Chemoradiotherapy-induced ACKR2+ tumor cells drive CD8+ T cell senescence and tumor recurrence

T cell senescence is a dysfunctional state distinct from exhaustion, yet the mechanism driving CD8+ T cell senescence directly in tumor microenvironment and its impact on cancer prognosis remain elusive. Here, by using single cell RNA sequencing of human cervical cancer tissues, we found that concurrent chemoradiotherapy (CCRT) specifically promoted CD8+ T cell senescence, which is driven by a subpopulation of ACKR2+ CCRT-resistance tumor cells. Mechanistically, in response to CCRT treatment, ACKR2 was directly induced and could also be upregulated through its ligands CC chemokines that produced by activated myeloid and T cells. Subsequently, these ACKR2+ tumor cell subpopulation also produced TGFβ to drive CD8+ T cell senescence, thereby compromising antitumor immunity. Moreover, retrospective analysis showed that ACKR2 level and CD8+ T cell senescence was greatly enhanced in cervical cancer patients who recurred after CCRT, thereby predicting poor prognosis in these patients. Overall, we identified a subpopulation of CCRT-resistant ACKR2+ tumor cells in driving CD8+ T cell senescence and thus tumor recurrence, which may represent a critical mechanism in mediating CCRT resistance, and highlighted the therapeutic potential of targeting ACKR2 or CD8+ T cell senescence in the treatment of CCRT-resistant cancer patients.