Advances in chemokines of teleost fish species

In mammals, chemokines are a superfamily of cytokines that regulate cell migration or exert direct antimicrobial activity. The presence and organization of four invariant cysteine residues within the mature protein sequence can classify chemokines into four major subfamilies: CXC, CC, CX3C, and XC. In teleost, a novel subfamily of chemokines named CX has been identified. Since the first report of a CC chemokine (CK1) in rainbow trout in 1998, the number of identified chemokine genes in different fish species has expanded dramatically. In this paper, we reviewed the chemokine genes that have been identified so far in teleost fish and their tissue expressions and responses post-stimulation. We also discussed the functions of fish chemokines based on currently available information and compared them to human chemokines. Additionally, we predicted the structures of trout chemokines for the first time, and we found that the structures of trout chemokines share significant similarities. Finally, the adjuvant effects of fish chemokines in aquaculture were also reviewed. Overall, this review will give us a better understanding of the chemokines of teleost fish.