CD8+ T cells play a crucial role in anti-tumour immunity, but they often undergo exhaustion, which affects the anti-tumour activity of CD8+ T cells. The effect and mechanism of exhausted CD8+ T cells have become the focus of anti-tumour immunity research. Recently, a large number of studies have confirmed that long-term antigen exposure can induce exhaustion. Cytokines previously have identified their effects (such as IL-2 and IL-10) may play a dual role in the exhaustion process of CD8+ T cells, suggesting a new mechanism of inducing exhaustion. This review just focuses our current understanding of the biology of exhausted CD8+ T cells, including differentiation pathways, cellular characteristics and signalling pathways involved in inducing exhaustion, and summarizes how these can be applied to tumour immunotherapy.
Keywords: CD8+ T cells exhaustion; anti-tumour immunity; cytokines; immunoregulatory cells; immunotherapy; inhibitory receptors.
© 2022 John Wiley & Sons Ltd.