Professor Leo James, PhD (MRC Laboratory of Molecular Biology, Cambridge, UK)

Abstract

For many viruses, the most complex and hazardous infectious step begins after entry into a cell. Viruses must avoid being detected and disabled by host immunity but actively recruit host proteins to act as co-factors. Encapsidation is a near-universal solution to this problem and extensively employed to protect fragile genomic cargo. In his talk, Leo will discuss some of the consequences of encapsidation focusing on the retrovirus HIV. He will describe how the HIV capsid is a far more dynamic and complex structure than the simple genome package first envisaged. This is illustrated by the recent discovery of charged pores in the capsid that recruit IP6 to promote assembly and stability, and which import nucleotides to allow DNA synthesis to be sequestered from host sensors. Cells have developed various strategies to circumvent capsid protection, and this will be exemplified for non-enveloped viruses like adenovirus.