Immune modulation via paracrine signaling by mesenchymal stem cells

"Immune modulation via paracrine signaling by mesenchymal stem cells" refers to the collective set of mechanisms through which **mesenchymal stem/stromal cells** (MSCs) influence the immune system primarily through the secretion of soluble factors—rather than direct cell-to-cell contact. These secreted products include cytokines, chemokines, growth factors such as PGE2 and IDO[1][2], anti-inflammatory proteins like TSG‑6[2], and extracellular vesicles containing microRNAs[4]. Through these mediators: > - **MSCs can induce polarization** of macrophages from pro-inflammatory M1 phenotype toward anti-inflammatory M2 phenotype. > - They promote expansion/differentiation toward regulatory T cells and B regulatory cells. > - They suppress activation/proliferation/cytotoxicity in effector lymphocytes including NK cells. > - They reduce mast cell degranulation and neutrophil inflammatory mediator release. This broad-spectrum immunomodulatory effect underlies much interest in using either live MSCs or their secretome/exosomes as therapeutic agents for diseases characterized by excessive inflammation or autoimmunity. However, "immune modulation via paracrine signaling by MSCs" is not itself a discrete molecular target but rather describes an entire class of cellular actions involving multiple molecules/pathways[1][3][4]. **Note:** This entry does *not* correspond to a specific receptor/protein/enzyme/transporter but instead describes an aggregate biological process mediated by many molecules released from mesenchymal stem/stromal cells. It should therefore be classified as "incorrect" if strict molecular targeting information is required.

Other names

MSC immunomodulationMSC paracrine immune regulationMesenchymal stem cell secretome-mediated immune modulationParacrine effects of MSCs on immunity

Not applicable as this is not a discrete molecular target but rather a cellular mechanism. However, the mechanism involves secretion by MSCs of soluble factors such as prostaglandin E2 (PGE2), indoleamine 2,3-dioxygenase (IDO), interleukin 10 (IL‑10), tumor necrosis factor-stimulated gene 6 protein (TSG‑6), microRNAs in extracellular vesicles/exosomes, etc., which collectively modulate immune cell phenotypes and functions[1][2][3][4].