Macrophages in health and disease

Area of Science:

• Immunology
• Cell Biology
• Tissue Homeostasis

Background:

• Tissue macrophages exhibit significant heterogeneity in both healthy and diseased states.
• Recent advancements have generated extensive data on macrophage diversity, necessitating a structured understanding.
• Existing frameworks often focus on primary origin (embryonic or bone marrow), overlooking critical developmental and environmental factors.

Purpose of the Study:

• To propose a conceptual framework for understanding macrophage heterogeneity.
• To emphasize the importance of macrophage ontogeny, encompassing origin, differentiation, and environmental influences.
• To provide a basis for organizing and interpreting data on macrophage origins and functions.

Main Methods:

• Conceptual analysis and synthesis of existing literature on macrophage biology.
• Development of a novel framework integrating ontogeny with macrophage function.
• Review of data concerning embryonic vs. bone marrow derivation and differentiation pathways.

Main Results:

• Macrophage ontogeny, defined by origin, differentiation course, and environmental cues (steady-state and disease-associated signals) over time, is a critical determinant of function.
• This comprehensive view of ontogeny is essential for understanding macrophage contributions to tissue homeostasis and disease progression.
• A proposed framework facilitates a more organized and insightful approach to studying macrophage heterogeneity.

Conclusions:

• Macrophage ontogeny is a more encompassing concept than previously appreciated, crucial for understanding their roles.
• Integrating origin, differentiation, and environmental context provides a robust framework for macrophage research.
• This conceptual model will advance our understanding of how macrophages impact health and disease.