Herpesvirus-induced atherosclerosis in chickens

Repeated experiments have established that infection with Marek's disease herpesvirus (MDV) leads to atherosclerosis in specific pathogen free (SPF) normocholesterolemic chickens. Neither normocholesterolemic nor hypercholesterolemic uninfected SPF chickens develop this disease. The MDV-induced arterial disease is remarkably similar to chronic human atherosclerosis. Cholesterol and saturated cholesteryl esters accumulated in cultured arterial smooth muscle cells (SMC) infected with MDV. Similar preliminary observations were made in vivo. These findings suggest that MDV-induced alteration of SMC lipid metabolism is of major importance in the pathogenesis of MDV-induced atherosclerosis. In addition, immunization with turkey herpesvirus, used commercially to prevent MDV-induced tumors in chickens, also protected against MDV-induced atherosclerosis. This animal model has introduced important new dimensions and tools in atherosclerosis research: a defined etiologic agent (MDV) that causes atherosclerosis in a defined animal of known genetic susceptibility to the etiologic agent. With these tools, important mechanisms in the pathogenesis of atherosclerosis may be established in a relatively short period of time. Further, this animal model should be considered important in other models of atherosclerosis research because herpesvirus infections are ubiquitous in these animals. Finally, because humans are widely and persistently infected with up to five herpesviruses, these studies may lead to the understanding and eventual control of human atherosclerosis.