An altered gp100 peptide ligand with decreased binding by TCR and CD8 alpha dissects T cell cytotoxicity from production of cytokines and activation of NFAT

作者：Schaft Niels^*; Coccoris Miriam; Drexhage Joost; Knoop Christiaan; de Vries I Jolanda M; Adema Gosse J; Debets Reno

来源：Frontiers in Immunology, 2013, 4: UNSP 270.

DOI：10.3389/fimmu.2013.00270

• activation of nuclear factor of a ctivatedT cells
• altered peptide ligands
• cytokine production
• cytotoxicity
• human T lymphocytes
• T cell receptor

Altered peptide ligands (APLs) provide useful tools to study T cell activation and potentially direct immune responses to improve treatment of cancer patients. To better understand and exploit APLs, we studied the relationship between APLs and T cell function in more detail. Here, we tested a broad panel of gp100(280-288) APLs with respect to T cell cytotoxicity, production of cytokines, and activation of Nuclear Factor of Activated T cells (NEAT) by human T cells gene-engineered with a gp100-HLA-A2-specificTCR alpha beta. We demonstrated that gp100-specific cytotoxicity, production of cytokines, and activation of NEAT were not affected by APLs with single amino acid substitutions, except for an APL with an amino acid substitution at position 3 (APL A3), which did not elicit any T cell response. A gp100 peptide with a double amino acid mutation (APL S4S6) elicited T cell cytotoxicity and production of IFN gamma, and to a lesser extentINF alpha, 1154, and 1155, but not production of 1152 and 11,10, or activation of NEAT Notably, T cell receptor (TCR)-mediated functions showed decreases in sensitivities for S4S6 versus gp100 wild-type (wt) peptide, which were minor for cytotoxicity but at least a 1000-fold more prominent for the production of cytokines. TCR-engineered T cells did not bind A3-HLA-A2, but did bind S4S6-HLA-A2 although to a lowered extent compared to wt peptide-HLA-A2. Moreover, S4S6-induced T cell function demonstrated an enhanced dependency on CD8 alpha. Taken together, most gp100APLs functioned as agonists, butA3 and S4S6 peptides acted as a null ligand and partial agonist, respectively. Our results further suggest that TCR-mediated cytotoxicity can be dissected from production of cytokines and activation of NEAT and that the agonist potential of peptide mutants relates to the extent of binding by TCR and CD8 alpha. These findings may facilitate the design of APLs to advance the study of T cell activation and their use for therapeutic applications.

• 出版日期2013