Macrophages are metabolically heterogeneous within the tumor microenvironment

Xenia Geeraerts, Juan Fernández-Garcia, Felix J. Hartmann, Kyra E. de Goede, Liesbet Martens, Yvon Elkrim, Ayla Debraekeleer, Benoit Stijlemans, Anke Vandekeere, Gianmarco Rinaldi, Riet De Rycke, Mélanie Planque, Dorien Broekaert, Elisa Meinster, Emile Clappaert, Pauline Bardet, Aleksandar Murgaski, Conny Gysemans, Frank Aboubakar Nana, Yvan SaeysSean C. Bendall, Damya Laoui, Jan Van den Bossche, Sarah Maria Fendt, Jo A. Van Ginderachter*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Macrophages are often prominently present in the tumor microenvironment, where distinct macrophage populations can differentially affect tumor progression. Although metabolism influences macrophage function, studies on the metabolic characteristics of ex vivo tumor-associated macrophage (TAM) subsets are rather limited. Using transcriptomic and metabolic analyses, we now reveal that pro-inflammatory major histocompatibility complex (MHC)-IIhi TAMs display a hampered tricarboxylic acid (TCA) cycle, while reparative MHC-IIlo TAMs show higher oxidative and glycolytic metabolism. Although both TAM subsets rapidly exchange lactate in high-lactate conditions, only MHC-IIlo TAMs use lactate as an additional carbon source. Accordingly, lactate supports the oxidative metabolism in MHC-IIlo TAMs, while it decreases the metabolic activity of MHC-IIhi TAMs. Lactate subtly affects the transcriptome of MHC-IIlo TAMs, increases L-arginine metabolism, and enhances the T cell suppressive capacity of these TAMs. Overall, our data uncover the metabolic intricacies of distinct TAM subsets and identify lactate as a carbon source and metabolic and functional regulator of TAMs.

Original languageEnglish
Article number110171
JournalCell Reports
Issue number13
Publication statusPublished - 28 Dec 2021

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