Activation of human monocytes/macrophages by hypo-osmotic shock

Abstract

Phagocytosis and secretion of interleukins and growth factors put the macrophage in the centre of the wound healing process. For the last four years over 400 human ulcers have been treated in elderly and paraplegic patients by local application of monocytes prepared from a blood unit, in a unique, closed, sterile system. The process of preparation includes a step of hypo-osmotic shock, which induces monocyte/macrophage activation. This is different from any other known method of activation. In the present study we evaluated the efficacy of the hypo-osmotic shock. We found enhanced levels of IL-1 (P = 0.004) and IL-6 (P = 0.001) in the incubation medium (100% autologous serum) of the activated cells, as compared with controls, prepared in the same system. The IL-1 reached a plateau after 6 and 12 h incubation at 37°C, in both experimental and control incubation medium. The level of IL-6 was further elevated after 12 and 24 h incubation in experimental and control incubation mediums (P = 0.001). The phagocytosis of fluorescent beads was markedly enhanced after hypo-osmotic shock (P = 0.005). The osmotic shock induced macrophages were compared to those stimulated with LPS, and osmotic shock was proved to be at least as efficient method of stimulation as LPS.