The 2019 coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has brought an enormous public health burden to the global society. The duration of the epidemic, the number of infected people, and the widespread of the epidemic are extremely rare in modern society. In the initial stage of infection, people generally show fever, cough, and dyspnea, which can lead to pneumonia, acute respiratory syndrome, kidney failure, and even death in severe cases. The strong infectivity and pathogenicity of SARS-CoV-2 make it more urgent to find an effective treatment. Mesenchymal stem cells (MSCs) are a kind of pluripotent stem cells with the potential for self-renewal and multi-directional differentiation. They are widely used in clinical experiments because of their low immunogenicity and immunomodulatory function. Mesenchymal stem cell–derived exosomes (MSC-Exo) can play a physiological role similar to that of stem cells. Since the COVID-19 pandemic, a series of clinical trials based on MSC therapy have been carried out. The results show that MSCs are safe and can significantly improve patients’ respiratory function and prognosis of COVID-19. Here, the effects of MSCs and MSC-Exo in the treatment of COVID-19 are reviewed, and the clinical challenges that may be faced in the future are clarified.

由严重急性呼吸综合征冠状病毒2（SARS-CoV-2）引起的2019冠状病毒病（COVID-19）给全球社会带来了巨大的公共卫生负担。疫情持续时间之长、感染人数之多、疫情范围之广，在现代社会是极为罕见的。感染初期，人们一般会出现发烧、咳嗽、呼吸困难等症状，严重时可导致肺炎、急性呼吸道综合症、肾衰竭，甚至死亡。 SARS-CoV-2的强传染性和致病性使得寻找有效的治疗方法变得更加紧迫。间充质干细胞（MSCs）是一类具有自我更新和多向分化潜力的多能干细胞。它们因其低免疫原性和免疫调节功能而广泛应用于临床实验。间充质干细胞衍生的外泌体（MSC-Exo）可以发挥与干细胞类似的生理作用。自COVID-19大流行以来，开展了一系列基于MSC疗法的临床试验。结果表明，MSCs是安全的，可以显着改善COVID-19患者的呼吸功能和预后。本文综述了MSCs和MSC-Exo在治疗COVID-19中的作用，并阐明了未来可能面临的临床挑战。