A rare population of tumor antigen-specific CD4+CD8+ double-positive ?? T lymphocytes uniquely provide CD8-independent TCR genes for engineering therapeutic T cells.
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ABSTRACT: BACKGROUND:High-affinity tumor antigen-specific T-cell receptor (TCR) gene is required to engineer potent T cells for therapeutic treatment of cancer patients. However, discovery of suitable therapeutic TCR genes is hampered by the fact that naturally occurring tumor antigen-specific TCRs are generally of low-affinity, and artificial modification of TCRs can mediate cross-reactivity to other antigens expressed in normal tissues. Here, we discovered a naturally occurring T-cell clone which expressed high-affinity HLA-A*02:01 (A*02)-restricted TCR against NY-ESO-1 from a patient who had NY-ESO-1-expressing ovarian tumor. METHODS:A*02-restricted NY-ESO-1-specific T-cell clones were established from peripheral blood of patients who had NY-ESO-1-expressing ovarian tumors. TCR ? and ? chain genes were retrovirally transduced into polyclonally activated T cells. Phenotype and function of the parental and TCR-transduced T cells were analyzed by flow cytometry, ELISA and cytotoxicity assay. In vivo therapeutic efficacy was investigated in a xenograft model using NOD/SCID/IL-2R?-deficient (NSG) mice. RESULTS:A rare population of NY-ESO-1-specific T cells, which we named 19305DP, expressed cell surface CD4, CD8?, and CD8? but not CD56 and recognized A*02+NY-ESO-1+ cancer cell lines in a CD4- and CD8-independent manner. 19305DP showed a gene expression profile that is consistent with a mixed profile of CD4+ and CD8+ single-positive T cells. Both CD4+ and CD8+ T cells that were retrovirally transduced with 19305DP-derived TCR gene (19305DP-TCR) showed strong reactivity against A*02+NY-ESO-1+ cancer cells, whereas TCR genes from the conventional A*02-restricted NY-ESO-1-specific CD8+ single-positive T-cell clones functioned only in CD8+ T cells. Both 19305DP-TCR gene-engineered CD4+ and CD8+ T cells eliminated A*02+NY-ESO-1+ tumor xenografts in NSG mice. Finally, based on reactivity against a series of alanine-substituted peptides and a panel of normal human tissue-derived primary cells, 19305DP-TCR was predicted to have no cross-reactivity against any human non-NY-ESO-1 proteins. CONCLUSION:Together, our results indicate that the naturally occurring 19305DP-TCR derived from CD4+CD8+ double-positive ?? T cells, is a promising therapeutic TCR gene for effective and safe adoptive T-cell therapy in A*02+ patients with NY-ESO-1-expressing tumor.
SUBMITTER: Matsuzaki J
PROVIDER: S-EPMC6325755 | biostudies-literature | 2019 Jan
REPOSITORIES: biostudies-literature
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