Going to the source: pancreatic lymph nodes maintain stem-like CD8+ T cells in human type 1 diabetes

Where does autoimmune persistence reside in type 1 diabetes (T1D)? Detailed investigation of the pancreas and pancreatic lymph nodes (PLNs) may provide more definitive answers, yet most studies in these target tissues have been confined to mouse models. In nonobese diabetic (NOD) mice, disease development is prevented by PLN ablation, and these LNs harbor a stem-like population of autoreactive CD8+ T cells. In this issue, Peters et al. identified stem-like CD8+ T cell populations enriched in PLNs from humans with T1D and provide evidence for a developmental continuum linking lymphoid and pancreatic immune compartments. Their findings extend concepts previously established in NOD mice and in cancer immunology to humans with T1D, wherein self-renewing T cell populations sustain long-term immune responses. While the precise relationship between these stem-like cells and pathogenic autoreactive clones remains unresolved, this work positions the PLN as a potential reservoir of autoimmune persistence in T1D and a target for immune intervention.