Myeloid Cells in Cutaneous Wound Repair

Cutaneous wound repair is a complex, dynamic process with the goal of rapidly sealing any breach in the skin's protective barrier. Myeloid cells compose a significant proportion of the inflammatory cells recruited to a wound site and play important roles in decontaminating the injured tissue of any invading microorganisms. Subsequently, myeloid cells are able to influence many aspects of the healing response, in part through their capacity to release a large array of signaling molecules that allow them to communicate with and regulate the behavior of other wound cells and in turn, be themselves exquisitely regulated by the wound microenvironment. Macrophages, for example, appear to play important, temporally changing roles in the initiation of scarring and subsequently in matrix remodeling to resolve fibrosis. In this way, myeloid cells seem to play both positive (e.g., pathogen killing and matrix remodeling) and negative (e.g., scarring) roles in wound repair. Further research is of course needed to elucidate the precise temporal and spatial myeloid cell phenotypes and behaviors and ultimately to design effective strategies to optimize the beneficial functions of these cells while minimizing their detrimental contributions to improve wound healing in the clinic.