Wandering Macrophages: Functions in Immunity and Tissue Repair

Wandering macrophages (free macrophages/histiocytes) are motile white blood cells in connective tissue and serosal cavities, derived from blood monocytes. They extend pseudopodia to move through tissues.

Key Functions

1. Phagocytosis: Engulf and digest pathogens, debris, dead cells—critical for infection defense and clearance.
2. Antigen presentation: Process and present antigens to T cells, activating adaptive immunity and immunological memory.
3. Cytokine secretion: Release signaling molecules that recruit neutrophils/monocytes and direct T-cell differentiation.
4. Tissue repair: Release growth factors promoting angiogenesis and fibroblast proliferation for collagen production.
5. Homeostasis: Clear cellular waste, maintaining tissue health.

Overall, wandering macrophages are essential for defense, repair, and tissue homeostasis.