Interferon-gamma-induced intercellular adhesion molecule-1: expression on human tumor cells enhances bifunctional antibody-mediated lysis through a lymphocyte function-associated antigen-1 dependent mechanism.

Antitumor x anti-CD3 bifunctional antibodies (BFAs) affect tumor cell lysis by activating and physically linking T-cells and tumor cells. Since tumor target antigen expression does not correlate with susceptibility to BFA-mediated tumor cytotoxicity, we investigated the role of cell adhesion molecules as accessory molecules. In 3 human colon tumor cell lines (LS174T, WIDR, and COLO205), recombinant interferon-gamma (rIFN-gamma) consistently increased BFA-mediated tumor cell lysis by cultured peripheral blood lymphocytes and consistently increased tumor cell expression of intercellular adhesion molecule-1 (ICAM-1).