsRORγ significantly increased the expression of CsIL-17C and CsIL-17F but no CsIL-17D. These results indicate that RORα and RORγ in teleost regulate the expression of IL-17 members in different manners.