Herpesviridae

Taxobox | color=violet
name = "Herpesviridae"
virus_group = i
familia = "Herpesviridae"
subdivision_ranks = Genera
subdivision = Subfamily "Alphaherpesvirinae"
"Simplexvirus"
"Varicellovirus"
"Mardivirus"
"Iltovirus"
Subfamily "Betaherpesvirinae"
"Cytomegalovirus"
"Muromegalovirus"
"Roseolovirus"
Subfamily "Gammaherpesvirinae"
"Lymphocryptovirus"
"Rhadinovirus"
Unassigned
"Ictalurivirus"The "Herpesviridae" are a large family of DNA viruses that cause diseases in animals, including humans.cite book | author = Ryan KJ; Ray CG (editors) | title = Sherris Medical Microbiology | edition = 4th ed. | publisher = McGraw Hill | year = 2004 | id = ISBN 0838585299 ] cite book |chapterurl=http://www.horizonpress.com/avir|author=Mettenleiter et al|year=2008|chapter=Molecular Biology of Animal Herpesviruses|title=Animal Viruses: Molecular Biology|publisher=Caister Academic Press|id= [http://www.horizonpress.com/avir ISBN 978-1-904455-22-6] ] cite book | author = Sandri-Goldin RM (editor). | title = Alpha Herpesviruses: Molecular and Cellular Biology | publisher = Caister Academic Press | year = 2006 | url=http://www.horizonpress.com/ahv | id = [http://www.horizonpress.com/ahv ISBN 978-1-904455-09-7 ] ] The family name is derived from the Greek word "herpein" ("to creep"), referring to the , re-occurring infections typical of this group of viruses. "Herpesviridae" can cause latent or lytic infections.

Viral structure

Herpes viruses all share a common structure—all herpes viruses are composed of relatively large double-stranded, linear DNA genomes encoding 100-200 genes encased within an icosahedral protein cage called the capsid which is itself wrapped in a lipid bilayer membrane called the envelope. This particle is known as the virion.

Herpes virus life-cycle

All Herpes viruses are "nuclear-replicating"—the viral DNA is transcribed to RNA within the infected cell's nucleus.

Infection is initiated when a viral particle contacts a cell with specific types of receptor molecules on the cell surface. Following binding of viral envelope glycoproteins to cell membrane receptors, the virion is internalized and dismantled, allowing viral DNA to migrate to the cell nucleus. Within the nucleus, replication of viral DNA and transcription of viral genes occurs.

During symptomatic infection, infected cells transcribe "lytic" viral genes. In some host cells, a small number of viral genes termed "latency associated transcript" (LAT) accumulate instead. In this fashion the virus can persist in the cell (and thus the host) indefinitely. While primary infection is often accompanied by a self-limited period of clinical illness, long-term latency is symptom-free.

Reactivation of latent viruses has been implicated in a number of diseases (e.g. "Shingles"). Following activation, transcription of viral genes transitions from latency-associated LAT to multiple "lytic" genes; these lead to enhanced replication and virus production. Often, lytic activation leads to cell death. Clinically, lytic activation is often accompanied by emergence of non-specific symptoms such as low grade fever, headache, sore throat, malaise, and rash as well as clinical signs such as swollen or tender lymph nodes and immunological findings such as reduced levels of natural killer cells.

Human herpesviridae infections

There are eight distinct viruses in this family known to cause disease in humans.cite book | author = Whitley RJ | title = Herpesviruses. "in:" Baron's Medical Microbiology "(Baron S "et al", eds.)| edition = 4th ed. | publisher = Univ of Texas Medical Branch | year = 1996 | url = http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mmed.chapter.3567 | id = ISBN 0-9631172-1-1 ]

Zoonotic infections

In addition to the Herpes viruses considered endemic in humans, some viruses associated primarily with animals may infect humans. These are zoonotic infections:

Animal herpesviridae

In animal virology the most important herpesviruses belong to the Alphaherpesvirinae. Research on pseudorabies virus (PrV), the causative agent of Aujeszky's disease in pigs, has pioneered animal disease control with genetically modified vaccines. PrV is now extensively studied as a model for basic processes during lytic herpesvirus infection, and for unravelling molecular mechanisms of herpesvirus neurotropism, whereas bovine herpesvirus 1, the causative agent of bovine infectious rhinotracheitis and pustular vulvovaginitis, is analyzed to elucidate molecular mechanisms of latency. The avian infectious laryngotracheitis virus is phylogenetically distant from these two viruses and serves to underline similarity and diversity within the Alphaherpesvirinae.cite book |chapterurl=http://www.horizonpress.com/avir|author=Mettenleiter et al|year=2008|chapter=Molecular Biology of Animal Herpesviruses|title=Animal Viruses: Molecular Biology|publisher=Caister Academic Press|id= [http://www.horizonpress.com/avir ISBN 978-1-904455-22-6] ] cite book | author = Sandri-Goldin RM (editor). | title = Alpha Herpesviruses: Molecular and Cellular Biology | publisher = Caister Academic Press | year = 2006 | url=http://www.horizonpress.com/ahv | id = [http://www.horizonpress.com/ahv ISBN 978-1-904455-09-7 ] ]
*Subfamily "Alphaherpesvirinae"
**Genus "Simplexvirus"
***"Bovine herpesvirus 2" causes bovine mammillitis and pseudo-lumpyskin disease.
***"Cercopithecine herpesvirus 1", also known as "Herpes B virus", causes a Herpes simplex-like disease in Macaques.
***"Ateline herpesvirus 1", Spider monkey herpesvirus.
**Genus "Varicellovirus"
***"Bovine herpesvirus 1" causes infectious bovine rhinotracheitis, vaginitis, balanoposthitis, and abortion in cattle.
***"Bovine herpesvirus 5" causes encephalitis in cattle.
***"Caprine herpesvirus 1" causes conjunctivitis and respiratory disease in goats.
***"Porcine herpesvirus 1" causes pseudorabies.
***"Equine herpesvirus 1" causes abortion in horses.
***"Equine herpesvirus 3" causes coital exanthema in horses.
***"Equine herpesvirus 4" causes rhinopneumonitis in horses.
***"Canine herpesvirus 1" causes a severe hemorrhagic disease in puppies.
***"Feline herpesvirus 1" causes feline viral rhinotracheitis and keratitis in cats.
***"Duck herpesvirus 1" causes duck plague.
**Genus "Mardivirus"
***"Gallid herpesvirus 2" causes Marek's disease.
***"Gallid herpesvirus 3" (GaHV-3 or MDV-2)
***"Herpesvirus of turkeys" (HVT)
**Genus "Iltovirus"
***"Gallid herpesvirus 1" causes infectious laryngotracheitis in birds.
*Subfamily "Betaherpesvirinae"
**"Porcine herpesvirus 2" causes inclusion body rhinitis in swine.
*Subfamily "Gammaherpesvirinae"
**Genus "Rhadinovirus"
***"Alcelaphine herpesvirus 1" causes bovine malignant catarrhal fever.
***"Alcelaphine herpesvirus 2" causes an antelope and hartebeest version of MCF.
***"Bovine herpesvirus 4"
***"Equine herpesvirus 2" causes equine cytomegalovirus infection.
***"Equine herpesvirus 5" cite book|author=Fenner, Frank J.; Gibbs, E. Paul J.; Murphy, Frederick A.; Rott, Rudolph; Studdert, Michael J.; White, David O.|title=Veterinary Virology (2nd ed.)|publisher=Academic Press, Inc|year=1993|id=ISBN 0-12-253056-X]

Taxonomy

The following genera are included here:

*Subfamily "Alphaherpesvirinae"
**Genus "Simplexvirus"; type species: "Human herpesvirus 1" or Herpes simplex; diseases: cold sores, genital herpes, encephalitis
**Genus "Varicellovirus"; type species: "Human herpesvirus 3" or Varicella-zoster virus; diseases: chickenpox, shingles
**Genus "Mardivirus"; type species: "Gallid herpesvirus 2"
**Genus "Iltovirus"; type species: "Gallid herpesvirus 1"
*Subfamily "Betaherpesvirinae"
**Genus "Cytomegalovirus"; type species: "Human herpesvirus 5"; diseases: mononucleosis
**Genus "Muromegalovirus"; type species: "Murid herpesvirus 1"
**Genus "Roseolovirus"; type species: "Human herpesvirus 6"; diseases: erythema subitum, roseola infantum
*Subfamily "Gammaherpesvirinae"
**Genus "Lymphocryptovirus"; type species: "Human herpesvirus 4" or Epstein-Barr virus; diseases: mononucleosis, Burkitt's lymphoma, nasopharyngeal carcinoma, Hodgkin's disease
**Genus "Rhadinovirus"; type species: "Human Herpesvirus 8", "Saimiriine herpesvirus 2"
*Unassigned
**Genus "Cercopithecine"; type species: "Cercopithecine herpesvirus 1"
**Genus "Ictalurivirus"; type species: "Ictalurid herpesvirus 1"

ee also

References

External links

* [http://www.ihmf.org International Herpes Management Forum]
* http://www.cdc.gov/ncidod/diseases/bvirus.pdf PDF Article on Cercopithecine herpesvirus
* http://www.gsu.edu/bvirus National B Virus Resource Center
* [http://www.horizonpress.com/gateway/animal-viruses.html Animal viruses]