Addressing the repertoire of T helper Cells in the context of myocardial infarction

T-cells can influence the post-myocardial infarction healing process. The fundamental role of T cells in adaptive immunity relies mainly on a diverse repertoire of T cell receptor (TCR) a and ß chains that display unique antigen specificities. Thus, we performed high-throughput sequencing of the TCRß chains on CD4+ T cells purified by fluorescence-activated cell sorting (FACS) from the heart and med-LNs of MI and sham-operated mice as an unbiased approach to screen for MI-related TCR signatures. Overall design: Experimental myocardial infarction (EMI) was induced in Balb/c WT mice by means of ligating the left anterior descending coronary artery. As a sham-operation control, animals were subjected to thoracotomy without coronary ligation. CD4+ T-cells were purified (FACS) from the mediastinal lymph nodes (med-LN, heart-draining) of from the infarcted heart at day 7 post-operation. In addition, we assessed the TCRb repertoire of CD4+ T cells purified from the axillary LNs (ax-LNs) of mice receiving subcutaneous immunization with cardiac myosin and heart extract (in adjuvants), as these repertoires were expected to be enriched in heart-specific sequences upon specific immunization. As a control, we also assessed the ax-LN TCRb repertoire in mice that received subcutaneous administration of the adjuvant alone.