Epstein-Barr Virus

The Epstein-Barr virus (EBV), or human herpesvirus 4, is part of the herpes family and causes cancer. It is one of the most common viruses in humans and is correlated to the pathogenesis of multiple autoimmune diseases including rheumatoid arthritis, systemic lupus, dermatomyositis, and multiple sclerosis.

It can also cause several lymphoproliferative disorders and cancers. Most people gain adaptive immunity after being infected by EBV. In the US half of all five-year-olds and 90-95% of adults have evidence of infection. Even when children get infected there are usually no visible symptoms. When infected as a teenager 35-69% of the time it causes mononucleosis.

Yvonne Barr and M. Anthony Epstein discovered the virus and became its namesake. Epstein attended a lecture on a unrecognized syndrome which was a “endemic variant” of the disease that later took his name. In 1963 a specimen was obtained to be cultured. In 1964 the results of the culture were published.

The viruses various programs of gene expression can be broadly categorized as being lytic cycle or latent cycle.

Unlike other viruses the Epstein-Barr virus can be maintained and manipulated in the laboratory in continual latency allowing for continued studying of this part of the viral life cycle. It is theorized that EBV executes some or all of its repertoire of gene expression in order to establish a persistent infection.

These programs subvert infected B-lymphocytes to proliferate and bring infected cells to the sites at which the virus presumably persists. Once the host establishes immunity the virus turns off most of its genes only reactivating occasionally to produce fresh virions. EBV can persist in bone marrow.

It can infect a number of various cell types, including B cells, smooth muscle cells, and epithelial cells. During its normal viral cycle it infects both B cells and epithelial cells.

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