Epstein-Barr Virus Life Cycle: Lytic and Latent Phases Explained

EBV has a complex life cycle with two distinct phases:

1. Lytic Cycle (Productive Infection)

1. Attachment and Entry: EBV binds to receptors on B lymphocytes or epithelial cells.
2. Penetration: Fusion with cell membrane releases viral genome into cytoplasm.
3. Replication: Viral DNA replicates in nucleus using host machinery; viral proteins synthesized.
4. Assembly: New virions assemble in nucleus, acquire envelope from nuclear membrane.
5. Release: Mature virions bud from cell surface, often destroying the host cell.

2. Latent Cycle (Non-Productive Infection)

1. Latency Establishment: After initial lytic infection, some B cells maintain viral genome as a non-replicating episome in the nucleus.
2. Reactivation: Immunosuppression or other triggers can reactivate the virus, restarting the lytic cycle.
3. Viral Persistence: Latency allows lifelong persistence. Associated with lymphoproliferative disorders and malignancies.

The lytic and latent cycles enable EBV to establish long-term infections and ensure survival/transmission in humans.