CONVERIS Research database:

VIRUS ENTRY - CELL ENTRY OF INFLUENZA A VIRUS AND HUMAN CYTOMEGALOVIRUS

Time period:	2006-12-01 - 2008-11-30
Instrument:	Marie Curie Actions (MCA)
Call:	FP6-2005-MOBILITY-5

Outbreaks of influenza A in humans, birds and animals constitute a continuous major threat to public health as influenza A viruses are capable of species shifts and enormous genetic variation. More than two decades ago, influenza entry was described to occur by endocytosis via clathrin-coated pits. Some evidence was also found for an alternative, clathrin-independent endocytic pathway, but it has not received attention until recently. I will focus on the novel, alternative process. Another virus becoming clinically more important, human cytomegalovirus (hCMV), can be detected in over 80 % of the worlds population. Although most humans keep a latent infection without any symptoms, the virus can be reactivated in immuno-compromised individuals. Furthermore, severe mental defects as well as deafness can occur in case of congenital infection of newborns which is up to 1% of all newborns in the USA. The endocytic entry mechanism of hCMV is largely unknown. Only recently specific integrin-subunits were identified as receptors. I propose to investigate the entry mechanism of hCMV in more detail. In general, the whole analysis will be carried out in a comparative manner to two already quite well studied model pathogens, namely simian virus 40 (SV40) and semliki forest virus (SFV). Experimentally, I will investigate the behaviour of individual, labelled viruses in and on cells using state of the art life-cell-imaging microscopy. I will set up screening assays for influenza A and hCMV infection applying siRNAs in a loss of function screen. Construction of stable cell lines harbouring a conditional RNAi / shRNA knockdown system targeting the clathrin-dependent uptake mechanism will enable me to separate the pathway from the parallel clathrin-dependent pathway. These results are expected to provide crucial information on endocytosis in general as well as reveal key steps in the entry process offering targets for antiviral therapy based on cellular factors.

Scientific co-ordinator:
Ari Helenius (Eidgenossische Technische Hochschule Zuerich)