[Altered frequency of CD4+CD25-Foxp3+ T cells in patients with systemic lupus erythematosus].
OBJECTIVE
To investigate the expression pattern of circulating CD4+CD25-Foxp3+ T cells from the patients with systemic lupus erythematosus (SLE) in order to explore their role in disease pathogenesis.


METHODS
Lupus patients with new-onset active disease (n=15) and inactive disease (n=10) as well as healthy volunteers (n=15) were enrolled. The frequency of circulating CD4+CD25-Foxp3+ T cells and the level of CD127 expression on these cells were analyzed by flow cytometry. FOXP3 gene expression in purified CD4+CD25- T cell subset by MACS was assessed by real-time PCR.


RESULTS
The percentages of CD4+CD25-Foxp3+ T cells within CD4+ lymphocytes in active patients, inactive patients and healthy controls were (9.89+/-0.85)%, (7.11+/-0.86)% and (3.35+/-0.31)%, respectively. The frequency of CD4+CD25-Foxp3+ T cells in these lupus patients correlated positively with their SLEDAI (P=0.0008). Moreover, Foxp3 expressions, at both mRNA and protein levels, were increased in the purified CD4+CD25- T cell population from active patients compared to healthy controls (P<0.01). Most CD4+CD25-Foxp3+ T cells were found to be CD127(low).


CONCLUSIONS
Altered frequency of CD4+CD25-Foxp3+ T cells in lupus patients might attribute to the resistant effect on Treg suppression, one mechanism accounting for T cell loss of peripheral tolerance in the pathogenesis of SLE.
Yan
Bing
B
Department of Rheumatology, West China Hospital of Sichuan University, Chengdu 610041, China. yanbing732002@yahoo.com.cn
Liu
Yi
Y
Xie
Qi-bing
QB
Liu
Gang
G
D000293:Adolescent; D000328:Adult; D015704:CD4 Antigens; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology*; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology* / Q000473:pathology; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D055815:Young Adult
D015704:CD4 Antigens; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; C508017:IL2RA protein, human; D053645:Interleukin-2 Receptor alpha Subunit