Interleukin-8 involved in Nile Tilapia (Oreochromis niloticus) against bacterial infection

Interleukin 8 ( IL8 ) is vital in promoting inflammation and is a crucial mediator in various physiopathological processes while influencing immunological function. The effect of IL8 on the immunological response to acute bacterial infections in Nile tilapia ( Oreochromis niloticus) remains unknown. This work found an IL8 gene from Nile tilapia ( On-IL8 ). It includes a 285 bp open reading frame and codes for 94 amino acids. The transcript levels of On-IL8 were highest in the head-kidney tissue and sharply induced by Streptococcus agalactiae and Aeromonas hydrophila . Besides, in vitro experiments revealed that On-IL8 regulated a variety of immunological processes and promoted inflammatory responses. Moreover, On-IL8 suppressed the NF-κB signaling pathway , consistent with in vitro results. These significant findings serve as the basis for further investigation into how IL8 confers protection to bony fish in opposition to bacterial infections.