Characterization of the Poliovirus 147S Particle: New Insights into Poliovirus Uncoating

Abstract

A Sabin 1 strain poliovirus (PV) mutant, S1(2Y-1I), carrying a Tyr at amino acid position VP2(142) and an Ile at position VP1(160), can establish persistent infections in HEp-2c cells. This mutant forms atypical 147S particles upon interaction at 0 degrees C with either cells expressing PV receptor (PVR) CD155, or PVR-IgG2a, a chimeric molecule consisting of an extracellular moiety of PVR and the hinge and Fc portion of a mouse IgG2a. Upon interaction with PVR at 37 degrees C, S1(2Y-1I), similar to the parental strain, forms both 135S A particles and 80S empty capsids. At 0 degrees C, surprisingly, at a concentration equal to or greater than 5 nM, PVR-IgG2a induced both the extrusion of VP4 from the capsid of S1(2Y-1I) and the formation of 80S particles. The same transitions were observed at 0 degrees C with the parental strain Sabin 1 at 40 nM PVR-IgG2a. Thus, the formation of 80S particles and VP4 extrusion, considered as one of the steps of PV uncoating, can be temperature-independent at high PVR concentration. This implies that structural changes of the PV capsid occurred following adsorption at low temperature.

Adenovirus Protein VI Mediates Membrane Disruption following Capsid Disassembly

“…Proteolytic cleavage of Ad preprotein VI by the 23K protease results in the generation of an N-terminal amphipathic helix in the mature form of the protein. Upon subsequent infection by these newly formed viral particles, an environmental stimulus triggers a conformational change in the capsid, resulting in release of capsid components and membrane penetration (e.g., poliovirus, reovirus) (7,17,29,(44)(45)(46)51). Ad possesses similarities with these schemes in that the reduced endosomal pH triggers a conformational change in the capsid.…”

Poliovirus mutants excreted by a chronically infected hypogammaglobulinemic patient establish persistent infections in human intestinal cells

“…The kinetics of adsorption of PVpi onto CD155-expressing cells and of elution, and the conformational modification of the capsid induced by CD155 at 37°C are often different from those of the parental lytic PV strains (Duncan and Colbère-Garapin, 1999). We have recently shown that 147S forms are produced upon interaction of particular PV mutants with either CD155-expressing cells or the soluble receptor PVR-IgG2a, at 0°C (Duncan, Pelletier, and Colbère-Garapin, 1998;Pelletier et al, 2003). These 147S forms have the same composition as the virion and may be a conformational intermediate between 160S virions and 135S A particles (Pelletier et al, 2003).…”

Antigenic Evolution of Vaccine-Derived Polioviruses: Changes in Individual Epitopes and Relative Stability of the Overall Immunological Properties

“…Some of the amino acid residues involved in antigenicity changes, for instance, 1090 and 1099 in type 1, 3075 and 3077 in type 2, and 3077 in type 3, do not seem to directly participate in at least the first steps of the virionreceptor interaction, as judged by crystallographic data (6,21,22). Importantly, the type 1 and type 3 Sabin-specific amino acid residues exhibiting a strong tendency to change in vaccinees appear to be quite stable upon passaging in tissue cultures (51,54), though relevant changes may take place under certain conditions (46,47). To reconcile the hypothesis on the optimization of receptor recognition as a cause of changes in the antigenic sites with the stability of these sites in tissue culture, one might consider the possibility that the requirements for optimal virion-receptor interactions in tissue culture and in gut may be different.…”