The quantity of peripheral regulatory T cells and the PD-1 expression in patients with coronary heart disease

Objective:To investigate the quantity of Tregs/dendritic cells(DCs) and their corresponding PD-1/PD-L1 expression,and reveal the different functional status of both Tregs and DCs in patients with stable atherosclerosis or acute coronary syndrome.Method:The 39 patients with coronary heart disease(CHD) were enrolled,including 23 stable angina(SA) patients and 16 acute coronary syndrome(ACS) patients.Twenty non-CHD individuals proved by coronary angiography were selected as controls.The quantities of CD4+CD25+CD127lowPD-1+ T cells and CD11c+PD-L1+ DCs were determined by flow cytometry.The serum levels of IL-2 were measured by ELISA.Result:There was no significant difference of Treg quantity in CHD patients(including ACS and SA patients) and healthy controls.However,we found the expression of PD-1 on Tregs and PD-L1 on DCs in ACS patients were significantly down-regulated compared with SA and controls.Conclusion:Regulatory T cells may exhibit immune suppressive function via PD-1 molecule.Impaired function of Treg and DC may promote the progress of atherosclerosis and the vulnerability of plaque.