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Open access, freely available online Synopses of Research Articles Virus Proteins Prevent Cell Suicide Long Enough to Establish Latent Infection DOI: 10.1371/journal.pbio.0030430 Little more than a small genome encased in protein, a virus can’t reproduce without help from the cell it may ultimately destroy. After attaching to the cell membrane, a virus slips inside the cell, then co-opts its transcription and replication machinery to reproduce. Some viruses, such as the Epstein-Barr virus (EBV), enter a latent stage before they start to reproduce. During latency, the virus expresses its own genes, which help maintain the viral genome until replication begins. In many viral life cycles, including EBV, reproduction continues until the cell bursts and releases a new crop of viruses. As a defense, cells undergo programmed cell death, or apoptosis, which protects other cells by containing the invader. But just as the host depends on apoptosis to survive, viral survival depends on preventing apoptosis. To do this, many DOI: 10.1371/journal.pbio.0030430.g001 viruses use relatives of a protein called Bcl-2 (the viral version is called vBcl- This electron microscopic image of two Epstein Barr Virus virions (viral particles) shows 2). Though many vBcl-2–like proteins, round capsids—protein-encased genetic material—loosely surrounded by the membrane or homologs, can trigger apoptosis, envelope. all the viral Bcl-2 homologs identifi ed so far inhibit apoptosis during viral reproduction. This unexpected temporal regulation functional gene, the virus regained its In a new study, Markus Altmann and of gene expression suggested that