Atherosclerosis is the major underlying pathology of cardiovascular diseases that together are the leading cause of death worldwide. The formation of atherosclerotic plaques is driven by chronic vascular inflammation. Although several risk factors have been identified and significant progress in disease prevention and treatment has been made, no therapeutic agents targeting inflammation are clinically available. Recent clinical trials established the potential of anti-inflammatory therapies as a treatment of atherosclerosis. However, adverse impacts on host defense have raised safety concerns about these therapies. Scientific evidence during the past 40 years implicated an adaptive immune response against plaque-associated autoantigens in atherogenesis. Preclinical data have underscored the protective potential of immunization against such targets precisely and without the impairment of host defense. In this review, we discuss the current vaccination strategies against atherosclerosis, supposed mechanisms of action, therapeutic potential, and the challenges that must be overcome in translating this idea into clinical practice.

Aims: Plaque erosion accounts for up to 40% of acute coronary syndromes. Unlike plaque rupture, erosion is characterized by thrombus formation on an intact fibrous cap following endothelial denudation. Rupture is associated with broad inflammatory activation, whereas erosion features accumulation of specific immune cells, particularly CD4+ and CD8+ T cells. Their functional programming remains insufficiently defined. The objective was to characterize intracoronary and peripheral T cell phenotypes, activation programs, and clonal architecture in acute coronary syndromes caused by plaque erosion compared with plaque rupture. Methods and Results: We prospectively enrolled 133 consecutive patients with acute coronary syndromes in whom plaque erosion or rupture was classified by optical coherence tomography. Blood was sampled from the coronary segment proximal to the lesion and from the peripheral circulation. T cell phenotypes were assessed by flow cytometry and plasma proteomics. In a subgroup, intracoronary samples underwent CITE-seq, integrating single-cell transcriptomics with surface protein profiling, together with paired T cell receptor sequencing. Results: Flow cytometry demonstrated enrichment of activated memory helper and cytotoxic T cells with anti-inflammatory features at erosion sites, in contrast to predominantly naive and pro-inflammatory T cells in rupture. CITE-seq revealed erosion-specific activation of pathways related to proliferation, adhesion, and tissue repair, whereas T cells in rupture displayed enhanced inflammatory pathways. Functional validation confirmed greater IL-2/IFN-γ induction in rupture-associated memory T cells and greater IL-10 induction in erosion-associated Tregs. T cell receptor sequencing showed greater clonal expansion in erosion, suggesting antigen-experienced clonal selection, whereas rupture exhibited broader and less focused clonal diversity. Conclusions: Plaque erosion and plaque rupture show fundamentally different T cell immune profiles. Erosion is marked by memory-skewed, clonally expanded regulatory and cytotoxic T cell subsets, while rupture is characterized by proinflammatory phenotypes, diverse T cell receptor repertoires, and heightened inflammatory signaling. These findings support morphology-tailored immunotherapeutic approaches, including established anti-inflammatory strategies for rupture and selective T cell-directed interventions for erosion.