EARLY PROCESSES OF ECHOVIRUS 12-INFECTION - ELUTION, PENETRATION, AND UNCOATING UNDER THE INFLUENCE OF RHODANINE

The early events in the interaction of radioactively labeled, highly purified echovirus 12 with green monkey kidney cells (GMK line) are analyzed in the absence and presence of rhodanine, 2-thio-4-oxothiazolidine, a specific inhibitor of echovirus 12 uncoating. In the presence of rhodanine, elution of modified viral particles is impaired; furthermore, after release of the rhodanine block no elution takes place. In the absence of rhodanine, however, i.e., in normal infection, elution of noninfectious A particles is observed. Apparently, after incubation at 36° in the presence of rhodanine a large proportion of the virus has reached a location-possibly the cytoplasm-from where it cannot be sloughed into the medium. We conclude that in the presence of rhodanine penetration of intact virus takes place, and modification to noninfectious particles is not a necessary precondition for penetration. The infection of these penetrated particles, however, appears to be abortive, since upon removal of rhodanine only a small proportion of cell-associated intact virus is uncoated. In vitro modification of echovirus 12 leads to the formation of particles similar to the described in vivo intermediates of uncoating. Rhodanine is demonstrated to stabilize the virion against heat inactivation and thus inhibits creation of heat degradation products. A generalized hypothesis to explain the mode of action of rhodanine during the early processes of echovirus 12 infection is proposed. © 1979.