Tissue-resident macrophages, the mighty guardians of the immune system, assume an indispensable role in the orchestration of tissue homeostasis and immune responses, acting as vigilant sentinels in the intricate battlefield of cellular immunity.

Here, Creative Biolabs shares some basic information about tissue-resident macrophages, exploring their origins and development, diverse phenotypes and functions, examples in different tissues, and their significance in disease pathogenesis and therapeutic potential. We also provide high-quality human/murine macrophage isolation and culture services and facilitate meaningful macrophage project development.

Origins and Development of Tissue-Resident Macrophages

Tissue-resident macrophages arise from distinct embryonic and adult hematopoietic precursors.

Fig. 1 Fetal macrophage development. (Wu Y and Hirschi K K, 2021)

• During embryogenesis, macrophages originate from the yolk sac and fetal liver, colonizing various tissues during early development.
• In contrast, adult tissue-resident macrophages are predominantly derived from circulating monocytes that infiltrate tissues and differentiate into specialized macrophages.

The mechanisms governing their development are regulated by a complex interplay of transcription factors and local tissue cues, ultimately shaping their unique phenotypes and functions.

Distinct Phenotypes and Functions of Tissue-Resident Macrophages

Tissue-resident macrophages exhibit remarkable heterogeneity in their phenotypes and functions. These cells adapt to the specific needs of their tissue microenvironment, displaying distinct gene expression profiles and functional characteristics.

• In the central nervous system, microglia act as resident macrophages, contributing to neurodevelopment, synaptic plasticity, and immune surveillance. They are involved in the clearance of apoptotic cells, synaptic pruning, and the regulation of neuroinflammation.
• Alveolar macrophages in the lungs are specialized in maintaining pulmonary homeostasis and defending against inhaled pathogens. They maintain lung homeostasis by removing debris and participate in immune surveillance within the airways.
• Liver Kupffer cells, these macrophages reside in the liver and play a crucial role in liver health and function. Kupffer cells are responsible for the phagocytosis of senescent red blood cells, clearance of pathogens from the bloodstream, and regulation of hepatic inflammation.
• The spleen houses red pulp macrophages, which are involved in erythrocyte clearance and immune surveillance.
• In the skeletal system, osteoclasts are derived from macrophage precursors and regulate bone remodeling. They participate in bone remodeling, repair, and regeneration processes.
• Adipose tissue harbors resident macrophages that participate in metabolic regulation and adipose tissue homeostasis.
• Langerhans cells, these macrophages are located in the epidermis of the skin and act as sentinels for detecting and responding to pathogens.

If you are interested in macrophage identification service, please feel free to contact us and further discuss it with our scientists.

Importance in Disease and Therapeutic Potential

The intricate involvement of tissue-resident macrophages in disease pathogenesis is increasingly recognized. Dysregulation of macrophage phenotypes and functions can contribute to the development and progression of numerous diseases, including cancer, autoimmune disorders, and chronic inflammation. Consequently, targeting tissue-resident macrophages has emerged as a promising therapeutic strategy.

• Macrophage repolarization
• Immune checkpoint modulation
• Nanotechnology-based interventions

These approaches hold great potential in harnessing the immunomodulatory properties of tissue-resident macrophages for therapeutic benefits.

Tissue-resident macrophages stand as key players in maintaining tissue homeostasis, immune regulation, and disease pathology. Creative Biolabs remains at the forefront of this field, dedicated to unlocking the full potential of tissue-resident macrophages. For more details about our services, please feel free to contact us.

References

1. Davies L C and Taylor P R. Tissue-resident macrophages: then and now. Immunology, 2015, 144(4): 541-548.
2. Wu Y and Hirschi K K. Tissue-resident macrophage development and function. Frontiers in Cell and Developmental Biology, 2021, 8: 617879.