Paper

Macrophages target PVR/CD155 on colorectal cancer cells via REVERBalpha

Farooq, Mohammad S, Herrmann, Katharina, Malz, Lennart, Helm, Laura, Schichta, Natalia, Gutting, Tobias, Ebert, Matthias P, Han, Yu, Betge, Johannes, Kato, Dominik, Sticht, Carsten, Burgermeister, Elke, Hauber, Veronika, Gaiser, Timo, Herweck, Frank, Cerwenka, Adelheid

2026

Overview

Background & Aims: Patients with microsatellite-instable (MSI) colorectal cancer (CRC) benefit from immune checkpoint therapy. For patients with microsatellite-stable (MSS) non-MSI tumors targeting alternative immune checkpoints, such as the Poliovirus receptor (PVR/CD155), may extend response to checkpoint inhibitors and thereby improve outcomes. The drugable transcription factor REVERBalpha (NR1D1) is a master repressor of macrophage function. We hypothesized that regulation of PVR allows elimination of tumor cells by macrophage-directed precision therapy. Methods: Human CRC cell lines (MSS+: HT29, SW480; MSI+: HCT116), patient-derived organoids (MSS+ PDOs) and tissues were assessed by PCR, Western blot, immunohistochemistry and flow cytometry. 3D co-cultures of CRC cells with macrophages derived from THP1 monocytic leukemia cells or peripheral blood of healthy donors were analysed by microscopy and viability assays. Functional perturbation of PVR and REVERBalpha was achieved by CRISPR/Cas9-sgRNA gene modification, synthetic ligands or blocking antibodies (Abs). Results: REVERBalpha bound a cognate DNA-element in the -1 kb human PVR gene promoter, and its agonist (SR9009) super-repressed, whereas its antagonist (SR8278) de-repressed transcription of PVR mRNA in macrophages. Macrophages with CRISPR-modified REVERBalpha were unresponsive to ligand, devoid of PVR protein, showed more phagocytosis, tumor cell efferocytosis and expression of genes related to host immunity (PDL1, TLR4 e.a.) than clones with the wild-type receptor. Macrophages lowered the viability of tumor cells, potentiated by PVR blocking Ab or PVR knock-out in tumor cells. Consistently, REVERBalpha antagonist augmented tumor cell death in co-cultures with macrophages and PVR blocking Ab. Conclusion: Co-addressing the checkpoint axis REVERBalpha-PVR may represent a novel intervention strategy for patients with MSS+ CRC.Competing Interest StatementThe authors have declared no competing interest.Funder Information DeclaredDeutsche Forschungsgemeinschaft, https://ror.org/018mejw64, GRK2727, FOR5806Hector-Stiftung, https://ror.org/0427ycx88Merck (Germany), https://ror.org/04b2dty93University Medical Centre Mannheim, https://ror.org/05sxbyd35, TMR

• Publisher: Cold Spring Harbor Laboratory Press
• Subject: Blocking antibodies / CD155 antigen / Cell death / Colorectal cancer / CRISPR / Flow cytometry / Immune checkpoint inhibitors / Immunohistochemistry / Macrophages / Microsatellite instability / Monocytes / Monocytic leukemia / Organoids / Peripheral blood / Phagocytosis / TLR4 protein / Toll-like receptors / Tumor cells / Tumors