Overview
- The study, published Friday in the Journal of Experimental Medicine, used intravital two-photon microscopy in mice to record macrophages actively attacking and engulfing live melanoma cells.
- Researchers identified a distinct CD169-positive macrophage subset that, when specifically depleted, allowed melanoma tumours to grow larger in the mouse model.
- The macrophage engulfment appeared to occur independently of T cells and B cells, meaning these cells may act as an innate first line of defence against tumours.
- Analyses of human skin and melanoma biopsies from Melanoma Institute Australia found the same CD169-positive macrophages enriched at tumour margins, supporting clinical relevance.
- Teams now plan to map how CD169+ macrophages communicate with T cells and to test ways to boost or mobilise them as a complementary, still investigational, strategy to improve immunotherapy outcomes.