In vitro-generated MART-1-specific CD8 T cells display a broader T-cell receptor repertoire than ex vivo naïve and tumor-infiltrating lymphocytes

Immunol Cell Biol. 2019 Apr;97(4):427-434. doi: 10.1111/imcb.12231. Epub 2019 Feb 15.


The differentiation of human hematopoietic stem cells into CD8 T cells can be achieved in vitro with the OP9-DL4 system. We considered that in the absence of medullary thymic epithelial cells, which serve to restrict the breath of the T-cell receptor (TCR) repertoire by expressing tissue-restricted antigens, a distinct repertoire would be generated in vitro. To test this notion, we compared the TCR-Vα/Vβ (TRAV/TRBV) gene usage of major histocompatibility complex-restricted antigen (MART-1)-specific T cells generated in vitro to that from ex vivo naïve T cells and tumor-infiltrating lymphocytes (TILs) using high-throughput DNA sequencing. In contrast to naïve T cells and TILs, which showed the expected narrow TRAV repertoire, in vitro-generated MART-1-specific T cells used almost all TRAV gene families and displayed unique CDR3 lengths. Our work demonstrates that the OP9-DL4 system supports the creation of a broad antigen-specific TCR repertoire, suggesting that T cells generated in vitro may undergo a different set of selection events that otherwise constrains the TCR repertoire of thymus-derived T cells.

Keywords: Antitumor T cells; T-cell development; T-cell receptor; T-cell selection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CD8-Positive T-Lymphocytes / immunology*
  • Cell Line
  • Complementarity Determining Regions / genetics
  • Hematopoietic Stem Cells / metabolism
  • Humans
  • Lymphocytes, Tumor-Infiltrating / immunology*
  • MART-1 Antigen / immunology*
  • Receptors, Antigen, T-Cell / metabolism*


  • Complementarity Determining Regions
  • MART-1 Antigen
  • Receptors, Antigen, T-Cell

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