Memory CD8+ T cell responses to cancer

Abstract

Long-lived memory CD8⁺ T cells play important roles in tumor immunity. Studies over the past two decades have identified four subsets of memory CD8⁺ T cells - central, effector, stem-like, and tissue resident memory - that either circulate through blood, lymphoid and peripheral organs, or reside in tissues where cancers develop. In this article, we will review studies from both pre-clinical mouse models and human patients to summarize the phenotype, distribution and unique features of each memory subset, and highlight specific roles of each subset in anti-tumor immunity. Moreover, we will discuss how stem-cell like and resident memory CD8⁺ T cell subsets relate to exhausted tumor-infiltrating lymphocytes (TIL) populations. These studies reveal how memory CD8⁺ T cell subsets together orchestrate durable immunity to cancer.

Keywords: Central memory (T(CM)); Effector memory (T(EM)); Exhaustion; Resident memory (T(RM)); Stem cell memory (T(SCM)); Tumor immunity.