Serological cross-reactions between four polyomaviruses of birds using virus-like particles expressed in yeast

Abstract

Polyomaviruses are aetiological agents of fatal acute diseases in various bird species. Genomic analysis revealed that avian polyomavirus (APyV), crow polyomavirus (CPyV), finch polyomavirus (FPyV) and goose hemorrhagic polyomavirus (GHPyV) are closely related to each other, but nevertheless form separate viral species; however, their serological relationship was previously unknown. As only APyV can be grown efficiently in tissue culture, virus-like particles (VLPs) were generated by expression of the genomic regions encoding the major structural protein VP1 of these viruses in yeast; these were used to elicit type-specific antibodies in rabbits and as antigens in serological reactions. For increased VLP assembly, a nuclear-localization signal was introduced into APyV-VP1. VLPs derived from the VP1 of the monkey polyomavirus simian virus 40 served as control. APyV-, GHPyV-and CPyV-VLPs showed haemagglutinating activity with chicken and human erythrocytes. CPyV-and GHPyV-specific sera showed slight cross-reactions in immunoblotting, haemagglutination-inhibition assay and indirect ELISA. The FPyV-specific serum inhibited the haemagglutination activity of APyV-VLPs slightly and showed a weak crossneutralizing activity against APyV in cell-culture tests. Generally, these data indicate that the four polyomaviruses of birds are serologically distinct. However, in accordance with genetic data, a relationship between CPyV and GHPyV as well as between APyV and FPyV is evident, and grouping into two different serogroups may be suggested. The haemagglutinating activity of APyV, CPyV and GHPyV may indicate similar receptor-binding mechanisms for these viruses. Our data could be useful for the development of vaccines against the polyomavirus-induced diseases in birds and for interpretation of diagnostic test results.

Structural Basis and Evolution of Glycan Receptor Specificities within the Polyomavirus Family

“…Conversely, the absence of hemagglutination activity for a given virus does not preclude glycan receptor binding, as shown for SV40 and its specific sialylated receptor, the GM1 ganglioside (13,15). In the case of avian viruses BFDPyV, CaPyV, and GhPyV, hemagglutination activity has been reported with chicken and human erythrocytes, functionally supporting the sialylated glycan receptor binding properties we report for GhPyV (66,67). However, FiPyV did not hemagglutinate chicken or human erythrocytes (66), suggesting an alternative receptor specificity compared to that of the related viruses, likely influenced by residues surrounding the conserved BC2 loop Neu5Acbinding site.…”

Generation of infectious recombinant Adeno-associated virus in Saccharomyces cerevisiae

“…In many cases host factors identified in the model systems have been validated in the native host [28] confirming the utility of yeast as a model system platform. Yeast has been used also for production of virus-like particles (VLPs) of a number of viruses [29], illustrating the capability of yeast to fold proteins correctly and support multimerization and capsid assembly [30–32]. The utility of yeast as model system for AAV has been explored before [33,34].…”