Expected and Unexpected Features of the Newly Discovered Bat Influenza A-like Viruses

Ma, Wenjun; García-Sastre, Adolfo; Schwemmle, Martin

Several lines of evidence indicate that bat influenza A-like viruses are of low risk for the human population. This is based on the observation that viral particles of HL17NL10 or HL18NL11 generated by reverse genetics failed to productively infect human cells, which correlates with the general inability of the bat HAs and NAs to mediate cell entry into these cells [3, 4, 7] . An important feature of an IAV is the possibility to exchange genomic RNA segments with other IAVs, resulting in novel genotypes and phenotypes with zoonotic potential. However, coinfection experiments demonstrated no reassortment between bat chimeric viruses and conventional IAVs [8, 9] . The larger sequence diversity between bat influenza A-like virus and conventional IAV genomes most likely caused this packaging incompatibility between these viruses. In addition, specific incompatibilities at the protein level might further prevent the emergence of reassortant viruses after coinfection occurrence. This especially includes the bat influenza A-like polymerase subunits PB1 and PA, since these two proteins do not support the polymerase activity of conventional IAVs [8, 9] .