Host Factors in Viral Life Cycles

Viruses are obligate intracellular parasites that rely on the host cell for expansion. With the development of global analyses techniques like transcriptomics, proteomics and siRNA library screening of complete cellular gene sets, a large range of host cell factors have been discovered that either support or restrict virus growth. Here we summarize some of the recent findings and focus our discussion on the hepatitis C virus and the human immunodeficiency virus, two major pathogens that threat global health. The identification of cellular proteins affecting multiple viruses points to the existence of central regulation nodes that might be exploited for both, a quantitative description of host-virus interactions within single infected cells and the development of novel, broad-spectrum antiviral drugs.