T-cell receptor affinity and avidity defines antitumor response and autoimmunity in T-cell immunotherapy

Proc Natl Acad Sci U S A. 2013 Apr 23;110(17):6973-8. doi: 10.1073/pnas.1221609110. Epub 2013 Apr 1.

Abstract

T cells expressing antigen-specific T-cell receptors (TCRs) can mediate effective tumor regression, but they often also are accompanied by autoimmune responses. To determine the TCR affinity threshold defining the optimal balance between effective antitumor activity and autoimmunity in vivo, we used a unique self-antigen system comprising seven human melanoma gp100(209-217)-specific TCRs spanning physiological affinities (1-100 μM). We found that in vitro and in vivo T-cell responses are determined by TCR affinity, except in one case that was compensated by substantial CD8 involvement. Strikingly, we found that T-cell antitumor activity and autoimmunity are closely coupled but plateau at a defined TCR affinity of 10 µM, likely due to diminished contribution of TCR affinity to avidity above the threshold. Together, these results suggest that a relatively low-affinity threshold is necessary for the immune system to avoid self-damage, given the close relationship between antitumor activity and autoimmunity. The low threshold, in turn, indicates that adoptive T-cell therapy treatment strategies using in vitro-generated high-affinity TCRs do not necessarily improve efficacy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Autoimmunity / immunology*
  • Cytotoxicity Tests, Immunologic
  • Enzyme-Linked Immunosorbent Assay
  • Fluorescence
  • Humans
  • Immunohistochemistry
  • Immunotherapy, Adoptive / methods*
  • Neoplasms / immunology*
  • Neoplasms / therapy*
  • Receptors, Antigen, T-Cell / metabolism*
  • Transduction, Genetic
  • gp100 Melanoma Antigen / immunology

Substances

  • Receptors, Antigen, T-Cell
  • gp100 Melanoma Antigen