Immunomodulatory properties of soluble recombinant human CD58 (LFA-3) molecules

The interaction between the E-rosette receptor (CD2) expressed on the cell surface of T lymphocytes and its natural ligand CD58 (LFA-3), a broadly distributed cell surface molecule, represents a potential target for immune modulation. To explore this possibility, we have expressed a soluble recombinant form of human CD58 which exerts potent biological effects in that it acts as a competitive inhibitor for cell surface CD58 in its binding to CD2 positive lymphocytes. Thus, recombinant CD58 blocks NK-mediated cytotoxicity, the mixed lymphocyte reaction, and the T lymphocyte adhesion to CD58 positive cells. In contrast, recombinant CD58 synergized with mitogenic CD2R monoclonal antibodies (anti-T11(2/3) or 9.1) in T cell triggering.