Fusobacterium nucleatum Promotes Exosomal LncRNA MANCR Secretion from Colorectal Cancer Cells to Induce PD-L1 Expression in Macrophages.

Fusobacterium nucleatum promotes exosomal MANCR secretion from colorectal cancer cells, increasing PD-L1 expression in macrophages and impairing antitumor immunity.

• Why it matters: Understanding how microbes influence tumor immune environments is crucial for developing effective therapies, especially as immune resistance limits current treatments for colorectal cancer.
• What they did: The study analyzed 54 clinical CRC samples and used humanized mouse models to investigate the F. nucleatum-driven signaling pathway, focusing on exosomal lncRNA MANCR and PD-L1 regulation.
• The result: F. nucleatum-induced MANCR stabilizes PD-L1 in macrophages, suppresses CD8+ T-cell activity, and promotes tumor growth, suggesting that targeting this axis could enhance immune-based therapies.