CXCR4 orchestrates the TOX-programmed exhausted phenotype of CD8+ T cells via JAK2/STAT3 pathway

Evidence from clinical trials suggests that CXCR4 antagonists enhance immunotherapy effectiveness in several cancers. However, the specific mechanisms through which CXCR4 contributes to immune cell phenotypes are not fully understood. Here, we employed single-cell transcriptomic analysis and identified CXCR4 as a marker gene in T cells, with CD8+PD-1high exhausted T (Tex) cells exhibiting high CXCR4 expression. By blocking CXCR4, the Tex phenotype was attenuated in vivo. Mechanistically, CXCR4-blocking T cells mitigated the Tex phenotype by regulating the JAK2-STAT3 pathway. Single-cell RNA/TCR/ATAC-seq confirmed that Cxcr4-deficient CD8+ T cells epigenetically mitigated the transition from functional to exhausted phenotypes. Notably, clinical sample analysis revealed that CXCR4+CD8+ T cells showed higher expression in patients with a non-complete pathological response. Collectively, these findings demonstrate the mechanism by which CXCR4 orchestrates CD8+ Tex cells and provide a rationale for combining CXCR4 antagonists with immunotherapy in clinical trials. [Display omitted] •CXCR4 is highly expressed in CD8+PD-1high exhausted T cells within tumors•Blocking CXCR4 enhances immunotherapy by reducing exhausted CD8+ T cell phenotype•CXCR4 regulates TOX-mediated exhausted phenotype by JAK2-STAT3 pathway•CXCR4 inhibition orchestrates functional and exhausted phenotypes of CD8+ T cells Cao et al. illustrate the anti-tumor immunotherapy efficacy of CXCR4 blockades and its role in modulating the functional and exhausted CD8+ T cell phenotypes by regulating the JAK2-STAT3 pathway. This work supports the combined use of CXCR4 inhibitors and immune checkpoint blockades in clinical trials for cancer treatment.