Structural analysis of herpes simplex virus by optical super-resolution imaging

Laine, Romain F.; Albecka, Anna; van de Linde, Sebastian; Rees, Eric J.; Crump, Colin M.; Kaminski, Clemens F.

Although it is now clear that the tegument is not as disordered as previously thought, its structure and organization are still poorly understood. Structural information is also missing on the distribution of specific glycoproteins in the virus envelope. EM studies of biological materials are often restricted to highly ordered structures and, therefore, cannot be used to resolve viral tegument and envelope organization. Moreover, although EM and ET are powerful tools to visualize overall physical structure, their ability to localize specific proteins is limited. Optical techniques do not suffer this latter disadvantage; however, they are limited by optical diffraction, with a typical lateral resolution of B200 nm. This resolution is comparable to the entire virus diameter and thus too coarse to reveal structural information. Recently, a host of sub-wavelength resolution optical imaging methods have been developed to circumvent the diffraction limit [16] [17] [18] . These super-resolution methods include stimulated-emission depletion microscopy 19 and single-molecule localization microscopy (SMLM), such as photoactivated localization microscopy (PALM) 20 , stochastic optical reconstruction microscopy 21 (STORM) and direct STORM (dSTORM) 22 . Although PALM 20, 23 , stimulated-emission depletion 24 or dSTORM [25] [26] [27] have begun to be used in the investigation of viral replication and structure, their application in the context of virology research is still in its infancy.