Entry and Intracellular Transport of Influenza Virus
Gary R. Whittaker and Paul Digard
from: Influenza Virology: Current Topics (Edited by: Yoshihiro Kawaoka). Caister Academic Press, U.K. (2006)
All viruses need to recognize and enter target cells in order to cause infection. For the influenza viruses, an initial interaction with cell surface carbohydrate is followed by receptor-mediated endocytosis that traffics the virion into the endosomal pathway. Exposure to low pH in maturing endosomes triggers fusion of viral and cellular membranes leading to cytoplasmic uncoating of the virion. The released viral genomic ribonucleoproteins (RNPs) are imported into the nucleus where they are transcribed and replicated. Progeny RNPs are later exported to the cytoplasm and eventually arrive at the apical plasma membrane, where final virus assembly and budding take place. As with all viruses, infection is cyclical, and several important events occur during virus assembly and release that have profound effects on the entry process. In this review we survey both virus entry and intracellular transport of the viral components, highlighting both recent discoveries and the interdependence of virus assembly and entry. Where appropriate, we also highlight differences between members of the Orthomyxovirus family read more ...