Epstein barr virus

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A Microbial Biorealm page on the genus Epstein barr virus

Classification

Higher order taxa

Viruses; dsDNA viruses, no RNA stage; Herpesvirales; Herpesviridae; (family)Gammaherpesvirinae; (subfamily)Lymphocryptovirus; (genus) Human herpesvirus 4 (species) (1)

Description and significance

Epstein Barr Virus (human herpesvirus 4 or EBV) is a member of the herpesvirdidae family. EBV is the most common and most successful human virus. EBV occurs worldwide, affecting anyone at anypoint in their lifetime. Once infected the virus stays with the person for the rest of their life. The significance of this virus is that aside from its most common infection which is infectious mononucleosis, EBV has also been associated with many other diseases. (2), (1)

Genome structure

The genome of Epstein Barr Virus consists of a linear, double-stranded DNA molecule that is 184 kilobase pairs in length. The genome encodes for about 100 proteins. These proteins are important in regulating viral genes, replication of the viral DNA, providing a structural component for the virions and monitoring the host immune response to the virus. (3)

Cell structure and metabolism

The structure of EBC is a icosahedral nucleocapsid. The nucleocapsid is composed of 162 capsomers. The nucleocapsid is then surrounded by a protein outer covering which is then surrounded by a viral envelope that contains numerous glycoproteins. (2)

Replication of Epstein Barr Virus can occur in two ways:

- infection of skin cells that results in lysis of host cells and release of virions. (1); (4)

- Primary B-cell that results in latency infection. During this stage the virus is constantly being repilicated. This constant replication is due to EBV DNA forming an episome, which becomes circular and joins together, causing continuous replication. (1); (4)

Ecology

EBV is the most common human virus. This virus only infects humans and has not been seen in animals. (5)

Pathology

EBV only infects humans. The most common condition that EBV is associated with is infectious mononucleosis (IM). The symptoms of IM are fever,fatigue, sore throat, tonsillitis, adenopathy and hetatomegaly. The virus causes disease either by lysis of host cells to release virions or by continuous replication during the latency cycle. (5)

Current Research

- Vaccine production- scientists are researchers are trying to create a vaccine for prevention of Epstein Barr Virus. The problem is with all the diseases that are caused by EBV, would be difficult to cure these diseases. Also most people with EBV don't even know they have it and if there aren't any clincial symptoms reported, researchers cannot create a vaccine. (5)

- Research on EBV has also shown a link between maternal EBV infection and Acute Lymphoblasitc Leukemia in the offspring of mothers who were infected with the EBV virus. Researchers examined EBV infection in mothers who's hildren had ALL. (9)

- EBV has also been linked to upper respiratory tract infections in elite athletes. Researchers followd 14 male elite swimmers over a 30-day period of intense training to see if EBV was associated with their upper respiratory tract infections. (6)

References

1. Cohen, J.I. 2000. Epstein Barr Virus Infection. The New England Journal of Medicine, v. 343, p. 481-492.

2. Ebell, M.H. 2004. Epstein Barr Virus Infectious Mononucleosis. American Family Physician, v. 70, p. 1279-1287.

3. Kieff, E.D., and Rickinson A.B. 2007. Epstein Barr Virus. 2655-2701. In: Fields Virology. Wolters Klume Health/Lippincott Williams & Wilkins, Philadelphia, p. 3091.

4. Kieff, E.D., and Rickinson A.B. 2007. Epstein-Barr Virus and Its Replication. 2603-2655. In: Fields Virology. Wolters Klumer Health/Lippincott Williams & Wilkins, Philadelphia, p. 3091

5. Lin, J.C. 2006. Pathogenesis and Therapy of Epstein-Barr Virus Infection: Novel Therapeutic Approaches. 1-37. In: New Developments in Epstein-Barr Virus Research. Nova Science Publishers, New York, p. 314.

6. Gleeson, M., Pyne D.B., Austin, J.P., Francis J.L., Clancy R.L., McDonald W.A., and Fricker P.A. 2002. Epstein-Barr Virus Reactivation and Upper-Respiratory Illness in Elite Swimmers. Medicine and Science in Sports and Exercise, v. 34, p. 411-417.

7. Pellett P.E., and Roizman B. 2007. The Herpesvirdidae Family: A Brief Introduction. 2479-2501. In: Fields Virology. Wolters Klumer Health/Lippincott Williams & Wilkins, Philadelphia, p. 3091.

8. Pottgiesser T., Wolfarth B., Schumacher Y.O., and Bauer G. 2006. Epstein-Barr Virus Serostatus: No Difference Despite Aberrant Patterns in Athletes and Control Group. Medicine and Science in Sports and Exercise, v. 38, p. 1782-1791.

9. Tedeschi, R., Bioigu A., Ogmundsdottir H.M., Marus A., Dillner J., dePaoll P., Gudnadottir M., Koskela P., Pukkala E., Lehtinen T., and Lehtinen M. 2006. Activation of Maternal Epstein-Barr Virus Infection and Risk of Acute Leukemia in Offspring. American Journal of Epidemiology, v. 165, p. 134-137.