Consensus nomenclature for CD8 + T cell phenotypes in cancer

Oncoimmunology. 2015 Feb 25;4(4):e998538. doi: 10.1080/2162402X.2014.998538. eCollection 2015 Apr.

Abstract

Whereas preclinical investigations and clinical studies have established that CD8+ T cells can profoundly affect cancer progression, the underlying mechanisms are still elusive. Challenging the prevalent view that the beneficial effect of CD8+ T cells in cancer is solely attributable to their cytotoxic activity, several reports have indicated that the ability of CD8+ T cells to promote tumor regression is dependent on their cytokine secretion profile and their ability to self-renew. Evidence has also shown that the tumor microenvironment can disarm CD8+ T cell immunity, leading to the emergence of dysfunctional CD8+ T cells. The existence of different types of CD8+ T cells in cancer calls for a more precise definition of the CD8+ T cell immune phenotypes in cancer and the abandonment of the generic terms "pro-tumor" and "antitumor." Based on recent studies investigating the functions of CD8+ T cells in cancer, we here propose some guidelines to precisely define the functional states of CD8+ T cells in cancer.

Keywords: CD8+ T cells; IFNγ; anergy; anticancer immunity; cytotoxicity; effector; exhaustion; senescence; stemness.