Attacking Atherosclerosis from Within: Immunotherapy Takes Aim at the Most Dangerous Cells in Artery Walls
Arterial plaque is the silent engine behind most heart attacks and strokes. A new study in Science describes a targeted immunotherapy that identifies and attacks the most dangerous cells in atherosclerotic plaques, using a protein normally deployed only in cancer treatment.
Atherosclerosis starts quietly: fatty particles accumulate in artery walls, the immune system responds, and a plaque slowly forms. For decades, that plaque was viewed mainly as a passive buildup of cholesterol and dead cells. In recent years, however, it has become clear that plaque is a dynamic cellular ecosystem, and that some of the cells living inside it are far more dangerous than others.
The study, published in Science, focuses on one specific subgroup: modulated vascular smooth muscle cells. Under normal circumstances, these cells keep artery walls supple and strong. In atherosclerosis, some of them shift into a different state, becoming less stable, pro-inflammatory, and difficult to distinguish from macrophages, the immune cells that populate the plaque. This transformation makes plaques vulnerable to rupture, which triggers the sudden blood clots that cause heart attacks.
FAP: a cancer protein as a Trojan horse
The researchers discovered that these dangerous, transformed muscle cells express a protein known as FAP, fibroblast activation protein. FAP is not a new target: oncologists have been working with it for years as a way to attack tumor stroma. The fact that the same marker turns up in atherosclerotic plaques opened an unexpected therapeutic avenue. The researchers tested FAP-targeted immunotherapy in mouse models and found that plaques became more stable: fewer transformed smooth muscle cells, less inflammation, and a structurally more robust artery wall.
The idea of repurposing oncological immunotherapy for cardiovascular disease is relatively new. Heart disease and cancer are typically treated as separate domains, yet they share more cellular mechanisms than was long assumed. Cells that transform, behave as something other than what they are, and drive inflammatory processes, that pattern shows up in both conditions.
What this means for aging
Atherosclerosis is, at its core, a disease of aging. Prevalence rises sharply with age, and most fatal cardiovascular events strike people over sixty. By identifying a cell type that contributes to plaque destabilization, this study opens new possibilities for early intervention, going beyond lowering cholesterol or blood pressure to targeting the cellular transformation processes that make plaques dangerous in the first place.
For now, the results are in mice. Whether FAP expression in human plaques plays the same role, and whether the therapy is safe enough to test in people, are the questions that come next. But the conceptual shift itself, from plaques as static accumulations to dynamic cellular populations that can be selectively targeted, already carries fundamental significance for the field.