BACKGROUND

Regulatory T (Treg) cells are one of the important mechanisms in maintaining self-tolerance and immune homeostasis. CD4CD25Foxp3Treg is considered to have a role in the pathogenesis of systemic lupus erythematosus (SLE). However, the data reported is controversial, and a conclusive result has not been given thus far. The aim of the present study is to evaluate the role of CD4Treg in SLE further.

METHODS

The peripheral blood T cells (PBMCs) from patients with SLE and healthy controls were isolated, and followed by the isolation of CD3T cells. The PBMCs were tested for the expressions of CD25 and Foxp3 molecules on the surface of CD4T cells, and CD3T cells were tested for their cytokine expressions including IFN-γ, TGF-β, and IL-10, with the method of flow cytometry. The correlations of test results with clinical features of the disease were evaluated by linear correlation analysis.

RESULTS

CD4CD25 Foxp3Treg decreased in SLE patients and was correlated with the SLE Disease Activity Index (SLEDAI), and a few immunological abnormalities, including anti-dsDNA antibody positive, IgG increase and C3 decrease, and types of tissue damage, including leukocytopenia and kidney damage. IFN-γ cells in the CD4CD25T subset fresh-isolated from SLE patients increased slightly, but IFN-γ-producing response to stimulation in CD4CD25T subset of SLE decreased. The number of TGF-β-producing cells in the CD4CD25T subset from SLE patients also decreased. While the percentages of CD4CD25IL-10T subset in the CD3T cells increased in SLE, however, these changes of cytokine expressions did not show any significant correlations with SLEDAI.

CONCLUSIONS

There is clear and definite evidence from the present study indicating the important role of CD4CD25Foxp3Treg in the pathogenesis of SLE, for the abnormalities in functional cytokine productions of the CD4CD25 T subset, and for the feasibility of a CD4CD25Foxp3Treg- based immunotherapy in SLE.