Preclinical assessment of transiently TCR redirected T cells for solid tumour immunotherapy

Cancer Immunol Immunother. 2019 Aug;68(8):1235-1243. doi: 10.1007/s00262-019-02356-2. Epub 2019 Jun 18.


Off-target toxicity due to the expression of target antigens in normal tissue or TCR cross-reactivity represents a major risk when using T cell receptor (TCR)-engineered T cells for treatment of solid tumours. Due to the inherent cross-reactivity of TCRs it is difficult to accurately predict their target recognition pre-clinically. It has become evident that direct testing in a human being represents the best evaluation of the risks. There is, therefore, a clear unmet need for assessing the safety of a therapeutic TCR in a more controllable manner than by the injection of permanently modified cellular products. Using transiently modified T cells combined with dose escalation has already been shown feasible for chimeric antigen receptor (CAR)-engineered T cells, but nothing is yet reported for TCR. We performed a preclinical evaluation of a therapeutic TCR transiently expressed in T cells by mRNA electroporation. We analyzed if the construct was active in vitro, how long it was detectable for and if this expression format was adapted to in vivo efficacy assessment. Our data demonstrate the potential of mRNA engineered T cells, although less powerful than permanent redirection, to induce a significant response. Thus, these findings support the development of mRNA based TCR-therapy strategies as a feasible and efficacious method for evaluating TCR safety and efficacy in first-in-man testing.

Keywords: Immunotherapy; In vivo model; Solid tumour; T cell receptor; mRNA.

MeSH terms

  • Animals
  • Cancer Vaccines / immunology*
  • Colorectal Neoplasms / immunology
  • Colorectal Neoplasms / therapy*
  • Cross Reactions
  • Cytotoxicity, Immunologic
  • Electroporation
  • HCT116 Cells
  • Humans
  • Immunotherapy, Adoptive / methods*
  • Mice
  • Mice, SCID
  • Neoplasms, Experimental
  • RNA, Messenger / genetics
  • Receptors, Chimeric Antigen / genetics
  • Receptors, Chimeric Antigen / metabolism*
  • T-Cell Antigen Receptor Specificity
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / transplantation
  • Xenograft Model Antitumor Assays


  • Cancer Vaccines
  • RNA, Messenger
  • Receptors, Chimeric Antigen