Construction of Immunogenic Tumor Cell Surfaces by Somatic Gene Transfer

A contemporary model of T-lymphocyte activation (two-signal hypothesis) strongly suggests that in addition to recognition of peptide/MHC and, thus, tumor antigens by the T-cell antigen receptor, costimulatory signals are required for optimal T-cell clonal expansion and their differentiation into effector cells (Mueller et al. 1989; Schwartz 1990). Receptors for costimulatory signals have been identified and defined, among which CD 2, CD 11/18, CD 28, CD 4, and CD 8 appear to play important roles. Their respective ligands/coreceptors are CD 58, CD 54, CD 80/CD 86, MHC II, and MHC I, respectively.