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

Area of Science:

• Immunology
• Cell Biology
• Biochemistry

Background:

• Macrophages (MΦs) are key immune cells involved in immune response and tissue homeostasis.
• Assessing MΦ polarization (M1/M2) and metabolic state is vital for immune status evaluation.
• Conventional flow cytometry uses extrinsic labels that can affect cellular function.

Purpose of the Study:

• To investigate changes in macrophage autofluorescence (AF) profiles under various activation and stress conditions.
• To evaluate the potential of AF as a non-invasive method for immune cell phenotyping.
• To assess AF for distinguishing atherosclerosis patients from healthy individuals.

Main Methods:

• Multispectral flow cytometry was used to analyze AF profiles of human monocyte-derived macrophages.
• Macrophages were subjected to M1/M2 polarization, hypoxia, starvation, and interaction with low-density lipoproteins.
• AF profiles from clinical leukocyte samples were analyzed using advanced predictive models.

Main Results:

• Macrophage AF profiles varied distinctly under different polarization and stress conditions.
• Leukocyte AF profiles differentiated atherosclerosis patients from healthy controls with high accuracy (ROC-AUC of 0.84 ± 0.09).
• AF analysis demonstrated sensitivity in reflecting macrophage activation and metabolic states.

Conclusions:

• Macrophage autofluorescence is a sensitive, non-invasive indicator of cellular activation and metabolic status.
• AF analysis offers a promising tool for immune cell phenotyping.
• AF holds potential for clinical applications, particularly in atherosclerosis diagnostics.