Conservation of structural and interactional features of CD226 and Necl5 molecules from Nile tilapia (Oreochromis niloticus). Issue 116 (September 2021)

• Record Type: Journal Article
• Authors: Xie, Caixia; Wang, Zhiwen; Li, Yuan; Wu, Fan; Lu, Yishan; Xia, Hongli; Tang, Jufen; Jian, Jichang; Kwok, Kevin WH.
• Is Part Of: Fish & shellfish immunology. Issue 116(2021)
• Page Start: 74
• Page End: 83
• Publication Date: 2021-09
• Subjects: CD226 -- Necl5 -- Nile tilapia -- T cell-dependent response -- Yeast two-hybrid; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2021.05.014
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: CD226 interacts with its ligand Necl5 as a costimulatory signal. In this study, we cloned a CD226 from Nile tilapia ( Oreochromis niloticus, named OnCD226) and a Necl5 (named OnNecl5). The open reading frame of OnCD226 was 1071 bp, encoding a protein of 356 amino acids. Sequence alignment analysis indicated that OnCD226 contained two Ig-like domains in ectodomain. The open reading frame of OnNecl5 was 1155 bp, encoding a protein of 384 amino acids, and there are three lg-like domains in the extracellular domain. In healthy tilapia, OnCD226 was distributed in all tested tissues and relatively higher in the brain, while OnNecl5 was relatively higher in the skin. After Streptococcus agalactiae infection, OnCD2 26 has the same up-regulated expression pattern as OnNecl5 in different tissues. After HKLs stimulation with S. agalactiae and Poly I:C, respectively. OnCD226 was significantly up-regulated (0.01 < p < 0.05) at 12 h and extremely significant up-regulation was observed ( p < 0.01) at 48 h and 96 h, the peak was observed at 96 h after stimulation by S. agalactiae . After stimulation by Poly I:C, OnCD226 expression was extremely significant ( p < 0.01) at 72 h and 96 h, the peak was observed at 96 h. After stimulation by Keyhole limpet hemocyanin (KLH), a classical T cell-dependent antigen, the expression of OnCD226 was significantly up-regulated in blood, head kidney, spleen, and thymus. Moreover, when compared with the first challenge, the gene expression of OnCD226 which response to the second challenge was up-regulated earlier. Subcellular co-localization studies showed that OnCD226 and OnNecl5 were distributed mainly in the cytomembrane. Yeast two-hybrid results, indicated a strong interaction between OnCD226 and OnNecl5. These results suggested that OnCD226 plays an important role during pathogens infection, and the interaction between CD226 and Necl5 is conserved in Nile tilapia. Highlights: Homologue of CD226 was identified from Nile tilapia, Oreochromis niloticus . CD226 could respond to bacteria and viral analogues challenge in immune tissue. CD226 was participated in host defense against T cell-dependent pathogen infection. The interaction between CD226 and Necl5 is conserved in Nile tilapia.