The last few years have witnessed an increasing body of evidence that challenges the traditional view that immunological memory is an exclusive trait of the adaptive immune system. Myeloid cells can show increased responsiveness upon subsequent stimulation with the same or a different stimulus, well after the initial challenge. This de facto innate immune memory has been termed “trained immunity” and is involved in infections, vaccination and inflammatory diseases. Trained immunity is based on two main pillars: the epigenetic and metabolic reprogramming of cells. In this review we discuss the latest insights into the epigenetic mechanisms behind the induction of trained immunity, as well as the role of different cellular metabolites and metabolic networks in the induction, regulation and maintenance of trained immunity.

过去几年，越来越多的证据挑战了传统观点，即免疫记忆是适应性免疫系统的独有特征。髓细胞可以在初始激发后很久以后用相同或不同的刺激进行刺激时表现出增强的反应性。这事实上先天免疫记忆被称为“训练免疫”，与感染、疫苗接种和炎症性疾病有关。训练有素的免疫基于两个主要支柱：细胞的表观遗传和代谢重编程。在这篇综述中，我们讨论了对诱导训练免疫背后的表观遗传机制的最新见解，以及不同细胞代谢物和代谢网络在训练免疫的诱导、调节和维持中的作用。