ABSTRACT
Epstein-Barr virus (EBV), also called human herpes virus 4 (HHV-4), is a member of the herpes family and is one of the most common viruses in humans. EBV can exhibit one of three latency programs: Latency I (latency program), Latency II (default program), or Latency III (growth program). Each latency program leads to the production of a limited, distinct set of viral proteins and viral RNAs. Only EBV-encoded nuclear antigen 1 (EBNA1) is essential for the persistence and replication of the viral genome and is consistently expressed in all types of latencies. Latency III pattern expresses both EBERs and all the EBV latent proteins: the six nuclear antigens (EBNA1, EBNA2, EBNA3A, EBNA3B, EBNA3C, and EBNA-LP) and three membrane proteins (LMP1, LMP2A, and LMP2B). Latency II pattern expresses the EBERs, EBNA1 protein, and the latent membrane proteins (LMP1, LMP2A and LMP2B). Latency I is restricted to the expression of either only EBER, or also EBNA1 protein.
