Molecular Imaging of PD-1 Unveils Unknown Characteristics of PD-1 Itself by Visualizing "PD-1 Microclusters"

Adv Exp Med Biol. 2024:1444:197-205. doi: 10.1007/978-981-99-9781-7_13.

Abstract

Programmed cell death-1 (PD-1) is one of the most famous coinhibitory receptors that are expressed on effector T cells to regulate their function. The PD-1 ligands, PD-L1 and PD-L2, are expressed by various cells throughout the body at steady state and their expression was further regulated within different pathological conditions such as tumor-bearing and chronic inflammatory diseases. In recent years, immune checkpoint inhibitor (ICI) therapies with anti-PD-1 or anti-PD-L1 has become a standard treatment for various malignancies and has shown remarkable antitumor effects. Since the discovery of PD-1 in 1992, a huge number of studies have been conducted to elucidate the function of PD-1. Herein, this paper provides an overview of PD-1 biological findings and sheds some light on the current technology for molecular imaging of PD-1.

Keywords: ICI; Immune checkpoint; Immune checkpoint inhibitor; Immunological synapse; Microcluster; Molecular imaging; PD-1; Programmed cell death 1; T cell signaling; Tumor immunotherapy.

MeSH terms

  • B7-H1 Antigen / metabolism
  • Humans
  • Immunotherapy / methods
  • Molecular Imaging
  • Neoplasms* / metabolism
  • Programmed Cell Death 1 Receptor* / metabolism
  • T-Lymphocytes / metabolism

Substances

  • Programmed Cell Death 1 Receptor
  • B7-H1 Antigen