TGF-β-Induced CD8 + CD103 + Regulatory T Cells Show Potent Therapeutic Effect on Chronic Graft-versus-Host Disease Lupus by Suppressing B Cells

Lupus nephritis is one of most severe complications of systemic erythematosus lupus and current approaches are not curative for lupus nephritis. Although CD4 Foxp3 regulatory T cells (Treg) are crucial for prevention of autoimmunity, the therapeutic effect of these cells on lupus nephritis is not satisfactory. We previously reported that CD8 CD103 Treg induced with TGF-β1 and IL-2 (CD8 CD103 iTreg), regardless of Foxp3 expression, displayed potent immunosuppressive effect on Th cell response and had therapeutic effect on Th cell-mediated colitis. Here, we tested whether CD8 CD103 iTreg can ameliorate lupus nephritis and determined potential molecular mechanisms. Adoptive transfer of CD8 CD103 iTreg but not control cells to chronic graft-versus-host disease with a typical lupus syndrome showed decreased levels of autoantibodies and proteinuria, reduced renal pathological lesions, lowered renal deposition of IgG/C3, and improved survival. CD8 CD103 iTreg cells suppressed not only T helper cells but also B cell responses directly that may involve in both TGF-β and IL-10 signals. Using RNA-seq, we demonstrated CD8 CD103 iTreg have its own unique expression profiles of transcription factors. Thus, current study has identified and extended the target cells of CD8 CD103 iTreg and provided a possible application of this new iTreg subset on lupus nephritis and other autoimmune diseases.