The thioredoxin-1 system is essential for fueling DNA synthesis during T cell metabolic reprogramming and proliferation. The thioredoxin-1 system is essential for fueling DNA synthesis during T cell metabolic reprogramming and proliferation

The thioredoxin-1 (Trx1) system is a key player of the cellular redox balance and a sensor of energy and glucose metabolism. Here we report critical c-Myc-dependent activation of the Trx1 system during glucose-driven T cell expansion during development and immune responses but endogenous Trx1-repression during quiescence. Thioredoxin-reductase-1 (Txnrd1)-deletion in CD4-CD8- thymocytes prevented their expansion, while deletion in CD4+CD8+ thymocytes did not affect further maturation and peripheral homeostasis of T-cells. Moreover, B cell development was Txnrd1-independent. Txnrd1 was critical for expansion of activated T cells. Unbiased metabolomics revealed that Txnrd1 is necessary for donating reducing equivalent to ribonucleotide reductase (RNR) at the last step of nucleotide biosynthesis. Impaired availability of 2’-deoxyribonucleotides induced the DNA damage response and cell cycle arrest of Txnrd1-deficient T cells. These results uncover a pivotal role of the Trx1 system in metabolic reprograming of thymic and peripheral T cells and provide a rationale for targeting of Txnrd1 in T-cell leukemia. Overall design: We compared naive and SEB-stimulated WT and Txnrd1-deficient CD8+ T cells. In total we have 4 conditions (WT & KO, and naive & SEB-stimulated). Each condition has 2 biological replicates.