Role of Stem Cell–Like Memory T Cells in Systemic Lupus Erythematosus

Objective Stem cell–like memory T (Tscm) cells are long‐lived memory T cells that have multipotent capacity to differentiate into different subsets. However, the role of Tscm cells in autoimmune diseases remains unclear. Here, we performed phenotypic studies to identify Tscm cells in patients experiencing systemic lupus erythematosus ( SLE ). Methods CD 4+ and CD 8+ Tscm cells were identified in SLE patients and healthy controls ( HC s). In in vitro culture systems, CD 4+ Tscm cells were induced to differentiate into subsets of T cells, including follicular helper T (Tfh) cells, and cytokine production patterns were assessed after stimulation. After confirming induction of transcription factors for Tfh cells, the capacity of CD 4+ Tscm‐derived Tfh cells to help B cells was analyzed by measuring antibody secretion. Results The percentages of CD 4+ and CD 8+ Tscm cells among the naive CD 4+/ CD 8+ or total CD 4+ T cell populations were significantly higher in SLE patients than in HC s. Stimulated Tscm cells from SLE patients could replenish themselves and differentiate into other T lymphocyte subsets, including Tfh cells upon stimulation with T cell receptor. Production of T cell factor 1, which is an inducer of Tfh, was also increased. The differentiated Tfh cells increased antibody production by autologous B cells. Conclusion Taken together, these findings suggest that Tscm cells play a role in the pathogenesis of SLE by maintaining Tfh cells.