Macrophages overexpressing interleukin-10 target and prevent atherosclerosis: regression of plaque formation and reduction in necrotic core

Abstract Background Atherosclerosis, a slowly progressing inflammatory disease, is characterized by the presence of monocyte-derived macrophages. Interventions targeting the inflammatory characteristics of atherosclerosis hold promising potential. Although interleukin (IL)-10 is widely acknowledged for its anti-inflammatory effects, systemic administration of IL-10 has limitations due to its short half-life and significant systemic side effects. Purpose We aimed to investigate the effectiveness of an approach designed to overexpress IL-10 in macrophages and subsequently introduce these genetically modified cells into ApoE-/- mice to promote atherosclerosis regression. Methods We engineered RAW264.7 cells to overexpress IL-10 (referred to as IL-10M) using lentivirusvectors. The ApoE-/- mice were divided into two groups based on the timing of the intervention. The early intervention group (n = 45) received intravenous tail injections from the beginning of Western diet (WD) at six weeks old. The late intervention group (n = 45) started receiving injections at 16 weeks old, 2 months after being fed the WD. Both the early and late intervention group stopped receiving injections after 5 months of being fed the WD. Results The IL-10M exhibited robust IL-10 secretion, maintained phagocytic function, improved mitochondrial membrane potentials, reduced superoxide production and showed a tendency toward the M2 phenotype when exposed to inflammatory stimuli. IL-10M can selectively target plaques in ApoE-/- mice, and oil red staining of the entire aorta unequivocally demonstrated that intervention with IL-10M elicited a substantial reduction in plaque area. H&E staining revealed that mice treated with IL-10M in the early intervention group showed a significant reduction in the ratio of plaque area to lumen area. However, the late intervention group did not exhibit statistically significant differences. Notably, mice treated with IL-10M exhibited significantly smaller necrotic cores and reduction in matrix metalloproteinase 9 within the aortic plaques in both the early and late intervention groups. Additionally, the administration of IL-10M showed no obvious side effects. Conclusion We developed an anti-inflammatory protein delivery system based on engineered macrophages that can target atherosclerotic plaques and reduce the plaque area and necrotic core. This approach has a promising safety profile and has the potential to be a therapeutic strategy for the intervention of atherosclerosis.