The impact of inflationary cytomegalovirus-specific memory T cells on anti-tumour immune responses in patients with cancer

Abstract

<p id="d117023e332">Human cytomegalovirus ( <span style="fixed-case">CMV</span>) is a ubiquitous, persistent beta herpesvirus. <span style="fixed-case">CMV</span> infection contributes to the accumulation of functional antigen‐specific <span style="fixed-case">CD</span>8 ⁺ T‐cell pools with an effector‐memory phenotype and enrichment of these immune cells in peripheral organs. We review here this ‘memory T‐cell inflation’ phenomenon and associated factors including age and sex. ‘Collateral damage’ due to <span style="fixed-case">CMV</span>‐directed immune reactivity may occur in later stages of life – arising from <span style="fixed-case">CMV</span>‐specific immune responses that were beneficial in earlier life. <span style="fixed-case">CMV</span> may be considered an age‐dependent immunomodulator and a double‐edged sword in editing anti‐tumour immune responses. Emerging evidence suggests that <span style="fixed-case">CMV</span> is highly prevalent in patients with a variety of cancers, particularly glioblastoma. A better understanding of <span style="fixed-case">CMV</span>‐associated immune responses and its implications for immune senescence, especially in patients with cancer, may aid in the design of more clinically relevant and tailored, personalized treatment regimens. ‘Memory T‐cell inflation’ could be applied in vaccine development strategies to enrich for immune reactivity where long‐term immunological memory is needed, e.g. in long‐term immune memory formation directed against transformed cells. </p>