A group B coxsackievirus/poliovirus 5' nontranslated region chimera can act as an attenuated vaccine strain in mice.

The linear, single-stranded enterovirus RNA genome is flanked at either end with a nontranslated region (NTR). By replacing the entire 5' NTR of coxsackievirus B3 (CVB3) with that from type 1 poliovirus, a progeny virus was obtained following transfection of HeLa cells. The chimeric virus, CPV/49, replicates like the parental CVB3 strain in HeLa cells but is attenuated for replication and yield in primary human coronary artery endothelial cell cultures, in a human pancreas tumor cell line, and in primary murine heart fibroblast cultures.

Mutations in a conserved enteroviral RNA oligonucleotide sequence affect positive strand viral RNA synthesis.

We showed earlier that a transition mutation U234C, located within the completely conserved 5 nucleotide (nt) tract 5'-CGUUA (nt232-236) in the 5' non-translated region (NTR) of the coxsackievirus B3 (CVB3) genome, attenuated CVB3 cardiovirulence in mice. To further explore the role of the sequence, we induced two single and one double transversion mutations in the conserved 5mer in a cardiovirulent CVB3 genome. The mutated sites partially or totally reverted to parental wild-type when progeny viruses were passaged at 37 degrees C, but remained stable when transfection and subsequent passages were performed at 33.

Progress toward vaccines against viruses that cause heart disease.

Of the numerous viruses that have been implicated as causes of viral inflammatory cardiomyopathy, only the 6 serotypes of the group B coxsackieviruses (CVB 1-6) and adenovirus type 2 (Ad 2) have been regularly linked to heart disease on the basis of both clinical investigations as well as animal models (in the case of the coxsackieviruses). Of these, only the coxsackieviruses offer a truly well-characterized system for not only investigations using a small animal disease model (myocarditis in mice) but for studies of the virus at the molecular level and in cell culture systems. The pending worldwide eradication of the related enteroviruses, the polioviruses, will further emphasize the importance of the coxsackieviruses in years to come.