Tumor-Infiltrating Lymphocytes: What, Why, And How

Introduction

Nature is incredibly smart, creative, and efficient in so many ways, and the human immune system is a testament to that. As we’ve begun to slowly understand and unlock the complexities of immune mechanisms through technology, we’ve found better ways to fight disease. Immunotherapy of cancer is a prime example – it’s based on natural immune defenses that can be optimized to target specific cancers. Here, we focus on an important player in such targeted, highly personalized cancer therapies called tumor-infiltrating lymphocytes (TILs).

Two modes of immunotherapy for cancer have garnered much attention in the past decade: immune checkpoint inhibitors and adoptive cell transfer (ACT). TILs belong to the latter, along with chimeric antigen receptor (CAR) T cells, and are used to treat late-stage patients, including those patients who don’t respond to checkpoint inhibitor drugs. CAR T cell therapy is perhaps the better-known ACT modality, but TILs have proved more promising in treating certain solid tumors. This article will look at the tapped and untapped potential of TILs in cancer care, as well as the limitations of their use and some challenges in therapy development.