Description: The 2D10.4 monoclonal antibody reacts with human CD80 (B7-1), a 60 kDa member of the Ig superfamily. CD80 is expressed by activated B cells, macrophages and dendritic cells. In addition, activated T cells express this antigen. CD80 has high affinity for binding to two T cell surface antigens, CD28 and CD152 (CTLA-4). The interaction of CD28 and CD152 with CD80 is crucial in T-B cell communication leading to activation of T and B cells, respectively.