Cross-Talk Between Mesenchymal Stem/Stromal Cells and Dendritic Cells

Mesenchymal stem/stromal cells (MSCs), having both multi-potent differentiation potential and prominent immunomodulatory properties, are seen as a very powerful tool for the therapy of diseases characterized by tissue damage and/or unregulated immune responses. Dendritic cells (DCs) are key immunoregulatory cells at the crossroads between immunity and tolerance, able to fine-tune the whole immune response via regulation of adaptive immunity. Therefore, untangling the complex interactions between DCs and MSCs is crucial for understanding various mechanisms involved in the pathogenesis of immune-related diseases and for the discovery of new therapeutic targets for advanced treatment procedures. From this perspective, we reviewed the data that have been obtained to date regarding the complex effects of MSCs on DC development and functions, delineating the abundant mechanisms involved in these interactions. Additionally, we have pointed out to additional mechanisms of MSC/DC cross-talk that have not been directly proven, but that could have a significant role, not only in DC functions and the maintenance of immune homeostasis, but also in migration, differentiation and the functions of MSCs. For now, much more is known about the influence of MSCs on DCs than vice versa, so more studies should be done in order to fully understand this cross-talk.