Targeting tissue-resident memory CD8+ T cells in the kidney is a potential therapeutic strategy to ameliorate podocyte injury and glomerulosclerosis

Although tissue-resident-memory T (T) cells, a recently identified non-circulating memory T cell population, play a crucial role in mediating local immune responses and protect against pathogens upon local reinfection, the composition, effector function, and specificity of T cells in the kidney and their relevance for chronic kidney disease remain unknown. In this study, we found that renal tissue displayed high abundance of tissue-resident lymphocytes, and the proportion of CD8 T cells was significantly increased in the kidney from patients and mice with focal segmental glomerulosclerosis (FSGS), diabetic kidney disease (DKD), and lupus nephritis (LN). Mechanistically, IL-15 significantly promoted CD8 T cell formation and activation, thereby promoting podocyte injury and glomerulosclerosis. Interestingly, Sparsentan, the dual angiotensin II (Ang II) receptor and endothelin type A receptor antagonist, can also reduce T cell responses by intervening IL-15 signaling, exploring its new pharmacological functions. Mechanistically, Sparsentan inhibited Ang II or endothelin-1 (ET-1)-mediated IL-15 signaling, thereby further regulating renal CD8 T cell fates. Collectively, our studies provide direct evidence for the pivotal role of renal CD8 T cells in podocyte injury and further strengthen that targeting T cells represents a novel therapeutic strategy for patients with glomerular diseases.