Figure S2 from Olaparib and Radiotherapy Induce Type I Interferon– and CD8+ T Cell–Dependent Sensitization to Immunotherapy in Pancreatic Cancer

Valvo, Victoria M.; Zhang, Qiang; Jiang, Long; Holcomb, Erin A.; Pearson, Ashley N.; Edmunds, Anna G.; Faulkner, Hailey G.; James, Jadyn G.; Tate, Akshay; Huber, Amanda K.; Wang, Zhuwen; Guo, Yupei; Karnak, David; Parsels, Leslie A.; Parsels, Joshua D.; Lei, Yu L.; Rehemtulla, Alnawaz; Lin, Heng; Carpenter, Eileen S.; Wahl, Daniel R.; Sahai, Vaibhav; Lawrence, Theodore S.; Green, Michael D.; Morgan, Meredith A.

doi:10.1158/1535-7163.29234033

Figure S2 from Olaparib and Radiotherapy Induce Type I Interferon– and CD8⁺ T Cell–Dependent Sensitization to Immunotherapy in Pancreatic Cancer

journal contribution

posted on 2025-06-04, 07:21 authored by Victoria M. Valvo, Qiang Zhang, Long Jiang, Erin A. Holcomb, Ashley N. Pearson, Anna G. Edmunds, Hailey G. Faulkner, Jadyn G. James, Akshay Tate, Amanda K. Huber, Zhuwen Wang, Yupei Guo, David Karnak, Leslie A. Parsels, Joshua D. Parsels, Yu L. Lei, Alnawaz Rehemtulla, Heng Lin, Eileen S. Carpenter, Daniel R. Wahl, Vaibhav Sahai, Theodore S. Lawrence, Michael D. Green, Meredith A. Morgan

Supplemental Figure 2. (A) Tumor growth inhibition analysis for Figure 2A conducted on day 13. Tumor growth inhibition was calculated [1-(average tumor volume of treated group/average tumor volume of control group)] x 100%. Mean tumor volume (MTV) ± standard deviation (SD) are denoted for each treatment group along with the calculated percent tumor growth inhibition (%TGI). (B) C57BL/6 mice with subcutaneous mT4 tumors were treated with αPD-L1 pre-, concurrent, or post-olaparib and radiation treatment. The different schedules are concurrent treatment with αPD-L1 (olaparib on days 1-5, and 8-12; radiation on day 1; αPD-L1 treatment on days 0 and 3), pre-treatment with αPD-L1 (olaparib on days 7-11 and 14-18; radiation on day 7; αPD-L1 treatment on days 0 and 3) and post-treatment with αPD-L1 (olaparib on days 0-4 and 7-11; radiation on day 0; αPD-L1 treatment on days 7 and 10). Data represent mean tumor volumes ± SEM from n= 10 (IgG), 20 (concurrent treatment), 20 (pre-treatment), and 20 (post-treatment) tumors per treatment group. (C) Serum was collected for each treatment condition on day 15 from 3 mice undergoing treatment in panel B. Complete blood cell count was conducted at the University of Michigan by the Unit for Laboratory Animal Medicine (RRID: SCR_025790) using a Heska HT5 Element. Percentage of white blood cells and lymphocytes from total serum are shown. (D) Tumor growth inhibition analysis for Figure 2B conducted on day 13. Tumor growth inhibition was calculated [1-(average tumor volume of treated group/average tumor volume of control group)] x 100%. MTV ± SD are denoted for each treatment group along with the calculated TGI. (E) Mouse weights monitored throughout treatment with olaparib, radiation, and αPD-L1. This data is from mice used Figure 2F. Data represent the average mouse weight (g) ± SEM from n= 6 (IgG), 7 (αPD-L1), 6 (olaparib+IgG), 7 (olaparib+αPD-L1), 8 (RT+IgG), 10 (RT+αPD-L1), 7 (olaparib+RT+IgG) and 9 (olaparib+RT+αPD-L1) mice per treatment group. (F) Individual tumor growth curves from mice used in Figure 2F. Data are represented as tumor volume and show n= 6 (IgG), 7 (αPD-L1), 6 (olaparib+IgG), 7 (olaparib+αPD-L1), 8 (RT+IgG), 10 (RT+αPD-L1), 7 (olaparib+RT+IgG), and 9 (olaparib+RT+αPD-L1) tumors per treatment group. (G, H) Tumor growth inhibition analysis for Figure 2D conducted on day 31 (G) and Figure 2F conducted on day 44 (H). Tumor growth inhibition was calculated [1-(average tumor volume of treated group/average tumor volume of control group)] x 100%. MTV ± SD are denoted for each treatment group along with the calculated TGI.

Funding

National Institutes of Health (NIH)

History

ARTICLE ABSTRACT

PARP inhibitors sensitize pancreatic ductal adenocarcinoma (PDAC) to radiation by inducing DNA damage and replication stress. These mechanisms also have the potential to enhance radiation-induced type I interferon (T1IFN)–mediated antitumoral immune responses. We hypothesized that the PARP inhibitor olaparib would also potentiate radiation-induced T1IFN to promote antitumor immune responses and sensitization of otherwise resistant PDAC to immunotherapy. To test this hypothesis, we assessed the effects of olaparib and radiation on T1IFN production and sensitivity to αPD-L1 immunotherapy, as well as on the tumor microenvironment by single-cell RNA sequencing. We found that olaparib enhanced T1IFN production after radiation and had superior therapeutic efficacy in immunocompetent models. Olaparib and radiation treatment sensitized PDAC tumors to αPD-L1, resulting in decreased tumor burden and a 33% complete response rate. Combination treatment provided durable immune responses as shown by tumor rejection upon tumor rechallenge of previously cured mice. Furthermore, single-cell RNA sequencing analysis revealed that combination treatment induced an immunogenic tumor microenvironment characterized by interferon (IFN) responses in both PDAC and myeloid cell populations, macrophage polarization, and increased CD8+ terminal effector T-cell frequency and activity, findings which were confirmed by IHC and flow cytometry. Furthermore, CD8+ T cells and T1IFN signaling were required for therapeutic efficacy as host depletion of CD8+ T cells or the T1IFN receptor diminished treatment responses. Overall, our results indicate that olaparib enhances radiation-induced T1IFN-mediated immune signaling and subsequently an adaptive immune response, thus sensitizing pancreatic cancer to αPD-L1 therapy, supporting an ongoing clinical trial of this therapy in patients with PDAC.See related commentary by Buchsbaum, p. 840

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Keywords

Dna Damage And Repair Immunotherapy Checkpoint blockade Tumor Microenvironment Immune cells and the microenvironment

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CC BY