First Author | Uram JN | Year | 2011 |
Journal | J Immunol | Volume | 186 |
Issue | 7 | Pages | 3847-57 |
PubMed ID | 21346233 | Mgi Jnum | J:170836 |
Mgi Id | MGI:4947465 | Doi | 10.4049/jimmunol.1000361 |
Citation | Uram JN, et al. (2011) Nondominant CD8 T cells are active players in the vaccine-induced antitumor immune response. J Immunol 186(7):3847-57 |
abstractText | We previously reported that CD8(+) T cells are directed predominantly toward the immunodominant Her-2/neu (neu) epitope RNEU(420-429) in nontolerized FVB/N but not tolerized HER-2/neu (neu-N) mice. In this study, we screened overlapping peptides of the entire neu protein and identified six new epitopes recognized by vaccine-induced neu-N-derived T cells. Evaluation of individual nondominant responses by tetramer staining and IFN-gamma secretion demonstrate that this repertoire is peripherally tolerized. To address the role that the complete CD8(+) T cell repertoire plays in vaccine-induced antitumor immunity, we created a whole-cell vaccine-expressing neu cDNA that has been mutated at the RNEU(420-429) anchor residue, thereby abrogating activation of immunodominant epitope responses. Studies comparing the mutated and nonmutated vaccines indicate that nondominant CD8(+) T cells can induce antitumor immunity when combined with regulatory T cell-depleting agents in both neu-N and FVB/N mice. Collectively, these studies demonstrate that the neu-directed T cell repertoire is not intrinsically incapable of eradicating tumors. Rather, they are suppressed by mechanisms of peripheral tolerance. Thus, these studies provide new insights into the function of the complete T cell repertoire directed toward a clinically relevant tumor Ag in tumor-bearing hosts. |