Figure 5.

HCV virion heterogeneity. (a) Transmission EM pictures of HCV virions, reproduced from Catanese et al. [14], with permission. HCV particles were purified over heparin column and the high infectivity fractions isolated by density gradient ultracentrifugation. Note the diversity in virion size and the absence of apparent symmetry. The close-up pictures represent examples of particles with possible internal structures; although the 2D imaging technique used cannot exclude the superposition of separate particles. (b) Theoretical models for the HCV lipoviroparticle. Lipoprotein constituents might be incorporated within the HCV particle, thus forming a true lipoviroparticle (left panel), as supported by André et al. [101,110] or peripherally associated, as already proposed by Lindenbach et al. [5]. Please see the main text for the detailed description.