Elevated apoptosis and impaired proliferation contribute to downregulated peripheral γ δ T cells in patients with systemic lupus erythematosus.
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.


CONCLUSIONS
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.
Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China.
Zhimin
Z
Lu
Dinglei
D
Su
Dandan
D
Wang
Xia
X
Li
Xuebing
X
Feng
Lingyun
L
Sun
D000293:Adolescent; D000328:Adult; D017209:Apoptosis / Q000276:immunology; D016022:Case-Control Studies; D049109:Cell Proliferation; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D042541:Intracellular Space / Q000378:metabolism; D008180:Lupus Erythematosus, Systemic / Q000276:immunology* / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism*; D055815:Young Adult
D016207:Cytokines; D016692:Receptors, Antigen, T-Cell, gamma-delta