Human CD58/LFA-3 Alexa Fluor™ Plus 680-conjugated Antibody

T cells require a signal induced by the engagement of the T cell receptor and a “co-stimulatory” signal(s) through distinct T cell surface molecules for optimal T cell expansion and activation. Many cell-bound receptor-ligand pairs have now been shown to be involved in T cell co-stimulation including CD58/CD2 in humans and CD48/CD2 in mice and rats. CD58, also known as lymphocyte function-associated antigen (LFA-3), is a 210 amino acid protein that belongs to the CD2 family of the immunoglobulin superfamily (1). CD58 is widely expressed on hematopoietic and non-hematopoietic human tissue and has been found on leukocytes, erythrocytes, endothelial cells, epithelial cells and fibroblasts of human origin (2). No mouse or rat homolog of CD58 has as of yet been identified. CD58 has only one known ligand, CD2. CD2 is expressed on T cells, NK cells and dendritic cells (2-4). CD2 ligation by CD58 has been shown to mediate T cell adhesion, T cell activation, T cell cytokine production, and T cell and NK cells cytotoxic activity (1, 3, 5, 6). In dendritic cells, CD2 engagement increases MHC Class II, CD40, CD80, CD86, CD58, and CCR7 and induces IL-1 beta and IL-12 cytokine secretion (4).