The immediate early gene of human cytomegalovirus stimulates vascular smooth muscle cell proliferation in vitro and in vivo

Cytomegalovirus (CMV) infection has been carefully studied regarding the relationship with the vascular smooth muscle cell (VSMC) proliferation in either atherosclerosis or post-angioplasty restenosis, but its role in the vessel wall has yet to be elucidated. To clarify the pathogenic ability of CMV in the vessel wall, we transduced the immediate early (IE) gene of CMV into the VSMCs and endothelial cells (ECs) by hemagglutinating virus of Japan-liposome method. The in vitro IE gene transfer demonstrated that the conditioned medium of IE gene transferred ECs enhanced [³H]-thymidine uptake of VSMCs. The enhanced proliferation of the IE gene transferred VSMCs was observed after the stimulation by basic fibroblast growth factor. The in vivo IE gene transfer showed neointimal thickening while the control arteries did not. These findings thus suggest that the expression of CMV-IE gene in the vessel wall may play a role in the fibrocellular neointimal formation or progression of atherosclerosis in vivo.