Rheumatoid arthritis (RA) is considered to be a degenerative and progressive autoimmune disorder. Although several medicinal regimens are used to treat RA, potential adverse events such as metabolic disorders and increased risk of infection, as well as drug resistance in some patients, make it essential to find an effective and safe therapeutic approach. Mesenchymal stromal/stem cells (MSCs) are a group of non-hematopoietic stromal cells with immunomodulatory and inhibitory potential. These cells exert their regulatory properties through direct cell-to-cell interactions and paracrine effects on various immune and non-immune cells. As conventional therapeutic approaches for RA are limited due to their side effects, and some patients became refractory to the treatment, MSCs are considered as a promising alternative treatment for RA. In this review, we introduced various experimental and clinical studies conducted to evaluate the therapeutic effects of MSCs on animal models of arthritis and RA patients. Then, possible modulatory and suppressive effects of MSCs on different innate and adaptive immune cells, including dendritic cells, neutrophils, macrophages, natural killer cells, B lymphocytes, and various subtypes of T cells, were categorized and summarized. Finally, limitations and future considerations for the efficient application of MSCs as a therapeutic approach in RA patients were presented.

类风湿性关节炎（RA）被认为是一种退行性、进行性自身免疫性疾病。尽管有多种药物治疗方案可用于治疗 RA，但潜在的不良事件（例如代谢紊乱和感染风险增加）以及某些患者的耐药性使得寻找有效且安全的治疗方法至关重要。间充质基质/干细胞（MSC）是一组具有免疫调节和抑制潜力的非造血基质细胞。这些细胞通过直接的细胞间相互作用以及对各种免疫和非免疫细胞的旁分泌作用发挥其调节特性。由于 RA 的传统治疗方法因其副作用而受到限制，并且一些患者对治疗变得难治，因此 MSC 被认为是 RA 的一种有前途的替代疗法。在这篇综述中，我们介绍了为评估间充质干细胞对关节炎和类风湿性关节炎动物模型的治疗效果而进行的各种实验和临床研究。然后，对MSCs对不同先天性和适应性免疫细胞（包括树突状细胞、中性粒细胞、巨噬细胞、自然杀伤细胞、B淋巴细胞和各种亚型T细胞）可能的调节和抑制作用进行了分类和总结。最后，提出了 MSC 作为 RA 患者治疗方法的有效应用的局限性和未来考虑因素。