Rhadinovirus

The genus consists of the following 12 species:[2]

• Ateline gammaherpesvirus 2
• Ateline gammaherpesvirus 3
• Bovine gammaherpesvirus 4
• Cricetid gammaherpesvirus 2
• Human gammaherpesvirus 8
• Macacine gammaherpesvirus 5
• Macacine gammaherpesvirus 8
• Macacine gammaherpesvirus 11
• Macacine gammaherpesvirus 12
• Murid gammaherpesvirus 4
• Murid gammaherpesvirus 7
• Saimiriine gammaherpesvirus 2

In general, rhadinoviruses infect lymphocytes and adherent cells, such as fibroblasts, epithelial cells, and endothelial cells and once infection occurs, it is, in general, lifelong. Rhandinoviruses infect a wide range of mammals, include humans. Rhadinoviruses have been found in New World monkeys such as the squirrel monkeys (herpesvirus saimiri) and in mice (Murid gammaherpesvirus 68). More recently, both KSHV-like viruses and a new form of rhadinovirus called rhesus rhadinovirus have been discovered in Old World monkeys. These findings suggest that an additional human tumor virus related to KSHV may be found in humans.

Viruses in Rhadinovirus 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 180kb in length.[1] They are large double-stranded viruses that possess up to 100 genes in a single long chromosome, which is flanked by repetitive DNA sequences called terminal repeats.

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. Humans and other mammals serve as natural hosts. Transmission routes are sexual, contact, and through saliva.[1]

Rhadinoviruses are unique because they have mastered the ability to pirate cellular genes from their host cells and incorporate them into their genomes. For example, most rhadinoviruses have a copy of the cyclin gene, which regulates the ability of the cell to divide. These viruses tend to cause tumors when infection occurs outside of their native hosts or in the case of KSHV, in humans when the host is immunosuppressed due to AIDS, old age, or in the setting of organ transplantation.

Wikimedia Commons has media related to Rhadinovirus.

Wikispecies has information related to Rhadinovirus.

• Virus Pathogen Database and Analysis Resource (ViPR): Herpesviridae
• Viralzone: Rhadinovirus
• ICTV