Anti-Human MUC1 (CD227) - Purified (M461-GRP)

MUC1 is a large, highly glycosylated transmembrane mucin which contains a very large extracellular domain of 1000-2200 amino acids consisting primarily of 20 amino acid tandem repeats 1. MUC1 is a member of a family of related cell surface epithelial mucins 1,2 and is structurally related to hemopoietic and endothelial sialomucins such as GlyCAM1 and MadCAM-1 2. MUC1 forms part of the mucous gel that covers the external surface of epithelial tissues and acts as a barrier to infection 1. Additionally, MUC1 is involved in signal transduction via its highly conserved cytoplasmic tail, which is tyrosine phosphorylated in activated dendritic cells and T cells 2, and binds all members of the ErbB family of receptor tyrosine kinases as well as β-catenin 1. Additionally, there is interest in using MUC1 as a target antigen for cancer immunotherapy for carcinomas and multiple myeloma 2, due to variations in glycosylation that can be present in cancer 1. HMFG2 was generated by immunizing BALB/c mice with delipidated human milk fat globule (HMFG) containing the intact mucin, and subsequently immunizing with mammary epithelial cells 3. Spleen cells were fused with myeloma line P3/NSl/l-Ag4-1 to create hybridomas, which were screened for specificity against epithelial cells. HMFG2 reacts with an underglycosylated MUC1 mucin 4 and recognizes oligosaccharide sequences containing galactose, N-acetyl glucosamine and N-acetyl galactosamine, specifically the DTR sequence of the core protein 5. Binding to the core-protein epitopes is influenced by the length of the carbohydrate side chains 6.