Recombinant Mouse CD52 Fc Chimera Protein, CF

CD52, also known as CAMPATH-1 antigen, HE5, and gp20, is a cell surface glycoprotein that can be targeted to induce immune suppression by complement-mediated cell lysis (1, 2). Mature mouse CD52 is a short peptide that is tethered to the cell surface with a GPI linkage (1, 2). CD52 carries a large N-linked carbohydrate moiety which increases the molecular weight significantly (3-5). Mouse CD52 shares only 23% and 16% amino acid identity with rat and human CD52, respectively. CD52 is expressed on lymphocytes, monocytes, monocycte-derived dendritic cells, eosinophils, and neutrophils (6-8), as well as on mature spermatozoa and epithelial cells lining the male genital tract (5, 9, 10). It protects sperm against anti-sperm antibodies by binding to C1q and inhibiting complement activation (11). CD52 ligation on CD4+ T cells induces a suppressive population of cells that release soluble CD52 which then binds to Siglec-10 (12-14). This interaction inhibits the proliferation of activated T cells and the cytotoxic function of autoimmune CD8+ T cells in type 1 diabetes (13).