Autofluorescence Flow Cytometry for Macrophages Analysis: Polarization, Stress Conditions, and Atherosclerosis Model

Macrophages (MΦs) are integral cellular components responsible for immune response and tissue homeostasis. Evaluation of their pro-inflammatory (M1) and anti-inflammatory (M2) polarization states, along with their metabolic profiles, typically conducted via flow cytometry, is crucial for assessing the immune status of an organism. Traditional flow cytometry relies on extrinsic fluorescent labels, which may interfere with cellular function. Here, using multispectral flow cytometry, we demonstrate how the autofluorescence profiles of human monocyte-derived macrophages change under M1/M2 polarization, hypoxia and starvation stress factors, and interaction with low-density lipoproteins as an atherosclerosis model. Extending these findings to clinical samples, we demonstrated that leukocyte AF profiles could distinguish atherosclerosis patients from healthy controls with a ROC-AUC of 0.84 ± 0.09, advanced predictive models. These findings highlight AF as a sensitive, non-invasive tool for assessing macrophage activation and metabolic states, with potential applications in atherosclerosis diagnostics and immune cell phenotyping.