Thrombospondin-2 prevents cardiac injury and dysfunction in viral myocarditis through the activation of regulatory T-cells

AIMS: Thrombospondin-2 (TSP-2) modulates matrix integrity and myocyte survival in the hypertensive or ageing heart. Whether TSP-2 may affect cardiac inflammation and injury, in particular during acute viral myocarditis, is completely unknown. METHODS AND RESULTS: Therefore, mortality, cardiac inflammation, and function were assessed in TSP-2-null (KO) and wild-type (WT) mice in human Coxsackie virus B3 (CVB3)-induced myocarditis. TSP-2 KO had an increased mortality when compared with WT mice during viral myocarditis. The absence of TSP-2 resulted in increased cardiac inflammation and injury at 14 days, which resulted in depressed systolic function [fractional shortening (FS); 34 ± 2.6 in WT vs. 24 ± 1.8 in KO mice, P