Development of a new mouse model for coxsackievirus-induced myocarditis by attenuating coxsackievirus B3 virulence in the pancreas

Abstract

Aims The coxsackievirus B3 (CVB3) mouse myocarditis model is the standard model for investigation of virus-induced myocarditis but the pancreas, rather than the heart, is the most susceptible organ in mouse. The aim of this study was to develop a CVB3 mouse myocarditis model in which animals develop myocarditis while attenuating viral infection of the pancreas and the development of severe pancreatitis. Methods and results We developed the recombinant CVB3 variant H3N-375TS by inserting target sites (TS) of miR-375, which is specifically expressed in the pancreas, into the 3ʹUTR of the genome of the pancreo- and cardiotropic CVB3 variant H3. In vitro evaluation showed that H3N-375TS was suppressed in pancreatic miR-375-expressing EndoC-βH1 cells >5 log10, whereas its replication was not suppressed in isolated primary embryonic mouse cardiomyocytes. In vivo, intraperitoneal (i.p.) administration of H3N-375TS to NMRI mice did not result in pancreatic or cardiac infection. In contrast, intravenous (i.v.) administration of H3N-375TS to NMRI and Balb/C mice resulted in myocardial infection and acute and chronic myocarditis, whereas the virus was not detected in the pancreas and the pancreatic tissue was not damaged. Acute myocarditis was characterized by myocardial injury, inflammation with mononuclear cells, induction of proinflammatory cytokines, and detection of replicating H3N-375TS in the heart. Mice with chronic myocarditis showed myocardial fibrosis and persistence of H3N-375TS genomic RNA but no replicating virus in the heart. Moreover, H3N-375TS infected mice showed distinctly less suffering compared with mice that developed pancreatitis and myocarditis after i.p. or i.v application of control virus. Conclusion In this study, we demonstrate that by use of the miR-375-sensitive CVB3 variant H3N-375TS, CVB3 myocarditis can be established without the animals developing severe systemic infection and pancreatitis. As the H3N-375TS myocarditis model depends on pancreas-attenuated H3N-375TS, it can easily be used in different mouse strains and for various applications.

Opioid-Induced Immunomodulation: Consequences for the Experimental Coxsackievirus B3-Induced Myocarditis Model

“…As described above, the experimental CVB3-induced myocarditis model was established 60 years ago via intraperitoneal application of CVB3 [ 3 , 4 ]. Besides direct infection of the heart, an infection of the pancreas also occurs, which causes the severity of the experimental CVB3 model [ 14 , 15 ]. Mediated by the ongoing pancreatitis, the challenged mice display reduced health status, and successful infection is associated with a strong decline in body weight [ 14 ].…”

“…Besides direct infection of the heart, an infection of the pancreas also occurs, which causes the severity of the experimental CVB3 model [ 14 , 15 ]. Mediated by the ongoing pancreatitis, the challenged mice display reduced health status, and successful infection is associated with a strong decline in body weight [ 14 ]. A first attempt to reduce the severity of the CVB3 model was performed by Pinkert et al, who developed a new mouse model by attenuating CVB3 virulence in the pancreas [ 14 ].…”

“…Mediated by the ongoing pancreatitis, the challenged mice display reduced health status, and successful infection is associated with a strong decline in body weight [ 14 ]. A first attempt to reduce the severity of the CVB3 model was performed by Pinkert et al, who developed a new mouse model by attenuating CVB3 virulence in the pancreas [ 14 ]. Despite better health status and body weight, the novel H3N-375TS virus strain cannot be used for future translational research, because mice displayed no cardiac dysfunction.…”

“…In parallel, inflammatory processes trigger the accumulation of collagen and extracellular matrix in the heart, resulting in left ventricle (LV) stiffening and finally in a reduction of cardiac function [ 11 , 12 ]. Besides the well-described direct infection of the heart in the context of experimental CVB3-induced myocarditis, there is cumulative evidence reporting primarily infection of lymphatic organs [ 13 ], including the pancreas [ 14 , 15 ]. Mediated by the ongoing pancreatitis, the virus also migrates from the pancreas into the heart via the activated/infected immune cells [ 15 , 16 ].…”

Innate Viral Sensor MDA5 and Coxsackievirus Interplay in Type 1 Diabetes Development

“…CVB has been shown to infect cardiomyocytes and pancreatic cells, inducing myocarditis and pancreatitis in both mice and humans [48][49][50][51][52]. Yet, differences do exist when CVB infects mouse and human pancreatic cells.…”