Expression of surface markers on peripheral CD4+CD25high T cells in patients with atopic asthma: role of inhaled corticosteroid.
BACKGROUND
CD4(+)CD25(+) regulatory T cells (Tregs) mediate immune suppression through cell-cell contact with surface molecules, particularly cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), glucocorticoid-induced tumor necrosis factor receptor family-related protein (GITR), and transforming growth factor beta (TGF-beta), but little is known about the exact role of Tregs in the pathogenesis of asthma. This study sought to characterize the expression of surface markers on peripheral blood mononuclear cells-derived Tregs in patients with atopic asthma and healthy subjects, and to investigate the effect of inhaled corticosteroid on them.


METHODS
The expression of surface molecules on CD4(+)CD25(high) Tregs was detected by flow cytometry. The effect of inhaled corticosteroid on expression of the surface molecules on Tregs was determined in vivo and in vitro. Total serum immunoglobulin E (IgE) and high-sensitivity C-reactive protein were measured by enzyme linked immunosorbent assay and latex enhanced immunoturbidimetric assay, respectively.


RESULTS
Equivalent numbers of peripheral Tregs were found in patients with atopic asthma (stable and acute) and healthy subjects. Tregs preferentially expressed CTLA-4, GITR, toll-like receptor 4 (TLR4), latency-associated peptide (LAP/TGF-beta1), and forkhead box P3 (FOXP3). Patients with acute asthma had decreased numbers of CD4(+)CD25(high)LAP(+) T cells compared to healthy subjects and stable asthmatics. Inhaled corticosteroid enhanced the percentage of Tregs expressing LAP in vivo and in vitro dose-dependently. Furthermore, the percentages of Tregs expressing LAP were negatively correlated with total serum IgE levels and severity of asthma, but positively correlated with forced expiratory volume in one second percentage of the predicted value in patients with asthma.


CONCLUSIONS
The results suggest that membrane-bound TGF-beta1 is a potential candidate for predicting the severity of asthma, and may contribute to the sustained remission of asthma. Strategies targeting Tregs on their surface markers, especially TGF-beta1, are promising for future therapy of asthma.
Zhang
Qian
Q
Department of Respiratory Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
Qian
Fen-hong
FH
Liu
Hua
H
Zhou
Lin-fu
LF
Huang
Mao
M
Zhang
Xi-long
XL
Yin
Kai-sheng
KS
D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000328:Adult; D015703:Antigens, CD / Q000097:blood; D000943:Antigens, Differentiation / Q000097:blood; D001249:Asthma / Q000188:drug therapy / Q000276:immunology*; D019819:Budesonide / Q000494:pharmacology; D060908:CTLA-4 Antigen; D005260:Female; D051858:Forkhead Transcription Factors / Q000097:blood; D053450:Glucocorticoid-Induced TNFR-Related Protein; D006801:Humans; D008297:Male; D008875:Middle Aged; D017475:Receptors, Nerve Growth Factor / Q000097:blood; D018124:Receptors, Tumor Necrosis Factor / Q000097:blood; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology*; D051197:Toll-Like Receptor 4 / Q000097:blood; D053773:Transforming Growth Factor beta1 / Q000097:blood
D000305:Adrenal Cortex Hormones; D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053450:Glucocorticoid-Induced TNFR-Related Protein; D017475:Receptors, Nerve Growth Factor; D018124:Receptors, Tumor Necrosis Factor; C495345:TLR4 protein, human; C491405:TNFRSF18 protein, human; D051197:Toll-Like Receptor 4; D053773:Transforming Growth Factor beta1; D019819:Budesonide