GLYCOPROTEIN-MEDIATED BIOLOGICAL PROPERTIES OF A HOST-RANGE MUTANT OFJUNIN VIRUS

The biological properties mediated by the main envelope glycoprotein ( GP1) of a mouse-attenuated mutant of Junin virus, named Cl67, were inv estigated in comparison with its parental strain XJC13. In contrast to the parental strain, this mutant was unable to multiply in primary cu ltures of mouse embryo fibroblasts (MEFs). Impairment of Cl67 multipli cation was associated with a lack of virus binding to MEF, probably du e to an altered interaction between GP1 and cellular receptors. Antige nic and immunogenic characterization of GP1, performed by neutralizati on assays, demonstrated that, under certain conditions, polyclonal and monoclonal antibodies exhibited differential affinity and specificity for each virus. Cl67-infected Vero cells showed a marked pH-dependent fusion capability, suggesting more efficient low pH triggering of fus ion by mutant virus GP1 in comparison with the parental strain.