Control of regulatory T cell function by the non-oxidative pentose phosphate pathway [ATAC-seq]

Non-oxidative pentose phosphate pathway (PPP) is a crucial gatekeeper of glucose catabolism in metabolic tissues. However, its role in regulatory T cells (Tregs) remains unknown. Here we report deleting transketolase (TKT), an indispensable enzyme of non-oxidative PPP, in Tregs caused a fatal auto-immune disease in mice. TKT deletion impaired suppressive capability without disturbing Treg cell number. Mechanistically, TKT deficiency caused Treg metabolic remodeling with decreased glucose catabolism, activated fatty acid and amino acid catabolism and uncontrolled oxidative phosphorylation. Moreover, excessive ammonia from deregulated amino acid catabolism impaired mitochondrial fitness while reduced a-ketoglutarate/succinate ratio led to DNA hypermethylation, limiting functional gene expression and suppressive activity of TKT-deficient Tregs. Therefore, our study identifies non-oxidative PPP as a new pathway for controlling Treg function. Overall design: 50,000 CD4+CD25+YFP+ Tregs were isolated from 7-week-old chimeric female WT and cKO mice by FACS and washed once with 50 µl cold PBS buffer. Supernatant was discarded by centrifugation at 500 g, 4oC for 5 min. Lysed the cell pellet in 50 µl cold lysis buffer (10 mM NaCl, 10 mM pH7.4 Tris-HCl; 0.5%NP-40 and 3mM MgCl2) and centrifuge immediately at 500g, 4°C for 10 min. Transposition reaction and purification PCR amplification were performed using Nextera XT DNA Library Preparation Kit (Illumina, Cat. #FC-131-1096) and Qiagen MinElute PCR Purification Kit (Qiagen, Cat. #28004). Illumina Novaseq 6000 was used for sequencing.