A biochemical approach reveals cell-surface molecules utilised by Picornaviridae: Human Parechovirus 1 and Echovirus 1

Although receptor virus interactions of several Picornaviridae have been studied in the past, it is becoming apparent that these interactions might be more complex than previously thought. In this study, we have chosen to identify the cell-surface molecules involved in the infectious cycle of two common human pathogens and members of the Piconaviridae family, Echovirus 1 (Echo1) and Human Parechovirus 1 (HPEV1) also known as Echovirus 22. In order to identify the specific cell-surface protein molecules involved in Echo1 and HPEV1 infectious cycles, we have deviced a method, by which free virions were used as an affinity surface, allowing either Echo1 or HPEV1 to bind to solubilised proteins from cells susceptible to the virus infection. The virus-cell-surface protein complexes were then analysed by SDS-PAGE and two-dimensional electrophoresis. Echo1 was shown to bind to two integrin-like proteins of 150 and 120 kDa. While HPEV1 attached to two integrin-like proteins of 120 and 100 kDa. The identity of these proteins was identified via Western blotting. Thus, overall we can conclusively report that Echo1 utilises integrin alpha2beta1, whereas HPEV1 utilises integrin alphavbeta3 on the cell surface.