Background:The protective function of regulatory T cells (T
reg) has been identified in experimental atherosclerosis, but the contribution of T
regto the pathogenesis of human coronary artery disease (CAD) remains poorly understood. We investigated T
regand regulatory T-cell/effector T-cell (T
reg/T
eff) ratio in peripheral blood samples from CAD patients using a new strategy for precise identification of T
reg.
Methods and Results:Peripheral blood samples were collected from 73 stable CAD patients (55 middle-aged CAD patients and 18 old CAD patients) and 64 controls (47 middle-aged controls and 17 young controls). CD3
+CD4
+FoxP3
+T cells were divided into 3 fractions: CD45RA
+FoxP3
lowresting T
reg(Fr1), CD45RA
–FoxP3
highactivated T
reg(Fr2), and CD45RA
–FoxP3
lownon-T
reg(Fr3). CAD patients had lower percentages of Fr1 and Fr2 and higher percentages of Fr3 and CD45RA
–Foxp3
–T
eff(Fr4+5) within the CD3
+CD4
+T-cell population compared to age-matched controls. T
reg/T
effratio (Fr1+2/Fr3+4+5) in CAD patients was also markedly lower than in controls (middle-aged control, 0.17±0.09 vs. middle-aged CAD, 0.10±0.05; P<0.001). The percentage of CD4
+CD28
nullT cells within the CD4
+T-cell population was negatively correlated with T
reg/T
effratio, excluding CD4
+CD28
nullT cells <0.3% (r=–0.27, P<0.05). High-sensitivity C-reactive protein was also negatively correlated with T
reg/T
effratio (r=–0.22, P<0.05).
Conclusions:CAD patients had reduced T
regand T
reg/T
effratio compared to healthy controls. The present findings may be helpful when developing immunotherapy for the prevention of CAD. (
Circ J 2014;
78: 2935–2941)
View full abstract