Positron Emission Tomography Probes for Imaging Cytotoxic Immune Cells

Abstract

Non-invasive positron emission tomography (PET) imaging of immune cells is a powerful approach for monitoring the dynamics of immune cells in response to immunotherapy. Despite the clinical success of many immunotherapeutic agents, their clinical efficacy is limited to a subgroup of patients. Conventional imaging, as well as analysis of tissue biopsies and blood samples do not reflect the complex interaction between tumour and immune cells. Consequently, PET probes are being developed to capture the dynamics of such interactions, which may improve patient stratification and treatment evaluation. The clinical efficacy of cancer immunotherapy relies on both the infiltration and function of cytotoxic immune cells at the tumour site. Thus, various immune biomarkers have been investigated as potential targets for PET imaging of immune response. Herein, we provide an overview of the most recent developments in PET imaging of immune response, including the radiosynthesis approaches employed in their development.

Smart probes for optical imaging of T cells and screening of anti-cancer immunotherapies

“…Capturing the dynamic information rising from the interactions between cancer cells and T cells requires the selection of suitable biomarkers, 130 with radiolabeled PET probes being in a more advanced translational state, as recently reviewed by Whitney and Aarntzen. 131 The molecular targets for T cells are relatively diverse, from generic surface receptors (e.g., CD4, CD8) to T cell activation markers (e.g., PD-1, LAG-3, OX40, IL-2) or more recently, metabolic markers (e.g., 18 F-labeled amino acids and nucleobases).…”