Immunomodulatory properties of bone marrow mesenchymal stem cells.

Bone marrow mesenchymal stem cells (BM-MSCs) are multipotent progenitor cells of mesodermal origin possessing multilineage differentiation potential and ease of expansion in vitro . Over the years, these cells have gained attention owing to their potential in cell-based therapies in treating various diseases. In particular, the wide spectrum of immunoregulatory/immunomodulatory role of MSCs in various clinical conditions has gained immense attention. The immunomodulatory properties of BM-MSCs are mediated by either cell-cell contact (interactions with various immune cells in a context-dependent manner), paracrine mode of action or extracellular vesicles, making them a potential option as immunosuppressants/immunomodulators in treating various clinical conditions. A plethora of studies have demonstrated that MSCs do so by exhibiting a profound effect on various immune cells for example they can inhibit the proliferation of T cells, B cells, and natural killer cells; modulate the activities of dendritic cells and induce regulatory T cells both in vitro and in vivo . In this review we aim at briefly elucidating the characteristics of BM-MSCs, specifically addressing the current understanding on the hypoimmunogeneticity and immunomodulatory properties of the same with specific reference to their interactions with B cells, T cells, Dendritic cells and natural killer cells. We also aim at reviewing the secretory profile and their role in some clinical conditions that have shown promising outcomes.