Molecular characterization and expression of CD96 in Nile tilapia (Oreochromis niloticus) in response to different pathogens stimulus

CD96 is one of the immune superfamily members and it identified as a T cell-specific receptor. In this study, we cloned from Nile tilapia (Oreochromis niloticus, named OnCD96). The open reading frame OnCD96was 1371 bp, encoding protein 456 amino acids. Sequence alignment analysis indicated that OnCD96 contained two Ig-like domains in entodomain, proline-rich motif, ITIM motif cytoplasm. Subcellular localization studies showed was distributed mainly cytoplasm on cytoplasmic membrane. healthy tilapia, all tested tissues relatively higher liver. After Streptococcus agalactiae infection, expression thymus, brain, spleen reached its peak at 72 h, 48 24 respectively. stimulation with poly I:C, thymus 6 h While, brain had double peaks, which were 96 h. Keyhole limpet hemocyanin (KLH), classical cell-dependent antigen, significantly up-regulated blood head kidney. Moreover, compared first challenge, earlier after second challenge. Yeast two-hybrid assay there might be interaction between OnNecl5. These results suggested plays an important role during pathogens Necl5 conserved tilapia.