CD4⁺CD57⁺ senescent T cells as promoters of systemic lupus erythematosus pathogenesis and the therapeutic potential of senolytic BCL‐2 inhibitor

Abstract

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by persistent activation of immune cells and overproduction of autoantibodies. The accumulation of senescent T and B cells has been observed in SLE and other immune-mediated diseases. However, the exact mechanistic pathways contributing to this process in SLE remain incompletely understood. In this study, we found that in SLE patients: (1) the frequency of CD4⁺CD57⁺ senescent T cells was significantly elevated and positively correlated with disease activity; (2) the expression levels of B-lymphoma-2 (BCL-2) family and interferon-induced genes (ISGs) were significantly upregulated; and (3) in vitro, the cytokine IL-15 stimulation increased the frequency of senescent CD4⁺ T cells and upregulated the expression of BCL-2 family and ISGs. Further, treatment with ABT-263 (a senolytic BCL-2 inhibitor) in MRL/lpr mice resulted in decreased: (1) frequency of CD4⁺CD44^hiCD62L^-PD-1⁺CD153⁺ senescent CD4⁺ T cells; (2) frequency of CD19⁺CD11c⁺T-bet⁺ age-related B cells; (3) level of serum antinuclear antibody; (4) proteinuria; (5) frequency of Tfh cells; and (6) renal histopathological abnormalities. Collectively, these results indicated a dominant role for CD4⁺CD57⁺ senescent CD4⁺ T cells in the pathogenesis of SLE and senolytic BCL-2 inhibitor ABT-263 may be the potential treatment in ameliorating lupus phenotypes.