FIG. 1.

MSC paracrine function regulates immune cell function. MSCs secrete cytokines and growth factors that modulate immune cell response to tissue damage by altering lymphocyte and leukocyte behavior. T cells experience a reduction in responsiveness, increase in IL-4, and increase in regulatory T cell phenotype. Both T cells and NK cells exhibit a decrease in IFN-γ secretion. MSCs impact overall function of B cells, including proliferation and differentiation, and drive macrophages toward the anti-inflammatory M2 phenotype. MSC, mesenchymal stromal/stem cell.