Objective: To investigate the frequency of peripheral γ δ T cells in patients with systemic lupus erythematosus (SLE) and its correlation with disease activity and to analyze the apoptotic status, proliferation ability, and intracellular cytokine profile of these cells.
Methods: Flow cytometry was performed to detect the percentage and intracellular cytokine expression of peripheral γ δ T cells from SLE patients. Annexin-V/PI double staining was applied to determine the proportion of apoptotic γ δ and CD3(+) T cells. γ δ T cell proliferation was analyzed by CFSE labeling technique.
Results: The percentage and absolute number of γ δ T cells were remarkably decreased in active SLE patients compared to those in inactive patients and healthy controls, with γ δ T cell count negatively correlated with disease activity. Compared with healthy controls, peripheral γ δ T cells from active SLE patients exhibited higher apoptotic rate and lower proliferation ability, as well as elevated expression of intracellular IFN-γ , IL-4, IL-10, and TGF- β , but not IL-17 or Foxp3.
Conclusion: Decreased γ δ T cells in the peripheral blood of SLE patients might be caused by upregulated apoptosis and downregulated cell proliferation. These γ δ T cells may secret both pro- and anti-inflammatory cytokines to perform their functions in SLE.