3D Scaffold-Based Macrophage Fibroblast Coculture Model Reveals IL-10 Dependence of Wound Resolution Phase

Persistent inflammation and impaired repair in dermal wound healing are frequently associated with cell-cell and cell-matrix miscommunication. A direct coculture model of primary human myofibroblasts (MyoFB) and M-CSF-differentiated macrophages (M-M) in fibrillar three-dimensional Collagen I (Coll I) matrices is developed to study intercellular interactions. The coculture experiments reveal the number of M-M regulated MyoFB dedifferentiation in a dose-dependent manner. The amount of MyoFB decreases in dependence of the number of cocultured M-M, even in the presence of MyoFB-inducing transforming growth factor beta(1) (TGF-beta(1)). Gene expression analysis of matrix proteins (collagen I, collagen III, ED-A-fibronectin) confirms the results of an altered MyoFB phenotype. Additionally, M-M is shown to be the main source of secreted cytokine interleukin-10 (IL-10), which is suggested to affect MyoFB dedifferentiation. These findings indicate a paracrine impact of IL-10 secretion by M-M on the MyoFB differentiation status counteracting the TGF-beta(1)-driven MyoFB activation. Hence, the in vitro coculture model simulates physiological situations during wound resolution and underlines the importance of paracrine IL-10 signals by M-M. In sum, the 3D Coll I-based matrices with a MyoFB-M-M coculture form a highly relevant biomimetic model of late stages of wound healing.