Immune involvement in wound healing.

Both in vitro and in vivo studies have demonstrated that the presence of both macrophages and T lymphocytes at the wound site is essential in order for the normal healing process to occur. Both macrophages and T lymphocytes possess the capacity to regulate essential steps in the process of wound healing. The presence of macrophages is essential for the initiation and maintenance of wound fibroblast activity. T cells do not appear to be required for the initiation of the healing process, and healing can progress in the absence of T lymphocytes, but the presence of an intact T-cell immune system is essential for a normal outcome, indicating that the T cells probably exert a regulatory influence over macrophage-induced activities. Further research is still required into the interaction of these immune cells, their secretory products, and other wound elements before our understanding of the mechanism of wound healing is complete.