Chemokine receptor CCR5 is upregulated in the regulatory T cells (Tregs) and monocytic-myeloid-derived suppressor cells (M-MDSCs) of young dyslipidemic individuals. In this study, we investigated the role of CCR5 in regulating the phenotypic and functional plasticity of Tregs and M-MDSCs during the preclinical phase of atherosclerosis. Inflammatory conditions induce a phenotypic shift in Tregs and M-MDSCs, characterised by enhanced expression of CCR5 and pro-inflammatory cytokines. Tregs from dyslipidemic (DLP) and coronary artery disease (CAD) patients exhibited a mixed Th1/Th17/Treg phenotype, whilst M-MDSCs displayed elevated markers of activation and inflammation. CCR5 inhibition via DAPTA (10