Anti-Human CD2 (LO-CD2a) - Purified <i>in vivo</i> GOLD^TM Functional Grade (C509-GRP)

Human CD2 is a 351 amino acid transmembrane glycoprotein that is part of the immunoglobulin superfamily1, 2. CD2 is expressed on the surface of mature T cells, most NK cells, thymocytes, dendritic cells, and 9-12% of bone marrow cells. CD2 participates in T cell and NK cell activation and is important for thymocyte development and assembly of the immunological synapse1. However, the role of CD2 in murine immunity is not always consistent with its function in higher animals. CD2 is known to bind to lymphocyte-associated antigen3 (CD58 and its murine analog CD48) as well as CD59. LO-CD2a was developed as an immunosuppressive agent for use in organ allotransplantation3, 4. LO-CD2a strongly inhibits mixed lymphocyte culture3 and induces T cell apoptosis5. Additionally, LO-CD2a induces very low levels of cytokine release, inhibits cytokine production induced by OKT3, and induces human T cell hyporesponsiveness3. The immune response is inhibited as a result of cell lysis by antibody-dependent cell mediated cytotoxicity (ADCC) induced by NK cells and activated monocytes and from CD2 down-modulation on CD2+ cells6. LO-CD2a also strongly inhibits proliferation of peripheral blood mononuclear cells stimulated with soluble OKT3. LO-CD2a has demonstrated immunosuppressive activity in vitro and effective T cell depletion in vivo. Unresponsiveness upon restimulation with the same antigen makes LO-CD2 distinct from other anti-CD2 antibodies7.