The microenvironment in cancerous tissues is immunosuppressive and pro-tumorigenic, whereas the microenvironment of tissues affected by chronic inflammatory disease is pro-inflammatory and anti-resolution. Despite these opposing immunological states, the metabolic states in the tissue microenvironments of cancer and inflammatory diseases are similar: both are hypoxic, show elevated levels of lactate and other metabolic by-products and have low levels of nutrients. In this Review, we describe how the bioavailability of lactate differs in the microenvironments of tumours and inflammatory diseases compared with normal tissues, thus contributing to the establishment of specific immunological states in disease. A clear understanding of the metabolic signature of tumours and inflammatory diseases will enable therapeutic intervention aimed at resetting the bioavailability of metabolites and correcting the dysregulated immunological state, triggering beneficial cytotoxic, inflammatory responses in tumours and immunosuppressive responses in chronic inflammation.

癌组织中的微环境是免疫抑制和促肿瘤发生的，而受慢性炎症性疾病影响的组织的微环境是促炎症和抗消退的。尽管存在这些相反的免疫状态，但癌症和炎症性疾病的组织微环境中的代谢状态是相似的：两者都是缺氧的，乳酸和其他代谢副产物的水平升高，并且营养物质的水平较低。在这篇综述中，我们描述了与正常组织相比，乳酸的生物利用度在肿瘤和炎症性疾病的微环境中有何不同，从而有助于疾病中特定免疫状态的建立。清楚地了解肿瘤和炎症性疾病的代谢特征将有助于进行治疗干预，旨在重置代谢物的生物利用度并纠正失调的免疫状态，从而引发肿瘤中有益的细胞毒性、炎症反应和慢性炎症中的免疫抑制反应。