Scanning transmission electron tomography to study virus assembly: Review for the retirement of Paul Walther.

In this short and popular review, we summarise some of our findings analysing the replication cycles of large DNA viruses using scanning transmission electron tomography (STEM tomography) that we applied in the laboratory of Paul Walther. It is also a tribute to a very kind and expert scientist, who recently retired. Transmission electron microscopy (TEM), in particular cryo-EM, has benefited tremendously from recent developments in instrumentation.

Analysis of PERV-C superinfection resistance using HA-tagged viruses.

Background: Using pigs as organ donors has advanced xenotransplantation to the point that it is almost ready for clinical use. However, there is still a zoonotic risk associated with xenotransplantation, and the potential transmission of porcine endogenous retroviruses needs to be surveyed. Despite significant attempts to eliminate this risk, by the selection of PERV-C free pigs with low expression of PERV-A, -B, and by the genome-wide inactivation of PERV using CRISPR/Cas9, the impact of superinfection resistance (SIR) was not investigated.

Presence of Intact Hepatitis B Virions in Exosomes.

Background & Aims: Hepatitis B virus (HBV) was identified as an enveloped DNA virus with a diameter of 42 nm. Multivesicular bodies play a central role in HBV egress and exosome biogenesis. In light of this, it was studied whether intact virions wrapped in exosomes are released by HBV-producing cells.

Vaccinia virus H7-protein is required for the organization of the viral scaffold protein into hexamers.

Viruses of the giant virus family are characterized by a structurally conserved scaffold-capsid protein that shapes the icosahedral virion. The vaccinia virus (VACV) scaffold protein D13, however, transiently shapes the newly assembled viral membrane in to a sphere and is absent from the mature brick-shaped virion. In infected cells D13, a 62 kDa polypeptide, forms trimers that arrange in hexamers and a honey-comb like lattice.