Attachment of coxsackievirus B3 variants to various cell lines: Mapping ofphenotypic differences to capsid protein VP1

The coxsackievirus as (CVB3) strain Nancy P establishes a persistent carrie r-state infection without visible cytopathic effect in primary human fibrob lasts (HuFi H), whereas the derivative variant PD induces a complete lysis of the cell monolayer. To define the molecular basis of this exceptional gr owth property the complete genomes of both viruses were sequenced and compa red to all published sequences of CVB3. As a result, six unique amino acid substitutions in the VPI capsid protein were observed. Via hybrid virus con struction, the lytic phenotype was transferred to a nonlytic cDNA-generated CVB3. Mapping experiments indicate that the presence of amino acid residue s K78, A80, A91, and 192 in VP1 is sufficient to induce "lytic" infections in HuFi H cells. Binding assays demonstrate that CVB3 Nancy P preferentiall y binds to the human coxsackievirus-adenovirus receptor (CAR), while PD exh ibits a very weak interaction with CAR but strong binding to the decay acce lerating factor (DAF). These results suggest that the mutated amino acid re sidues in VPI are involved in receptor recognition/binding. Moreover, the l ytic replication of CVB3 Po and the hybrid virus in various nonpermissive r odent cell lines indicates that cell surface molecules other than CAR and D AF may be involved in attachment of this variant to cell surfaces. (C) 2000 Academic Press.