Reciprocal regulation of mesenchymal stem cells and immune responses

Mesenchymal stem/stromal cells (MSCs) exist in almost all tissues and participate in tissue regeneration and homeostasis. In-vitro-expanded MSCs are employed as therapeutics for autoimmune diseases, organ failures, and many other chronic disorders. Remarkably, the reparative and homeostatic maintenance functions of MSCs rely on their interaction with the inflammatory microenvironment. Here, we discuss the characteristics and functions of MSCs under different pathophysiological conditions and highlight how the immunomodulatory functions of MSCs are altered in accordance with the inflammatory cues. We hope to provide new insights into the diverse immunoregulatory properties of MSCs during tissue regeneration and therapy.