ZAP70 activation is an early event of T cell immunity that involved in the anti-bacterial adaptive immune response of Nile tilapia

• Published in: Developmental and comparative immunology 2021-11, Vol.124, p.104177-104177, Article 104177
• Main Authors: Li, Jiaqi, Liang, Wei, Li, Kang, Jiao, Xinying, Ai, Kete, Zhang, Yu, Wei, Xiumei, Yang, Jialong
• Format: Article
• Language: English
• Subjects: Adaptive Immunity; Amino Acid Sequence; Animals; Antigens; Antiinfectives and antibacterials; Bacteria; Bacterial Infections - immunology; Bacterial Infections - veterinary; Cell activation; Cichlids - immunology; Evolution; Fish Diseases - immunology; Fish Proteins - chemistry; Fish Proteins - genetics; Fish Proteins - immunology; Fish Proteins - metabolism; Gene Expression; Immune response; Immune response (cell-mediated); Immune system; Immunity; Lymphocyte Activation; Lymphocytes; Lymphocytes T; Lymphoid tissue; Oreochromis niloticus; Phosphorylation; Phylogeny; Ponds; Protein Structure, Tertiary; Spleen; Synteny; T cell receptors; T-Lymphocytes - immunology; Tilapia; Tissue Distribution; Transcription; Vertebrates; ZAP-70 protein; ZAP-70 Protein-Tyrosine Kinase - chemistry; ZAP-70 Protein-Tyrosine Kinase - genetics; ZAP-70 Protein-Tyrosine Kinase - immunology; ZAP-70 Protein-Tyrosine Kinase - metabolism; Zap70
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2021.104177

ZAP70 is essential for initiating the early events of T-cell antigen receptor (TCR) signaling cascade to ensure proper T cell activation and function. However, whether this molecule takes part in the T cell immune response of early vertebrates remains unclear. In the present study, using a teleost model Nile tilapia (Oreochromis niloticus), we investigated the potential involvement of ZAP70 in the T cell activation and adaptive immunity of fish species. Both primary and tertiary structures of O. niloticus ZAP70 (On-ZAP70) are highly conserved with those from other vertebrates. On-ZAP70 protein was widely expressed in lymphoid tissues, and with the highest level in thymus. Once Nile tilapia was infected by Aeromonas hydrophila, mRNA of On-ZAP70 in spleen lymphocytes was induced on day 5 and 8 after infection; meanwhile, phosphorylation of On-ZAP70 was also enhanced, suggesting that On-ZAP70 potentially participated in primary adaptive immune response of Nile tilapia. Furthermore, the frequency of ZAP70 positive lymphocytes was increased during the anti-bacterial adaptive immune response. More importantly, when spleen lymphocytes were activated by T cell specific mitogen PHA, a dramatical augment of On-ZAP70 could be observed at transcription, phosphorylation and cellular level, indicating the involvement of this molecule in T cells activation of Nile tilapia. Altogether, our results demonstrated that ZAP70 activation is an early event of T cell immunity that involved in the anti-bacterial adaptive immune response of Nile tilapia, and thus provided a new evidence to understand the evolution of the lymphocyte-mediated adaptive immunity. •The protein of Nile tilapia ZAP70 expresses widely in lymphoid tissues.•OnZAP70 takes part in primary response of the adaptive immunity.•ZAP70+ lymphocytes increase during adaptive immune response of Nile tilapia.•ZAP70 activation is an early event for T cell immunity of Nile tilapia.