Sequential involvement of hypoxia and anti-PD-1 treatment in shaping tumor-regional CD39 + CD8 + T cells highlights immunotherapy-resistant features
Jiajuan Wu, Jiawei Zhai, Leilei Lv, Yaoxin Zhang, Yu Shen, Qiuxia Qu, Cheng ChenBackground
Understanding resistance to anti-programmed cell death protein 1 (PD-1) therapy is critical for developing reversal strategies. Although ectonucleotidase CD39 (ENTPD1) (CD39) + cluster of differentiation 8 (CD8) + T cells have been associated with antitumor responses, the naïve regional distribution of these cells and their dysregulated dynamics as determinants of response or resistance to anti-PD-1 monoclonal antibody (mAb) therapy remain poorly characterized.
Methods
We employed targeted biopsy techniques to characterize the spatial infiltration of CD39 + CD8 + T cells within the tumor microenvironment (TME) of non-small cell lung cancer (NSCLC). It was further performed independent NSCLC cohort, flow cytometry, multiplex immunohistochemistry, single-cell RNA sequencing and functional studies to investigate these cells in vitro and in vivo.
Results
Region-specific CD39 + CD8 + T cells located outside hypoxic zones initially served as potential biomarkers to predict response to anti-PD-1 therapy. However, hypoxia gradients within the TME were associated with regional depletion of these cells in NSCLC. Subsequently, anti-PD-1 mAb treatment further reduced intratumoral CD39 + CD8 + T-cell levels, even in the context of improved oxygenation following tumor regression, suggesting a feedback mechanism modulating antitumor immunity. Multiple assays revealed that the absence of CD39 impaired functional restoration of CD8 + T cells on PD-1 blockade. This finding was corroborated by distinct transcriptional profiles, enhanced cytotoxic/effector signatures, and a more oligoclonal and expanded T-cell receptor (TCR) repertoire in CD39 + CD8 + T cells across the CD8 + T-cell differentiation continuum.
Conclusions
These findings identify CD39 + CD8 + T cells as an important regulator of anti-PD-1 therapy, whereas initial hypoxia followed by anti-PD-1 treatment sequentially shapes tumor-regional localization of these cells, ultimately linking to suboptimal immunotherapeutic responses.