Succinate-loaded tumor cell-derived microparticles reprogram tumor-associated macrophage metabolism

The tumor microenvironment predominantly polarizes tumor-associated macrophages (TAMs) toward an M2-like phenotype, thereby inhibiting antitumor immune responses. This process is substantially affected by metabolic reprogramming; however, reeducating TAMs to enhance their antitumor capabilities through metabolic remodeling remains a challenge. Here, we show that tumor-derived microparticles loaded with succinate (SMPs) can remodel the metabolic state of TAMs. SMPs promote classical M1-like polarization of macrophages by enhancing glycolysis and attenuating the tricarboxylic acid (TCA) cycle in a protein succinylation-dependent manner. Mechanistically, succinate is delivered into the mitochondria and nucleus by SMPs, leading to succinylation of isocitrate dehydrogenase 2 (IDH2) and histone H3K122 within the lactate dehydrogenase A (Ldha) promoter region. Our findings provide a distinct approach for TAM polarization using cell membrane-derived microparticles loaded with endogenous metabolites, a platform that may be used more broadly for posttranslational modification-based tumor immunotherapy.