Dutch researcher sheds new light on coronaviruses

Using novel techniques, Dutch researcher Matthijs Raaben has cast new light on the replication of coronaviruses, a family of viruses including the cause of SARS. He has shown, using luminescent viruses, how coronaviruses use host cells and how we can use the intracellular processes to attack the virus.

Coronaviruses are entirely dependent, for their replication and dissemination, on the cells they infect. Using microchips, Raaben has successfully investigated various processes involving the mouse hepatitis coronavirus (MHV) in a cell. His discoveries included a finding that the proliferation of MHV can be restrained by blocking the proteasome of a cell, the mechanism that deals with cleaning out surplus proteins. Restricting this clean-up action may also combat infections from the coronavirus in living animals.

Attacking the virus at the level of the host cells may be a better way of avoiding an increase in resistance to antiviral medicines. This is because the treatment does not attack the virus directly, but rather the processes in the cell that the virus needs in order to replicate itself.

Luminescent viruses
Raaben used microchips for his research, but also a new technique - bioluminescence imaging - to track the virus in a living organism. He arranged for the virus to start producing a luminescent protein, derived from a firefly. This light could then be detected using an extremely light-sensitive camera, allowing the spread of the virus to be monitored closely. The major benefit of this is that only one mouse is needed for research into different phases of a virus infection, instead of a different mouse for each phase.

Coronaviruses are known to be the cause of respiratory tract and intestinal infections in various types of animals such as chickens, cats and pigs. In 2003, however, it transpired that a coronavirus was also the cause of SARS, an illness that has since claimed the lives of more than 800 human victims. We need to know more about this group of viruses in order to be in a better position to combat any new outbreaks of SARS or other coronaviruses.

Raaben's research into the interactions taking place between coronaviruses and the host is part of the project headed by Vidi prizewinner Xander de Haan.