Overview
- Researchers published complementary preclinical studies on May 27, 2026 that mapped macrophage niches in lung tumors and filmed CD169‑positive macrophages at melanoma margins actively engulfing live cancer cells.
- A Dartmouth‑led Nature Immunology study found resident macrophages near airways and blood vessels produce chemokines that recruit other immune cells and slow tumor progression, and removing them accelerated tumor growth in models.
- Garvan Institute researchers used intravital two‑photon microscopy to record CD169+ tissue‑resident macrophages at the tumor edge eating melanoma cells, and showed that CSF1R‑based depletion of these cells increased tumor growth.
- Together the results explain why broad, pan‑macrophage therapies have yielded mixed outcomes by showing that macrophage function depends on precise anatomical location rather than single surface markers.
- The studies identified analogous macrophage subsets in human tissue but remain preclinical, so translating this into treatments will require tests that can safely boost beneficial niches while blocking tumor‑supportive macrophages.