Metabolic reprogramming of the tumor microenvironment to enhance immunotherapy

Immunotherapy represents a promising treatment strategy for targeting various tumor types. However, the overall response rate is low due to the tumor microenvironment (TME). In the TME, numerous distinct factors actively induce immunosuppression, restricting the efficacy of anticancer immune reactions. Recently, metabolic reprogramming of tumors has been recognized for its role in modulating the tumor microenvironment to enhance immune cell responses in the TME. Furthermore, recent elucidations underscore the critical role of metabolic limitations imposed by the tumor microenvironment on the effectiveness of antitumor immune cells, guiding the development of novel immunotherapeutic approaches. Hence, achieving a comprehensive understanding of the metabolic requirements of both cancer and immune cells within the TME is pivotal. This insight not only aids in acknowledging the current limitations of clinical practices but also significantly shapes the trajectory of future research endeavors in the domain of cancer immunotherapy. In addition, therapeutic interventions targeting metabolic limitations have exhibited promising potential as combinatory treatments across diverse cancer types. In this review, we first discuss the metabolic barriers in the TME. Second, we explore how the immune response is regulated by metabolites. Finally, we will review the current strategy for targeting metabolism to not simply inhibit tumor growth but also enhance antitumor immune responses. Thus, we could suggest potent combination therapy for improving immunotherapy with metabolic inhibitors.