Permissiveness of human embryonal fibroblasts for coxsackieviruses B3. Investigations on virus genetic markers in vitro and localization of virus receptor distribution by immunogold replica technique.

In our previous paper (29) we could show, that the replication of four Coxsackie B3 virus strains in human fibroblast lines from different origin was dependent on both the virus strain and the cell line used. Although generally no cytopathic effect could be observed out of one virus strain more pathogenic virus variants could be selected able to destroy virus-sensitive as well as insensitive fibroblasts. The present study was designed to characterize these virus strains by using several in vitro genetic markers. Differences were found concerning plaque size and the temperature marker, whereas the other markers (d, DD, DEAE-D) remained constant. Furthermore, these models of persistent as well as lytic CVB3 infection were analysed by immunoelectron microscopy to study the interaction of viral ligands with cellular receptors. The qualitative and quantitative differences in adsorption of the CVB3 strains to two human fibroblast lines as well as to HeLa cells corresponded well with the virological results. They underline that even in vitro in human cell lines of different origin changes in distribution, quantity and quality of receptors were demonstrable forming the base for the various virus sensitivity.