All CVB serotypes and clinical isolates induce irreversible cytopathic effects in primary cardiomyocytes

Abstract

Coxsackievirus B3 (CVB3) has been identified as a major causative agent of acute and chronic myocarditis, but the involvement of other CVB serotypes in myocarditis has not been investigated. To dissect the pathological properties of different CVB serotypes toward primary cardiomyocytes, we tested their effects on primary cardiomyocyte cultures from neonatal rats. Morphological abnormalities were examined by both light and fluorescence microscopy after Hoechst 33342 staining, and loss of cell viability was estimated by MTT assay. All six CVB serotypes showed a similar degree of severe toxicity toward primary cardiomyocytes. CVB clinical isolates had cytopathic effects (CPEs) similar to those of their respective CVB reference strains. Within 1-2 days of infection with multiplicities of infection MOI 50, the cells began to experience morphological changes including cell shrinkage, rounding-up, and slight nuclear condensation. The irreversible loss of cell viability was readily observed within 3-5 days following virus infection. These results suggest that all six CVB serotypes induce direct, irreversible toxicity towards cardiomyocytes, which eventually leads to the death of infected cells. These findings indicate that the variations in CVB serotype are not the limiting factor determining the susceptibility of cardiomyocytes to CVB infection.

Viral Persistence and Chronic Immunopathology in the Adult Central Nervous System following Coxsackievirus Infection during the Neonatal Period

“…Two recent publications suggest that the presence of CVB in the heart relies upon the generation of noncytolytic variants with 5Ј terminal mutations and deletions (35,38). Yet it is not clear from this study if attenuated, noncytolytic variants are found in human patients and how these variants may out-compete wildtype virus, assuming that CVB grows without major impediments in cardiomyocytes, as has been shown in vitro (2,30,39). Furthermore, recent data suggest that engineered deletions of the 5Ј UTR of an infectious CVB3 clone (similar, although not identical, to those identified by Kim et al) failed to give rise to infectious progeny or detectable levels of viral protein expression (33).…”

Characterization of Infections of Human Leukocytes by Non-Polio Enteroviruses

“…We previously found that EVs, including CVA24 and CVB3, efficiently replicate in a wide variety of cells, resulting in an induction of cytotoxicity and a loss of viable cells [30][31][32] . Indeed, EV replication has been found to shut down the normal function of host cells and is directly linked to disease.…”

Primary neurons become less susceptible to coxsackievirus B5 following maturation: The correlation with the decreased level of CAR expression on cell surface

“…Immunocytochemistry was performed essentially as described previously [Ahn et al, 2005a]. Cells were fixed with 4% paraformaldehyde, permeabilized with 0.05% TritonX-100 in 0.1 M phosphate buffer (pH 7.4).…”