Sentinel lymph node macrophage (SLN macrophage)

Sentinel lymph node (SLN) macrophages and reticuloendothelial system (RES) cells are specialized immune cell populations responsible for filtering lymph and blood, respectively. SLN macrophages, particularly those located in the subcapsular sinus, serve as the primary biological target for diagnostic agents like Technetium Tc 99m tilmanocept, which is used to identify sentinel lymph nodes in patients with breast cancer or melanoma [PMID: 23460019]. These cells express high levels of the mannose receptor (CD206), a C-type lectin that facilitates the rapid internalisation of mannosylated ligands [UniProt: P22897]. RES cells, part of the broader mononuclear phagocyte system (MPS), are found in the liver (Kupffer cells), spleen, and bone marrow, where they clear particulate matter and aged erythrocytes via phagocytosis [StatPearls: Reticuloendothelial System]. While these cells are essential for immune surveillance and homeostasis, they also pose a challenge for systemic drug delivery by sequestering therapeutic nanoparticles, often requiring strategies to bypass or saturate the RES [PMID: 25607735]. Consequently, these cells are utilized both as diagnostic targets for lymphatic mapping and as key considerations in the pharmacokinetic profile of intravenously administered drugs.

Other names

Subcapsular sinus macrophageMedullary macrophageReticuloendothelial system cellMononuclear phagocyte system cellCD206-positive cell

Binding to the mannose receptor (CD206) or phagocytic uptake by cells of the mononuclear phagocyte system.