{"doi":"10.1093/jimmun/vkag038","title":"Genomic organization of the TCRα locus and essential roles of αβ T cells in antibacterial immunity in Nile tilapia","abstract":"<jats:title>Abstract</jats:title>\n                  <jats:p>T cells utilize diverse T cell receptors (TCRs) to recognize antigenic peptides and mediate adaptive immunity. However, the organization and function of αβ T cells in early vertebrates remain poorly understood. Here, we systematically characterized the TCRα locus and αβ T cell responses in Nile tilapia (Oreochromis niloticus) during Edwardsiella piscicida infection. Genomic analysis revealed that the TCRα locus in Nile tilapia exhibits a distinctive Vα(61)-Jα(82)-Cα(1)-Vα(65) structure with conserved synteny in the flanking regions, while the constant region retains essential residues for TCR/CD3 complex assembly. We further generated monoclonal antibody against tilapia TCRα and TCRβ and confirmed their coexpression by the majority of CD3ε+ T cells, validating these cells as bona fide αβ T cells. Functional assays showed that CD3ε/CD28 monoclonal antibody stimulation induced robust αβ T cell activation, as evidenced by enhanced phosphorylation of S6, NF-κB, and ERK1/2, together with vigorous cellular proliferation. In vivo, E. piscicida infection triggered a pronounced expansion of αβ T cells, indicating their active involvement in antibacterial immunity. Importantly, depletion of αβ T cells severely impaired pathogen clearance and significantly increased host mortality. Together, these findings elucidate the indispensable role of αβ T cells in the antibacterial immunity of teleosts and provide critical insights into the functional mechanisms of adaptive immunity in early vertebrates.</jats:p>","journal":"The Journal of Immunology","year":2026,"id":613203,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":431014,"name":"Kang Li","orcid":"0000-0003-1893-4074","position":1,"is_corresponding":false},{"id":142132,"name":"Jiansong Zhang","orcid":"0000-0002-6960-0667","position":2,"is_corresponding":false},{"id":1579569,"name":"Yuying Zheng","orcid":null,"position":3,"is_corresponding":false},{"id":1579570,"name":"Haokai Chen","orcid":null,"position":4,"is_corresponding":false},{"id":1579571,"name":"Qiqi Jiang","orcid":null,"position":5,"is_corresponding":false},{"id":379411,"name":"Jialong Yang","orcid":"0000-0002-3112-5012","position":6,"is_corresponding":false},{"id":1579572,"name":"Xiumei Wei","orcid":"0000-0002-2253-8181","position":7,"is_corresponding":false},{"id":1579568,"name":"Ming Geng","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Genomic organization of the TCRα locus and essential roles of αβ T cells in antibacterial immunity in Nile tilapia","abstract":"<jats:title>Abstract</jats:title>\n                  <jats:p>T cells utilize diverse T cell receptors (TCRs) to recognize antigenic peptides and mediate adaptive immunity. However, the organization and function of αβ T cells in early vertebrates remain poorly understood. Here, we systematically characterized the TCRα locus and αβ T cell responses in Nile tilapia (Oreochromis niloticus) during Edwardsiella piscicida infection. Genomic analysis revealed that the TCRα locus in Nile tilapia exhibits a distinctive Vα(61)-Jα(82)-Cα(1)-Vα(65) structure with conserved synteny in the flanking regions, while the constant region retains essential residues for TCR/CD3 complex assembly. We further generated monoclonal antibody against tilapia TCRα and TCRβ and confirmed their coexpression by the majority of CD3ε+ T cells, validating these cells as bona fide αβ T cells. Functional assays showed that CD3ε/CD28 monoclonal antibody stimulation induced robust αβ T cell activation, as evidenced by enhanced phosphorylation of S6, NF-κB, and ERK1/2, together with vigorous cellular proliferation. In vivo, E. piscicida infection triggered a pronounced expansion of αβ T cells, indicating their active involvement in antibacterial immunity. Importantly, depletion of αβ T cells severely impaired pathogen clearance and significantly increased host mortality. Together, these findings elucidate the indispensable role of αβ T cells in the antibacterial immunity of teleosts and provide critical insights into the functional mechanisms of adaptive immunity in early vertebrates.</jats:p>","is_dataset_classified":null,"base_score":0.0,"endowment":0.0,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"42001518","pmcid":null,"openalex_id":"https://openalex.org/W7154888305","authors":[],"funders":[{"funder_name":"Natural Science Foundation of Shanghai","grant_id":"24ZR1419700","title":null},{"funder_name":"China Postdoctoral Science Foundation","grant_id":"2025T180854","title":null},{"funder_name":"Postdoctoral Fellowship Program of China Postdoctoral Science Foundation","grant_id":"GZB20250722","title":null}],"total_grants":3,"fwci":0.0,"citation_percentile":0.34652259,"influential_citations":0,"citation_trend":[],"oa_status":"closed","license":"https://academic.oup.com/pages/standard-publication-reuse-rights","oa_locations":[{"url":"https://academic.oup.com/jimmunol/article-pdf/215/4/vkag038/68112080/vkag038.pdf","host_type":"publisher"},{"url":"https://doi.org/10.1093/jimmun/vkag038","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/42001518","host_type":"repository"}],"fields_of_study":["T-cell and B-cell Immunology","Aquaculture disease management and microbiota","Immune Cell Function and Interaction","Animals","Receptors, Antigen, T-Cell, alpha-beta","Edwardsiella","Cichlids","Enterobacteriaceae Infections","Lymphocyte Activation","T-Lymphocytes","Fish Diseases","Edwardsiella piscicida"],"mesh_terms":["Animals","Enterobacteriaceae Infections","Fish Diseases","Lymphocyte Activation","T-Lymphocytes","Receptors, Antigen, T-Cell, alpha-beta","Edwardsiella","Cichlids","Adaptive Immunity"],"keywords":["Monoclonal antibody","Acquired immune system","Nile tilapia","Immunity","Immune system","Locus (genetics)","Cellular immunity","T cell","Tilapia","Antibacterial Immunity","Αβ T Cell","Tcrα Locus"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Good health and well-being"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-02T07:05:58.328280Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}