Molecular characterization of the receptor subunits of IL-10 in a perciform fish, Nibea albiflora.

The transmembrane receptor complex of Interleukin-10 (IL-10), comprising the IL-10Rα subunit and IL-10Rβ subunits, belong to the class Ⅱ cytokine receptor family. In the present study, IL-10Rα and IL-10Rβ were characterized in Nibea albiflora (referred to as NaIL-10Rα (MZ620685.1) and NaIL-10Rβ (OK149228.1)), whose full-length cDNA sequences were 2745bp (NaIL-10Rα) containing an ORF of 1755 bp that encoded a protein of 584 aa, and 1570bp (NaIL-10Rβ) with an ORF 975 bp encoding a protein of 324 aa, respectively. Both receptor subunits contained two extracellular fibronectin type Ⅲ (FNIII) domains, an intracellular domain and a transmembrane part, which are typical features of class Ⅱ cytokine receptor family. Real-time PCR analysis showed that NaIL-10Rα and NaIL-10Rβ were widely expressed in various healthy tissues, with a relatively high expression in immune-related organs (head kidney, spleen, kidney, liver and gill). Their expressions were significantly up-regulated after infection against Poly I:C, Vibrio parahaemolyticus and Vibrio alginolyticus. As a typical membrane receptor, NaIL-10Rα was located on the cell membrane and co-located with NaIL-10 and NaIL-10Rβ on the membrane of HEK293T cells, suggesting the potential interaction between those components. After successful isolation.