mTOR-Mediated Cell Death and Infection

The battle between pathogens and hosts is an ongoing phenomenon that has been studied for centuries. Although multicellular organisms have developed sophisticated immune systems to defend against pathogens, pathogens are often able to successfully infect their hosts. To enhance their chance of survival, pathogens can hijack the host's metabolism, which serves as a critical control point that can potentially impact infections. Mammalian target of rapamycin (mTOR) is the nutrient sensor and central regulator of metabolism in innate and adaptive immune cells. Rapamycin, a drug targeting the mTOR pathway, has been widely used in clinical practice for decades and is relatively safe. However, some unexpected infections occur after long-term administration of rapamycin, indicating the presence of a close relationship between mTOR signaling and the infection process. In this manuscript, we briefly review the mTOR pathway and the current clinical use of rapamycin; we also summarize the role of the mTOR pathway in immune cell death, including apoptosis, necroptosis, pyroptosis, and ferroptosis, and its impact on anti-infection immunity. Finally, potential application of mTOR inhibitor in coronavirus disease 2019 clinical therapy is discussed.