Inhibition of wound healing in mice by local interferon alpha/beta injection

Tumour vascular endothelium has been observed previously to be damaged by local injection of interferon alpha/beta, apparently before the onset of necrosis and regression of experimental tumours. In order to distinguish the effect of interferon alpha/beta on the vasculature from direct effects on tumour, the angiogenesis of wound healing was chosen for study. Injection of interferon alpha/beta subcutaneously adjacent to each wound at days 0 to 4 resulted in a markedly reduced rate of healing with poor edge reunion by day 3. Histologically, there was delay in the initiation of proliferation of not only capillary buds, but also fibroblasts and, to a lesser extent, epithelium across the incision. Nevertheless, no endothelial injury was seen at light or electron microscopic level. Healing subsequently resumed the normal pattern, though delayed, day 9 wounds resembling normal day 5 wounds. We conclude that interferon alpha/beta inhibits wound healing in mice by inhibition of proliferation of many cell types in addition to endothelium.