Can molecular imaging measure T-cell activation?

Abstract

Successful immunotherapy usually depends on activation of T cells in the tumor microenvironment. However, ascertaining whether T-cell activation has occurred in vivo is difficult without invasive tissue sampling. Inducible T-cell costimulator (ICOS) is a specific marker of T-cell activation that can be imaged by radiolabeling an anti-ICOS antibody and performing PET scanning. Hopefully, this agent will be the first of many molecular imaging constructs that can determine whether T-cell activation has occurred and could be used in drug development and clinical trials of cancer immunotherapy.