Crosstalk with Inflammatory Macrophages Shapes the Regulatory Properties of Multipotent Adult Progenitor Cells

Figure 8

Schematic representation of reciprocal effects between rMAPC and macrophages. Inflammatory macrophages (infl MΦ) secrete vast amounts of proinflammatory cytokines (e.g., TNF-α, IL-1β, and IL-6) that prime rMAPC. rMAPC acquire enhanced immunoregulatory properties secreting immunomodulatory mediators that suppress autoreactive T cell proliferation (green trajectory). Moreover, immunoregulatory properties of rMAPC may suppress the M1 phenotype of MΦ or even induce a shift towards an M2 phenotype via the upregulation of PGE2 for instance. Effects of rMAPC secretome may lead to impaired stimulatory capacity of MΦ towards T cells via the downregulation of expression of surface molecules (e.g., CD86) resulting in suppressed autoreactive T cell proliferation (blue trajectory).