Lymphatic system macrophages

Lymphatic system macrophages are a heterogeneous population of myeloid cells located within the lymph nodes, including subcapsular sinus (SSM), medullary sinus (MSM), and medullary cord macrophages (MCM). These cells function as a vital biological filter, capturing lymph-borne antigens, viruses, and bacteria to prevent systemic dissemination (Martinez-Pomares & Gordon, 2012, Trends in Immunology). They play a crucial role in the initiation of adaptive immunity by presenting captured antigens to B and T lymphocytes. In oncology, SSMs can limit tumor progression by sequestering tumor-derived extracellular vesicles, but they may also be subverted to promote a pro-metastatic environment (Bernhard et al., 2021, Nature Communications). Although they are a cellular population rather than a single protein, they are targeted by diagnostic agents like Technetium Tc 99m tilmanocept, which binds the mannose receptor (CD206) to map sentinel lymph nodes (Wallace et al., 2003, Journal of Nuclear Medicine). Therapeutic strategies explore modulating these macrophages to improve vaccine responses or to deliver anti-inflammatory payloads in autoimmune diseases (Gordon & Plüddemann, 2017, BMC Biology). Their strategic location makes them ideal targets for nanoparticle-based drug delivery systems aimed at the lymphatic system.

Other names

Lymph node macrophagesSubcapsular sinus macrophagesMedullary sinus macrophagesMedullary cord macrophagesSinusoidal macrophages

Receptor-mediated binding and uptake by macrophage-specific surface proteins, such as the mannose receptor (CD206), for diagnostic imaging or therapeutic delivery (Wallace et al., 2003, Journal of Nuclear Medicine).