Watching viral entry into living cells in real-time

Viruses cross the cell boundary to infect cells . We will use new methods to directly watch viruses crossing the cell boundary in real-time to observe new details of this important process. We will see how antibodies alter or stop this process and this will help us understand how antibodies prevent viral infection. This will allow us in the long-term to design vaccines in a more rationale way for importatnt diseases such as HIV and flu.

All viruses have to cross the cellular plasma membrane in order to initiate their infection cycle and many methods to prevent infection are based on stopping this process. Hence new methods to study the entry of single viruses will provide fundamental new information about the dynamics of this process and how it is altered or prevented in the presence of neutralizing antibodies.

This proposal aims to build a class 2 facility to study virus infection in real-time using a combination of state-of the art biophysical methods; single molecule fluorescence and high resolution live cell topographic imaging. We will study Herpes Simplex virus, an enveloped virus, and would serve as a paradigm for other enveloped viruses such as influenza, HIV and coronaviruses (eg SARS).

The work will improve our basic understanding of the process of viral entry. While a great deal is known about the individual molecules involved and their interactions, less in known about the kinetics of the process and the detailed time-course of the key events. In addition since the viruses vary in structure with different numbers of copies of protein we can see if there is a correlation between structure and infectivity, an issue that has not been addressed to date due to lack of methods based on the study of individual virions. Importantly we will be able to follow the process of entry directly in real-time and simultaneously measure changes in the cell topography. We can then correlate the behavior of individual virion, whose copy number of key proteins we have determined or to whom a certain number of antibodies have bound, and observe how the entry process differs or in the case of neutralizing antibodies is altered or prevented. This fundamental and new information will allow us to build up a detailed picture of the mechanism of antibody- mediated neutralization. Studies will focus on the details of viral entry and how this is altered pr prevented, for individual virions, in the presence of measured numbers of bound neutralising antibodies.