IPLS Seminar - Prof Ari Helenius (ETH Zurich)

Early steps in virus infection

Abstract: Despite their simplicity as life-less particles, viruses have during their evolution acquired amazing insights into the biology of their host cells and organisms, which they exploit during different stages in their replication cycle. By tracking a variety of animal viruses during cell attachment, endocytic entry, biosynthesis, assembly, and exit, it has been possible for my coworkers and me to open backdoors into cellular phenomena that would otherwise be hard to discover. In my lecture, I will first focus on the multivalent interaction between the virus particle and cell surface receptors using the Simian virus 40 as an example. For most viruses, the steps after binding involve the activation of endocytic processes ranging from clathrin coat-mediated endocytosis to macropinocytosis and lipid-raft dependent mechanisms. After penetration of intracellular membranes, the cytosolic viruses (or their capsids) must be uncoated to allow replication and transcription of the genome. Not only do the uncoating strategies differ between viruses, but they have proven to be complex and highly dependent on assistance provided by cellular factors.