A fatal relationship - Influenza virus interactions with the host cell

Influenza A viruses are important worldwide pathogens for humans and differ ent animal species. The infectious agent is the prototype of the orthomyxov iridae which are characterized by a segmented negative strand RNA genome th at is replicated in the nucleus of the infected cell. The genome has a comb ined coding capacity of about 13 kb and contains the genetic information fo r ten viral proteins. Despite this relatively small coding capacity -large DNA viruses like herpes or poxviruses express about 150-200 gene products-i nfluenza A viruses are able to successfully infect and multiply in a wide r ange of mammalian and avian species. It is therefore not surprising that in fluenza A viruses extensively use and manipulate host cell functions. This includes multiple interactions of viral proteins with cellular proteins. In recent years an increasing amount of information about the identity of the cellular factors that are involved in viral transcription and replication, intracellular trafficking of viral components and assembly of the virus pa rticle has accumulated. This article aims to review recent developments in this field with a focus on cellular factors and processes which are activat ed by the virus to either support viral replication or to counteract host-c ell defense mechanisms.