Pattern-recognition C-type lectin receptor and Mannose receptor (CLR/MR)

Pattern-recognition C-type lectin receptors (CLRs) and the Mannose receptor (MR/CD206) are a superfamily of calcium-dependent proteins that play a pivotal role in innate immunity by recognizing carbohydrate moieties on pathogens and damaged host cells (PubMed: 26336140). These receptors, primarily expressed on macrophages and dendritic cells, facilitate the internalization of antigens for processing and presentation, thereby bridging innate and adaptive immune responses (UniProt: P22897). The Mannose receptor specifically recognizes terminal mannose, fucose, and N-acetylglucosamine residues, making it a key target for mannosylated vaccine delivery systems and imaging agents like Technetium (99mTc) tilmanocept (FDA Label: Lymphoseek). In the context of oncology, CD206 is frequently used as a marker for M2-polarized tumor-associated macrophages, which are associated with immunosuppression and poor prognosis (PubMed: 30108732). Therapeutic interventions targeting these receptors aim to either stimulate immune activation for infectious diseases and cancer or inhibit pathogen entry, such as in the case of HIV or fungal infections. However, the broad expression and functional diversity of the CLR family present challenges in achieving high specificity and avoiding systemic inflammatory side effects.

Other names

CD206MRC1Macrophage mannose receptor 1C-type lectin domain familyPattern recognition receptorsPRRs

Agonism for immune stimulation, ligand-mediated targeting for imaging and drug delivery, and competitive inhibition for blocking pathogen attachment.