{"doi":"10.3390/cells13030234","title":"Investigation into Cardiac Myhc-α 334–352-Specific TCR Transgenic Mice Reveals a Role for Cytotoxic CD4 T Cells in the Development of Cardiac Autoimmunity","abstract":"Myocarditis is one of the major causes of heart failure in children and young adults and can lead to dilated cardiomyopathy. Lymphocytic myocarditis could result from autoreactive CD4+ and CD8+ T cells, but defining antigen specificity in disease pathogenesis is challenging. To address this issue, we generated T cell receptor (TCR) transgenic (Tg) C57BL/6J mice specific to cardiac myosin heavy chain (Myhc)-α 334–352 and found that Myhc-α-specific TCRs were expressed in both CD4+ and CD8+ T cells. To investigate if the phenotype is more pronounced in a myocarditis-susceptible genetic background, we backcrossed with A/J mice. At the fourth generation of backcrossing, we observed that Tg T cells from naïve mice responded to Myhc-α 334–352, as evaluated by proliferation assay and carboxyfluorescein succinimidyl ester staining. The T cell responses included significant production of mainly pro-inflammatory cytokines, namely interferon (IFN)-γ, interleukin-17, and granulocyte macrophage-colony stimulating factor. While the naïve Tg mice had isolated myocardial lesions, immunization with Myhc-α 334–352 led to mild myocarditis, suggesting that further backcrossing to increase the percentage of A/J genome close to 99.99% might show a more severe disease phenotype. Further investigations led us to note that CD4+ T cells displayed the phenotype of cytotoxic T cells (CTLs) akin to those of conventional CD8+ CTLs, as determined by the expression of CD107a, IFN-γ, granzyme B natural killer cell receptor (NKG)2A, NKG2D, cytotoxic and regulatory T cell molecules, and eomesodermin. Taken together, the transgenic system described in this report may be a helpful tool to distinguish the roles of cytotoxic cardiac antigen-specific CD4+ T cells vs. those of CD8+ T cells in the pathogenesis of myocarditis.","journal":"Cells","year":2024,"id":441822,"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":8,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9485,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":648038,"name":"Mahima T. Rasquinha","orcid":"0000-0003-0923-4869","position":1,"is_corresponding":false},{"id":1053129,"name":"Kiruthiga Mone","orcid":"0000-0003-0379-4152","position":2,"is_corresponding":false},{"id":494192,"name":"Chandirasegaran Massilamany","orcid":"0000-0002-0205-282X","position":3,"is_corresponding":false},{"id":494191,"name":"Ninaad Lasrado","orcid":"0000-0001-6762-2654","position":4,"is_corresponding":false},{"id":391888,"name":"Channabasavaiah B. Gurumurthy","orcid":null,"position":5,"is_corresponding":false},{"id":6938,"name":"Raymond A. Sobel","orcid":"0000-0002-0477-9002","position":6,"is_corresponding":false},{"id":494196,"name":"Jay Reddy","orcid":"0000-0003-4082-9254","position":7,"is_corresponding":false},{"id":648039,"name":"Meghna Sur","orcid":"0000-0003-0878-4930","position":0,"is_corresponding":true}],"reference_count":72,"raw_metadata":null,"created_at":"2026-07-19T02:01:11.152920Z","pmid":"38334626","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":[]}