What is the life cycle for infectious mononucleosis virus?

Life Cycle of Infectious Mononucleosis Virus (Epstein-Barr Virus):

The Epstein-Barr virus (EBV), which causes infectious mononucleosis, has a complex life cycle involving two distinct phases: the lytic cycle and the latent cycle.

1. Lytic Cycle (Productive Infection):

a) Attachment and Entry: EBV virions attach to specific receptors on the surface of susceptible B lymphocytes or epithelial cells.

b) Penetration: The virions enter the host cell through fusion with the cell membrane, releasing the viral genome into the cytoplasm.

c) Replication: The viral DNA enters the nucleus and begins replication using the host cell's machinery. Viral proteins are synthesized, including structural components of new virions.

d) Assembly: New viral particles are assembled within the nucleus and acquire an envelope from the inner nuclear membrane.

e) Release: The mature virions are released from the host cell by budding from the cell surface. This can lead to the destruction of the host cell.

2. Latent Cycle (Non-Productive Infection):

a) Latency Establishment: After the initial lytic infection, some B lymphocytes can establish a latent infection. The viral genome is maintained as a non-replicating episome (circular DNA) within the nucleus of the B cell.

b) Reactivation: Under certain circumstances, such as immunosuppression, the latent virus can be reactivated, leading to the resumption of the lytic cycle and the production of new infectious virions.

c) Viral Persistence: The latent phase allows EBV to persist in the host for a prolonged period, potentially for life. Latent infection is associated with the development of certain lymphoproliferative disorders and malignancies.

The lytic and latent cycles of EBV enable the virus to establish long-term infections and ensure its survival and transmission within the human population.