Macrophages are white blood cells that engulf and digest cellular debris, foreign substances, microbes, and cancer cells. CD206 is a specific protein on the surface of some macrophages, a marker for their diverse functions. Its presence indicates a particular functional state.
The Role of CD206 on Macrophages
CD206, also known as the Mannose Receptor (MR), is a pattern recognition receptor. It identifies and binds to carbohydrate structures found on pathogens.
Once bound, CD206 facilitates endocytosis internalization. It clears pathogens, cellular debris, and modified self-components. The receptor also contributes to antigen presentation, aiding immune recognition and response.
The mannose receptor scavenges. It binds to and internalizes host-derived molecules, maintaining tissue cleanliness and processing biological waste products.
CD206 as a Marker for Macrophage Types
Macrophages exhibit plasticity, adapting functions and polarizing. CD206 is a marker for “M2” or “alternatively activated” macrophages. M2 macrophages function distinctly from M1 macrophages.
M2 macrophages are associated with anti-inflammatory responses, promoting inflammation resolution and tissue repair. They regulate immunity, dampening reactions and maintaining immune balance. While M1 macrophages are pro-inflammatory and clear pathogens, M2 macrophages focus on healing and immune suppression.
CD206 expression identifies and helps study M2-like macrophage populations. It indicates a macrophage phenotype involved in tissue remodeling, angiogenesis, and immune suppression. It helps differentiate macrophage roles in health and disease.
CD206 Macrophages in Health
CD206-expressing macrophages maintain balance. In wound healing, they clear cellular debris and dead cells. They release growth factors promoting tissue regeneration.
These macrophages contribute to resolving inflammation. They switch off pro-inflammatory signals and produce anti-inflammatory mediators, restoring tissue equilibrium. This prevents excessive immune responses.
Beyond injury repair, CD206 macrophages support tissue homeostasis. They monitor tissues, removing apoptotic cells and maintaining organ integrity. Their presence ensures orderly cell turnover and efficient recycling of biological components.
CD206 Macrophages in Disease
While beneficial in health, CD206-expressing macrophages are detrimental in disease. In tumor progression, these macrophages are often recruited to tumors as tumor-associated macrophages (TAMs). TAMs can promote tumor growth by fostering angiogenesis, suppressing anti-tumor immunity, and facilitating cancer cell invasion and metastasis.
In chronic inflammatory conditions, such as fibrosis, CD206 macrophages contribute to disease pathology. They secrete factors stimulating excessive collagen deposition, leading to scar tissue and impaired organ function. This persistent pro-fibrotic activity can worsen the disease outcome.
In certain infectious diseases, CD206 macrophages contribute to pathogen persistence or disease severity. Some pathogens, like Mycobacterium tuberculosis, exploit CD206’s endocytic capabilities to enter macrophages and establish a replication niche, evading immune clearance. Their presence can exacerbate the disease rather than resolve it.
References
All about the Mannose Receptor CD206. Available at: https://www.antibodies.com/mannose-receptor-cd206-antibody. Last accessed on July 31, 2025.
The Macrophage: Plasticity, Polarization, and Pathogenesis. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3839209/. Last accessed on July 31, 2025.
Macrophages in Wound Healing. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5530756/. Last accessed on July 31, 2025.
Tumor-associated macrophages: a paradigm of macrophage plasticity and diversity. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7211119/. Last accessed on July 31, 2025.