Phosphodiesterase-5 inhibition collaborates with vaccine-based immunotherapy to reprogram myeloid cells in pancreatic ductal adenocarcinoma

作者：Nicole Groß, Zhehao Zhang, Jacob T. Mitchell, Soren Charmsaz, Alexei Hernandez, Erin M. Coyne, Sarah M. Shin, Diana Carolina Vargas Carvajal, Dimitrios N. Sidiropoulos, Yeonju Cho, Guanglan Mo, Xuan Yuan, Courtney Cannon, Jayalaxmi Suresh Babu, Melissa R. Lyman, Todd D. Armstrong, Luciane T. Kagohara, Katherine M. Bever, Dung T. Le, Elizabeth M. Jaffee, Elana J. Fertig, Won Jin Ho · 发表于：JCI Insight · 年份：2024 · DOI：10.1172/jci.insight.179292 · 被引用次数：10 · 研究领域：Adenosine and Purinergic Signaling、Immune cells in cancer、Cancer Immunotherapy and Biomarkers

Pancreatic ductal adenocarcinoma (PDAC) is highly lethal and resistant to immunotherapy. Although immune recognition can be enhanced with immunomodulatory agents including checkpoint inhibitors and vaccines, few patients experience clinical efficacy because the tumor immune microenvironment (TiME) is dominated by immunosuppressive myeloid cells that impose T cell inhibition. Inhibition of phosphodiesterase-5 (PDE5) was reported to downregulate metabolic regulators arginase and inducible NOS in immunosuppressive myeloid cells and enhance immunity against immune-sensitive tumors, including head and neck cancers. We show for the first time to our knowledge that combining a PDE5 inhibitor, tadalafil, with a mesothelin-specific vaccine, anti-programmed cell death protein 1, and anti-cytotoxic T lymphocyte-associated protein 4 yields antitumor efficacy even against immune-resistant PDAC. To determine immunologic advantages conferred by tadalafil, we profiled the TiME using mass cytometry and single-cell RNA-sequencing analysis with Domino to infer intercellular signaling. Our analyses demonstrated that tadalafil reprograms myeloid cells to be less immunosuppressive. Moreover, tadalafil synergized with the vaccine, enhancing T cell activation including mesothelin-specific T cells. Tadalafil treatment was also associated with myeloid/T cell signaling axes important for antitumor responses (e.g., Cxcr3, Il12). Our study shows that PDE5 inhibition combined with vaccine-based immunother...