Life Science Paradigm Challenge

Cancer-fighting immune cells can still kill tumors even if they aren't actually 'eating' them—they have other ways to win.

March 20, 2026

Original Paper

CAR-MACROPHAGES ACTIVATE ANTI TUMOR T CELLS IN THE ABSENCE OF PHAGOCYTOSIS

bioRxiv · 10.64898/2026.03.11.710792

The Takeaway

Chimeric Antigen Receptor (CAR) macrophages were assumed to work primarily by engulfing (eating) tumor cells. This paper reveals that just the physical contact between the CAR and the tumor is enough to trigger a chemical signal that activates the rest of the immune system, overturning the assumption that phagocytosis is the essential step.

From the abstract

Macrophages are highly abundant within the tumor microenvironment and serve as an essential bridge between innate and adaptive immune responses. Thus, they have emerged as promising candidates for chimeric antigen receptor (CAR)-based therapeutic strategies. Previous studies demonstrated that adenovirally-transduced CAR-macrophages (CAR-M), used in clinical trials, can perform tumor cell phagocytosis, reshape the tumor microenvironment towards a proinflammatory state, and promote host T cell act