Using single-cell multiomics and genetic models, Song and Kharel et al. showed that, paradoxically, both sustained A2AR expression under chronic antigen exposure and hypoxia, and complete loss of A2AR drive the transition of TCFhi memory-like progenitor (Tpro) cells to exhausted T cells. A2AR expression was rapidly induced upon TCR stimulation and was required to sustain CD8+ T cell functions. Persistent A2AR expression promoted continuous TCR engagement and CD8+ T cell exhaustion via activation of the GαS-cAMP-PKA pathway. A2AR depletion led to epigenetic remodeling and activation of CD122 (IL-2Rβ)-dependent signaling, driving exhaustion.
Contributed by Ute Burkhardt
(1) Song L (2) Kharel A (3) Xie P (4) Fan J (5) Baker A (6) Zhang Y (7) Zhang Y (8) Cui W (9) Zhang B
Using single-cell multiomics and genetic models, Song and Kharel et al. showed that, paradoxically, both sustained A2AR expression under chronic antigen exposure and hypoxia, and complete loss of A2AR drive the transition of TCFhi memory-like progenitor (Tpro) cells to exhausted T cells. A2AR expression was rapidly induced upon TCR stimulation and was required to sustain CD8+ T cell functions. Persistent A2AR expression promoted continuous TCR engagement and CD8+ T cell exhaustion via activation of the GαS-cAMP-PKA pathway. A2AR depletion led to epigenetic remodeling and activation of CD122 (IL-2Rβ)-dependent signaling, driving exhaustion.
Contributed by Ute Burkhardt
ABSTRACT: Although A2AR is a key immunoregulatory receptor that suppresses CD8(+) T cell activation in response to elevated extracellular adenosine in inflamed or hypoxic microenvironments, its role in CD8(+) T cell differentiation and cell-fate decisions during chronic viral infection and cancer remains poorly understood. Using A2AR-eGFP reporter mice, we show that A2AR expression is rapidly induced by TCR stimulation and persists under chronic antigen exposure and hypoxia, with sustained expression strongly associated with terminal exhaustion via the canonical G_(s)-cAMP-PKA pathway. Paradoxically, A2AR loss does not alleviate exhaustion but instead accelerates differentiation toward the terminally exhausted state. Single-cell multiomics profiling revealed that A2AR deficiency activates CD122 (IL-2R_)-dependent signaling, driving T cell exhaustion. Genetic deletion of CD122 in A2AR-deficient CD8(+) T cells reduced terminal exhaustion, identifying CD122 signaling as a key mediator of A2AR loss-driven exhaustion. Intriguingly, both sustained A2AR expression and A2AR loss converge to promote T cell exhaustion differentiation through distinct mechanisms. These findings uncover a paradoxical role of A2AR in shaping CD8(+) T cell fate choices during chronic infection and cancer.
Author Info:
(1) Department of Medicine and Hematology and Oncology Division, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine Chicago, IL 60611.
ROR: https://ror.org/02p4far57 (2) Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611. (3) Department of Medicine and Hematology and Oncology Division, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine Chicago, IL 60611. ROR: https://ror.org/02p4far57 (4) Department of Medicine and Hematology and Oncology Division, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine Chicago, IL 60611. ROR: https://ror.org/02p4far57 (5) Department of Medicine and Hematology and Oncology Division, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine Chicago, IL 60611. ROR: https://ror.org/02p4far57 (6) Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611. (7) Biotherapy Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, China. ROR: https://ror.org/056swr059 (8) Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611. (9) Department of Medicine and Hematology and Oncology Division, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine Chicago, IL 60611. ROR: https://ror.org/02p4far57
Citation: Proc Natl Acad Sci U S A 2026 Jul 7 123:e2602385123 Epub06/30/2026
