Generation of recombinant European bat lyssavirus type 1 and inter-genotypic compatibility of lyssavirus genotype 1 and 5 antigenome promoters.

Bat lyssaviruses (Fam. Rhabdoviridae) represent a source for the infection of terrestial mammals and the development of rabies disease. Molecular differences in the replication of bat and non-bat lyssaviruses and their contribution to pathogenicity, however, are unknown. One reason for this is the lack of reverse genetics systems for bat-restricted lyssaviruses. To investigate bat lyssavirus replication and host adaptation, we developed a reverse genetics system for European bat lyssavirus type 1 (EBLV-1; genotype 5). This was achieved by co-transfection of HEK-293T cells with a full-length EBLV-1 genome cDNA and expression plasmids for EBLV-1 proteins, resulting in recombinant EBLV-1 (rEBLV-1). Replication of rEBLV-1 was comparable to that of parental virus, showing that rEBLV-1 is a valid tool to investigate EBLV-1 replication functions. In a first approach, we tested whether the terminal promoter sequences of EBLV-1 are genotype-specific. Although genotype 1 (rabies virus) minigenomes were successfully amplified by EBLV-1 helper virus, in the context of the complete virus, only the antigenome promoter (AGP) sequence of EBLV-1 was replaceable, as indicated by comparable replication of rEBLV-1 and the chimeric virus. These analyses demonstrate that the terminal AGPs of genotype 1 and genotype 5 lyssaviruses are compatible with those of the heterologous genotype.