CD206: a potential candidate for targeted delivery of therapeutics

Macrophage mannose receptor 1 (MRC1), also known as CD206, is a Pattern Recognition Receptor (PRR). PRRs are expressed by antigen processing and presentation cells, and are activated upon detection of Pathogen-Associated Molecular Patterns (PAMPs). PAMPs are molecular sequences shared by large groups of pathogens, which are essential for microbial survival and/or pathogenicity and include cell wall components such as glycoproteins. Many glycoproteins derived from bacteria and fungi are mannosylated, and CD206 is specifically involved in the recognition of these molecules, resulting in endocytosis of the micro-organisms which express them.

CD206 is a type I transmembrane protein that belongs to the C-type lectin family, and is expressed by macrophages and dendritic cells (1). Macrophages can be classified as being of an M1 or M2 phenotype. M1 macrophages promote a Th1 response, have pro-inflammatory and cytotoxic properties, and can eradicate intracellular pathogens. M2 macrophages promote a Th2 response, display anti-inflammatory properties, and are implicated in tissue repair (2). CD206 is expressed on M2 macrophages (3).

Immunohistochemistry-Paraffin: CD206 Antibody

Macrophage activity has been implicated in a number of diseases, including cancer and rheumatoid arthritis, and as such macrophages represent a potential therapeutic target. Yu et al have used mannosylated nanoparticles to directly compare the delivery of siRNA to immortalised macrophages and to cancer cell lines, demonstrating a novel method of selectively targeting the CD206 positive cells (4). Since CD206 shows high expression levels in disease sites such as the tumour micro-environment, strategies that optimise the uptake of therapeutics by cells in these regions have the potential to be extremely powerful (5). Furthermore, this directed uptake is likely to require smaller doses, thereby reducing the toxicity of the delivered substances.

Novus Biologicals offers CD206 reagents for your research needs including:

PMIDs