{"doi":"10.3389/fimmu.2021.704324","title":"Identification and Characterization of a Master Transcription Factor of Th1 Cells, T-bet, Within Flounder (Paralichthys olivaceus)","abstract":"<jats:p>T-bet, a T-box family member, is a transcription factor essential for the differentiation of naive CD4<jats:sup>+</jats:sup> T cells into Th1 cells that are involved in both innate and adaptive immune responses. In this study, the transcription factor T-bet of flounder (<jats:italic>Paralichthys olivaceus</jats:italic>) was cloned and characterized, and its expression profile after infection was analyzed. T-bet<jats:sup>+</jats:sup> cells were identified in flounder, and the expression and localization of T-bet in T lymphocyte subsets and B lymphocytes were investigated. Finally, the proliferation of T-bet<jats:sup>+</jats:sup> cells, T lymphocyte subsets, and B lymphocytes were studied after stimulation with IFN-γ, IL-2, and IL-6, respectively, and the variations of some transcription factors and cytokines in CD4<jats:sup>+</jats:sup> T lymphocyte subsets were detected. The results showed that T-bet in flounder consists of 619 aa with a conserved T-box DNA binding domain. T-bet was abundantly expressed in the spleen, head kidney, and heart, and it was significantly upregulated after infection with <jats:italic>Vibrio anguillarum, Edwardsiella tarda</jats:italic>, and Hirame rhabdovirus, especially in the group of <jats:italic>Edwardsiella tarda</jats:italic>. A polyclonal antibody against recombinant protein of T-bet was prepared, which specifically recognized the natural T-bet molecule in flounder. T-bet<jats:sup>+</jats:sup> cells were found to be distributed in the lymphocytes of peripheral blood, spleen, and head kidney, with the highest proportion in spleen, and the positive signals of T-bet occurred in the cell nucleus. T-bet was also detected in the sorted CD4-1<jats:sup>+</jats:sup>, CD4-2<jats:sup>+</jats:sup>, CD8<jats:sup>+</jats:sup> T lymphocytes, and IgM<jats:sup>+</jats:sup> B lymphocytes. In addition, T-bet<jats:sup>+</jats:sup> cells, coordinated with CD4-1<jats:sup>+</jats:sup> and CD4-2<jats:sup>+</jats:sup> T lymphocytes, were proliferated after stimulation with IFN-γ, IL-2, and IL-6. Especially in sorted CD4-1<jats:sup>+</jats:sup> and CD4-2<jats:sup>+</jats:sup> T lymphocytes, IFN-γ and IL-2 were able to upregulate the expression of T-bet, forming a positive feedback loop in Th1-type cytokine secretion. These results suggest that T-bet may act as a master transcription factor regulating flounder CD4<jats:sup>+</jats:sup> T lymphocytes involved in a Th1-type immune response.</jats:p>","journal":"Frontiers in Immunology","year":2021,"id":641353,"datarank":0.4943755299006494,"base_score":3.295836866004329,"endowment":3.295836866004329,"self_citation_contribution":0.4943755299006494,"citation_network_contribution":0.0,"self_endowment_contribution":0.4943755299006494,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":26,"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":114858,"name":"Jing Xing","orcid":null,"position":1,"is_corresponding":false},{"id":1667502,"name":"Xiaoqian Tang","orcid":null,"position":2,"is_corresponding":false},{"id":1667503,"name":"Heng Chi","orcid":null,"position":3,"is_corresponding":false},{"id":1667504,"name":"Xiuzhen Sheng","orcid":null,"position":4,"is_corresponding":false},{"id":1667505,"name":"Wenbin Zhan","orcid":null,"position":5,"is_corresponding":false},{"id":1667501,"name":"Hongfei Tian","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Identification and Characterization of a Master Transcription Factor of Th1 Cells, T-bet, Within Flounder (Paralichthys olivaceus)","abstract":"<jats:p>T-bet, a T-box family member, is a transcription factor essential for the differentiation of naive CD4<jats:sup>+</jats:sup> T cells into Th1 cells that are involved in both innate and adaptive immune responses. In this study, the transcription factor T-bet of flounder (<jats:italic>Paralichthys olivaceus</jats:italic>) was cloned and characterized, and its expression profile after infection was analyzed. T-bet<jats:sup>+</jats:sup> cells were identified in flounder, and the expression and localization of T-bet in T lymphocyte subsets and B lymphocytes were investigated. Finally, the proliferation of T-bet<jats:sup>+</jats:sup> cells, T lymphocyte subsets, and B lymphocytes were studied after stimulation with IFN-γ, IL-2, and IL-6, respectively, and the variations of some transcription factors and cytokines in CD4<jats:sup>+</jats:sup> T lymphocyte subsets were detected. The results showed that T-bet in flounder consists of 619 aa with a conserved T-box DNA binding domain. T-bet was abundantly expressed in the spleen, head kidney, and heart, and it was significantly upregulated after infection with <jats:italic>Vibrio anguillarum, Edwardsiella tarda</jats:italic>, and Hirame rhabdovirus, especially in the group of <jats:italic>Edwardsiella tarda</jats:italic>. A polyclonal antibody against recombinant protein of T-bet was prepared, which specifically recognized the natural T-bet molecule in flounder. T-bet<jats:sup>+</jats:sup> cells were found to be distributed in the lymphocytes of peripheral blood, spleen, and head kidney, with the highest proportion in spleen, and the positive signals of T-bet occurred in the cell nucleus. T-bet was also detected in the sorted CD4-1<jats:sup>+</jats:sup>, CD4-2<jats:sup>+</jats:sup>, CD8<jats:sup>+</jats:sup> T lymphocytes, and IgM<jats:sup>+</jats:sup> B lymphocytes. In addition, T-bet<jats:sup>+</jats:sup> cells, coordinated with CD4-1<jats:sup>+</jats:sup> and CD4-2<jats:sup>+</jats:sup> T lymphocytes, were proliferated after stimulation with IFN-γ, IL-2, and IL-6. Especially in sorted CD4-1<jats:sup>+</jats:sup> and CD4-2<jats:sup>+</jats:sup> T lymphocytes, IFN-γ and IL-2 were able to upregulate the expression of T-bet, forming a positive feedback loop in Th1-type cytokine secretion. These results suggest that T-bet may act as a master transcription factor regulating flounder CD4<jats:sup>+</jats:sup> T lymphocytes involved in a Th1-type immune response.</jats:p>","is_dataset_classified":null,"base_score":3.295836866004329,"endowment":3.295836866004329,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"34262572","pmcid":"PMC8273736","openalex_id":"https://openalex.org/W3176200321","authors":[],"funders":[],"total_grants":0,"fwci":1.3198,"citation_percentile":0.79488361,"influential_citations":0,"citation_trend":[{"year":2021,"count":1},{"year":2022,"count":9},{"year":2023,"count":6},{"year":2024,"count":2},{"year":2025,"count":4},{"year":2026,"count":4}],"oa_status":"gold","license":"cc-by","oa_locations":[{"url":"https://www.frontiersin.org/articles/10.3389/fimmu.2021.704324/pdf","host_type":"journal"},{"url":"https://www.frontiersin.org/articles/10.3389/fimmu.2021.704324/pdf","host_type":"publisher"},{"url":"https://www.frontiersin.org/articles/10.3389/fimmu.2021.704324/full","host_type":"publisher"},{"url":"https://doi.org/10.3389/fimmu.2021.704324","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/34262572","host_type":"repository"},{"url":"https://doaj.org/article/e8bef256c2cb4741b8107911d93eeefa","host_type":"repository"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/8273736","host_type":"repository"},{"url":"https://europepmc.org/articles/PMC8273736","host_type":"Europe_PMC"},{"url":"https://europepmc.org/articles/PMC8273736?pdf=render","host_type":"Europe_PMC"}],"fields_of_study":["Immune Cell Function and Interaction","Aquaculture disease management and microbiota","T-cell and B-cell Immunology","Animals","CD8-Positive T-Lymphocytes","Cytokines","Fish Diseases","Fish Proteins","Flounder","T-Box Domain Proteins","Th1 Cells","T-bet Transcription Factor"],"mesh_terms":["T-bet Transcription Factor","Animals","Fish Diseases","Flounder","Cytokines","CD8-Positive T-Lymphocytes","Th1 Cells","T-Box Domain Proteins","Fish Proteins"],"keywords":["Biology","Edwardsiella tarda","Molecular biology","Flounder","T cell","CD8","Immune system","Immunology","Gene","Fishery","Biochemistry","Differentiation","Cytokines","Paralichthys Olivaceus","T-box Expressed In T Cells","T Helper Type 1 Cells"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Life below water"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[{"name":"gen"},{"name":"refseq"},{"name":"uniprot"}],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-07T17:27:37.106941Z","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":[]}