Expression of intracellular transforming growth factor-beta1 in CD4 + CD25 + cells in patients with systemic lupus erythematosus

+CD25 + regulatory T (Treg) cells exert immunoregulatory functions in various autoimmune diseases, in part through transforming growth factor-beta1 (TGF-β1), and can be expanded by TGF-β1 stimulation in normal subjects. This study aimed to examine intrinsic TGF-β1 expression and the response to TGF-β1 stimulation of this CD4 + CD25 + subset in patients with systemic lupus erythematosus (SLE). Methods: Flow cytometry with multicolor staining of CD4 + , CD25 + , and TGF-β1 was used to quantify the percentage of CD4 + CD25 + T cells in fresh peripheral blood and TGF-β1-stimulated peripheral blood mononuclear cell (PBMC) cultures, and their corresponding intracellular TGF-β1 expression. Results: In fresh peripheral blood, we found that decreased percentages of CD4 + CD25 + /CD4 + in SLE patients were associated with disease activity and renal involvement. Intracellular TGF-β1 expression of CD4 + CD25