The Cellular and Molecular Origin of Tumor-Associated Macrophages
Menée à l'aide d'un modèle murin, cette étude montre que la croissance d'une tumeur mammaire induit l'accumulation de macrophages associés aux tumeurs qui, d'un point de vue phénotypique et fonctionnel, diffèrent des macrophages présents dans les tissus mammaires
Long recognized as an evolutionarily ancient cell type involved in tissue homeostasis and immune defense against pathogens, macrophages are being rediscovered as regulators of several diseases including cancer. Here, we show that in mice, mammary tumor growth induces the accumulation of tumor-associated macrophages (TAMs) that are phenotypically and functionally distinct from mammary tissue macrophages (MTMs). TAMs express the adhesion molecule Vcam1 and proliferate upon their differentiation from inflammatory monocytes, but do not exhibit an “alternatively activated” phenotype. TAM differentiation depends on the transcriptional regulator of Notch signaling, RBPJ; and TAM, but not MTM, depletion restores tumor-infiltrating cytotoxic T cell responses and suppresses tumor growth. These findings reveal the ontogeny of TAMs and a discrete tumor-elicited inflammatory response, which may provide new opportunities for cancer immunotherapy.
Science , résumé, 2014