Imaging activated T cells predicts response to cancer vaccines

J Clin Invest. 2018 Jun 1;128(6):2569-2580. doi: 10.1172/JCI98509. Epub 2018 May 14.


In situ cancer vaccines are under active clinical investigation, given their reported ability to eradicate both local and disseminated malignancies. Intratumoral vaccine administration is thought to activate a T cell-mediated immune response, which begins in the treated tumor and cascades systemically. In this study, we describe a PET tracer (64Cu-DOTA-AbOX40) that enabled noninvasive and longitudinal imaging of OX40, a cell-surface marker of T cell activation. We report the spatiotemporal dynamics of T cell activation following in situ vaccination with CpG oligodeoxynucleotide in a dual tumor-bearing mouse model. We demonstrate that OX40 imaging was able to predict tumor responses on day 9 after treatment on the basis of tumor tracer uptake on day 2, with greater accuracy than both anatomical and blood-based measurements. These studies provide key insights into global T cell activation following local CpG treatment and indicate that 64Cu-DOTA-AbOX40 is a promising candidate for monitoring clinical cancer immunotherapy strategies.

Keywords: Cancer immunotherapy; Immunology; Oncology; T cells.

Publication types

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

MeSH terms

  • Animals
  • Cancer Vaccines / immunology*
  • Cancer Vaccines / pharmacology
  • Cell Line, Tumor
  • Copper Radioisotopes / pharmacology*
  • HEK293 Cells
  • Humans
  • Lymphocyte Activation*
  • Mice, Inbred NOD
  • Mice, SCID
  • Neoplasms, Experimental / diagnostic imaging*
  • Neoplasms, Experimental / immunology*
  • Neoplasms, Experimental / therapy
  • Oligodeoxyribonucleotides / pharmacology
  • Positron-Emission Tomography*
  • Receptors, OX40 / immunology*
  • T-Lymphocytes / immunology*


  • CPG-oligonucleotide
  • Cancer Vaccines
  • Copper Radioisotopes
  • Copper-64
  • Oligodeoxyribonucleotides
  • Receptors, OX40
  • TNFRSF4 protein, human