Detection And Significance Of Regulatory CD4~+CD25~+T Cells In Peripheral Blood Of Acute Coronary Syndromes

Objectives To investigate peripheral numbers and function of CD4+CD25+regulatory T cell in peripheral blood of patients with acute coronary syndromes and to indentify the relationship between the abnormality in peripheral numbers and function of Tregs and ACS.Methods Frequencies of CD4+CD25+ regulatory T cells in peripheral blood were detected in 28 patients with ACS ,26 patients with stable angina and 30 normal individuals by flow cytometry employing labelled antibodies to CD4 and CD25. Functional suppressive properties of Tregs were assayed by establishing a triple-cell culture in which purified Tregs were incubated with 150Gy irradiated peripheral blood mononuclear cells(antigen-presenting cells) and anti-CD3-activated responder T cells. Meanwhile Before the culture termination ,we removed 100μl supernatant,then measured levels of IL-10 and TNF-αin supernatant and circulation by ELISA. The levels of CRP and blood-fat were detected routinely.Results The frequencies of CD4+CD25+regulatory T cells in peripheral blood in ACS group were significantly decreased compared to the SAP group and controls (all P<0.05). Tregs in ACS patients were significantly compromised as their ability to suppress responder CD4+CD25-Tcell proliferation was attenuated.Conclusion In patients with ACS, naturally occurring CD4+CD25+ Treg numbers are reduced and their functional properties compromised. The decrease in frequencies and function of Tregs may break the balance of peripheral immunotolerance and induce to activation of associatied-T cells and inflammatory reaction. These findings may aid in understanding the pathological mechanisms leading to the development of atherosclerosis.