Costimulatory Molecules CD80/86 Trigger Non-Specific Cytotoxic Cell of Nile tilapia (Oreochromis niloticus) to Kill CIK Cells

The teleost non-specific cytotoxic cell (NCC), as the evolutionary precursors of NK cells, is an important population in innate immune system teleost. We have recently realized that costimulatory CD80/86 conservation structural and interactional features with its ligand CD28 Nile tilapia (Oreochromis niloticus). However, ability to regulate NCC activity has not been fully investigated. In present study, we first obtained recombinant fusion protein from O. niloticus (rOn-CD80/86). Then, incubation rOn-CD80/86 resulted a significant production effector cytokines, including tumor necrosis factor-alpha, cellular apoptosis susceptibility NK-lysin. Furthermore, treatment could significantly improve kill kidney cells Grass carp (CIK) up-regulate activities caspase-1 caspase-3 CIKs. yeast, two-hybrid assay showed On-CD80/86 cannot directly interact receptor protein-1 (On-NCCRP-1). single-cell RNA-Seq data head lymphocytes analysis found On-CD28 did exhibit expression on NCCs subsets. above results suggest molecules independent On-NCCRP-1 modulating killing vitro tilapia. also provide more insights into mechanism regulation.