Role of estrogen in suppressing autoimmunity in coxsackievirus B3-induced myocarditis

Abstract

Picornaviruses are small, nonenveloped, single-stranded, positive-sense RNA viruses that cause multiple diseases including myocarditis/dilated cardiomyopathy, Type 1 diabetes, encephalitis, myositis, orchitis and hepatitis. Although picornaviruses directly kill cells, tissue injury primarily results from autoimmunity to self antigens. Viruses induce autoimmunity by aborting deletion of self-reactive T cells during T-cell ontogeny, reversing anergy of peripheral autoimmune T cells, eliminating T regulatory cells; stimulating self-reactive T cells through antigenic mimicry or cryptic epitopes, and by acting as an adjuvant for self molecules released during virus infection. Most autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis and Grave’s disease) predominate in females, but diseases associated with picornavirus infections predominate in males. T regulatory cells are activated in infected females owing to the combined effects of estrogen and innate immunity.