Betaherpesvirinae
Betaherpesvirinae | |
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Cytomegalovirus infection of a pneumocyte
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Virus classification | |
(unranked): | Virus |
Realm: | Duplodnaviria |
Kingdom: | Heunggongvirae
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Phylum: | Peploviricota |
Class: | Herviviricetes |
Order: | Herpesvirales |
Family: | Orthoherpesviridae
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Subfamily: | Betaherpesvirinae |
Genera | |
See text |
Betaherpesvirinae is a subfamily of
Genera
Betaherpesvirinae consists of the following five genera:[2]
Structure
Viruses in Betaherpesvirinae are enveloped, with icosahedral, spherical to pleomorphic, and Round geometries, and T=16 symmetry. The diameter is around 150-200 nm. Genomes are linear and non-segmented, around 140-240kb in length.[1]
Genus | Structure | Symmetry | Capsid | Genomic arrangement | Genomic segmentation |
---|---|---|---|---|---|
Roseolovirus | Spherical pleomorphic | T=16 | Enveloped | Linear | Monopartite |
Cytomegalovirus | Spherical pleomorphic | T=16 | Enveloped | Linear | Monopartite |
Proboscivirus | Spherical pleomorphic | T=16 | Enveloped | Linear | Monopartite |
Muromegalovirus | Spherical pleomorphic | T=16 | Enveloped | Linear | Monopartite |
Life cycle
Viral replication is nuclear, and is lysogenic. Entry into the host cell is achieved by attachment of the viral glycoproteins to host receptors, which mediates endocytosis. Replication follows the dsDNA bidirectional replication model. DNA templated transcription, with some alternative splicing mechanism is the method of transcription. Translation takes place by leaky scanning. The virus exits the host cell by nuclear egress and budding. Betaherpesviruses typically have highly restricted host ranges, although essentially all mammals, reptiles, and birds are infected with at least one betaherpesvirus species. Transmission routes are transplacental, transplantation, blood transfusion, body fluids, urine, and saliva.[1]
Betaherpesvirinae establish latency (site where virus lies dormant until reactivated) in CD34+
Genus | Host details | Tissue tropism | Entry details | Release details | Replication site | Assembly site | Transmission |
---|---|---|---|---|---|---|---|
Roseolovirus | Humans | T-cells; B-cells; NK-cell; monocytes; macrophages; epithelial | Glycoprotiens | Budding | Nucleus | Nucleus | Respiratory contact |
Cytomegalovirus | Humans; monkeys | Epithelial mucosa | Glycoprotiens | Budding | Nucleus | Nucleus | Urine; saliva |
Proboscivirus | Elephants | None | Glycoprotiens | Budding | Nucleus | Nucleus | Contact |
Muromegalovirus | Rodents | Salivary glands | Glycoprotiens | Budding | Nucleus | Nucleus | Contact |
Human health
There are four known member species of the Betaherpesvirinae subfamily that are infectious for humans:
- Human cytomegalovirus(HCMV), also known as Human herpesvirus 5 (HHV-5),
- Human herpesvirus 6A and 6B (HHV-6A and HHV-6B), which were classified as distinct species in 2012,[4]
- Human herpesvirus 7(HHV-7)
Human cytomegalovirus (HCMV, HHV-5) "seems to have a large impact on immune parameters in later life and may contribute to increased morbidity and eventual mortality."
References
External links
- Betaherpesvirinae at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
- Viralzone: Betaherpesvirinae
- ICTV