Targeting the adenosine 2A receptor enhances chimeric antigen receptor T cell efficacy
Paul A. Beavis ... Michael H. Kershaw, Phillip K. Darcy
Paul A. Beavis ... Michael H. Kershaw, Phillip K. Darcy
Published March 1, 2017
Citation Information: J Clin Invest. 2017;127(3):929-941. doi:10.1172/JCI89455.
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Categories: Research Article Immunology Oncology

Targeting the adenosine 2A receptor enhances chimeric antigen receptor T cell efficacy

Abstract

Chimeric antigen receptor (CAR) T cells have been highly successful in treating hematological malignancies, including acute and chronic lymphoblastic leukemia. However, treatment of solid tumors using CAR T cells has been largely unsuccessful to date, partly because of tumor-induced immunosuppressive mechanisms, including adenosine production. Previous studies have shown that adenosine generated by tumor cells potently inhibits endogenous antitumor T cell responses through activation of adenosine 2A receptors (A2ARs). Herein, we have observed that CAR activation resulted in increased A2AR expression and suppression of both murine and human CAR T cells. This was reversible using either A2AR antagonists or genetic targeting of A2AR using shRNA. In 2 syngeneic HER2+ self-antigen tumor models, we found that either genetic or pharmacological targeting of the A2AR profoundly increased CAR T cell efficacy, particularly when combined with PD-1 blockade. Mechanistically, this was associated with increased cytokine production of CD8+ CAR T cells and increased activation of both CD8+ and CD4+ CAR T cells. Given the known clinical relevance of the CD73/adenosine pathway in several solid tumor types, and the initiation of phase I trials for A2AR antagonists in oncology, this approach has high translational potential to enhance CAR T cell efficacy in several cancer types.

Authors

Paul A. Beavis, Melissa A. Henderson, Lauren Giuffrida, Jane K. Mills, Kevin Sek, Ryan S. Cross, Alexander J. Davenport, Liza B. John, Sherly Mardiana, Clare Y. Slaney, Ricky W. Johnstone, Joseph A. Trapani, John Stagg, Sherene Loi, Lev Kats, David Gyorki, Michael H. Kershaw, Phillip K. Darcy

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Stimulation of the CAR results in upregulation of the A2AR, which limits...

Figure 1

Stimulation of the CAR results in upregulation of the A2AR, which limits CAR T cell cytokine production.

(A) 2 × 106 murine anti-HER2 CAR T cells were stimulated overnight with either anti-CD3 (0.5 μg/ml)/anti-CD28 (0.5 μg/ml), anti-CMYC tag (1:1,000), or an isotype control. (B) 1 × 106 CAR T cells were cocultured with 1 × 106 24JK or 24JK-HER2 tumor cells for 4 hours. (A and B) Stimulated cells were lysed and RNA isolated. Expression of A2aR and housekeeping gene L32 was determined by qPCR. (A) Data were normalized to unstimulated CAR T cells and are presented as the mean ± SEM of 4 individual experiments. (B) Data are presented as the mean ± SD from a representative experiment of n = 3. (C–F) 2 × 105 CAR T cells were cocultured with 1 × 105 24JK/24JK-HER2 (C and E) or E0771/E0771-HER2 (D and F) tumor cells in the presence or absence of NECA (1 μM) and SCH58261 (1 μM). Supernatants were collected after 16 hours and the cytokine concentration determined. Data are represented as mean ± SD of triplicates from a representative experiment of n = 4. “θ” indicates that the recorded value was above the maximum indicated on the graph. “LXSN T cells” refers to T cells transduced with the empty retroviral vector (LXSN) control. *P < 0.05, **P < 0.01, ***P < 0.001 by 1-way ANOVA; NS, not significant.