Garvan Researchers Capture CD169 Macrophages Killing Melanoma, Halting Tumor Growth in 1 Mouse Model
Updated
Updated · Inside Precision Medicine · May 27
Garvan Researchers Capture CD169 Macrophages Killing Melanoma, Halting Tumor Growth in 1 Mouse Model
5 articles · Updated · Inside Precision Medicine · May 27
CD169-positive macrophages in mouse skin were filmed at the melanoma margin engulfing live cancer cells in real time, giving direct evidence that they help contain tumor expansion.
CSF1R blockade that depleted those macrophages led to faster tumor growth, showing the anti-tumor effect came from this tissue-resident subset rather than from T cells or B cells.
Two-photon intravital imaging placed the cells near blood vessels in the hypodermis and tumor periphery, helping explain why macrophages can either promote or suppress tumors depending on subtype and location.
Around half of advanced melanoma patients respond to checkpoint inhibitors, and the findings point to macrophage-targeted therapies or combinations that could help immune-cold tumors resist less T-cell-focused treatment.
Macrophages can both help and harm tumors. Can science safely weaponize this 'double agent' to fight cancer?
If our bodies have a hidden 'immune army,' why does it so often lose the war against cancer?
2026 Breakthrough: CD169-Positive Macrophages Filmed Attacking Melanoma—Implications for Next-Generation Immunotherapy
Overview
In May 2026, researchers at the Garvan Institute of Medical Research achieved a major breakthrough by capturing the first real-time video of CD169-positive macrophages actively engulfing live melanoma cells in mice. This discovery provides direct evidence of how the innate immune system can fight cancer within living tissue. Previously, the role of macrophages in tumors was unclear, as they could both help and hinder cancer growth. By identifying CD169-positive macrophages as key defenders, especially in the hypodermis, scientists now have a clearer understanding of their protective function. Advanced imaging made this possible, opening new paths for cancer treatment research.