Figure 1

A new working model: Regulatory T cells and immunosuppressive/anti-inflammatory cytokines inhibit endothelial dysfunction. In physiological status, the interaction between endothelium-dependent vasoconstrictors (including Ang II, ET-1, ROS) and vasodilators (NO, EDHF and PGI2) maintain the endothelial function and equilibrium of vascular tone. The impairment of the balance between the vasoconstrictors and vasodilators is generally defined as the endothelial dysfunction. Under cardiovascular diseases risk factors stimuli, when vasodilation pathways being impaired or vasoconstriction being activated, endothelial dysfunction occurs. Regulatory T cells (Tregs) act on endothelial cells via cell-cell-interaction and/or immunosuppressive/antiinflammatory cytokines to inhibit endothelial dysfunction and restore normal vascular tone.