GB viruses
| GB viruses | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||||||||
|
||||||||||||||||||
| Taxonomic characteristics | ||||||||||||||||||
|
||||||||||||||||||
| Scientific name | ||||||||||||||||||
| GB virus | ||||||||||||||||||
| Short name | ||||||||||||||||||
| GBV | ||||||||||||||||||
| Left | ||||||||||||||||||
|
The GB viruses are a nontaxonomic group of enveloped single-stranded RNA viruses with positive polarity . They are now divided into four different species (A, B, C, D), which differ in terms of their host and their pathogenicity and are assigned to different genera within the Flaviviridae family . The designation GB is derived from the initials of the first patient in whom the virus was isolated in 1996. At that time, isolation in humans was wrongly associated with hepatitis , which is where the old name hepatitis G virus (HGV) comes from. Since very similar viruses (GBV-A and GBV-B) were discovered in monkeys, the human variant has been referred to as GB virus C (GBV-C).
GB virus A
The GB-A virus (GBV-A) was dissolved in six species of New World monkeys found, inter alia, in tamarins of the genus Saguinus . They do not cause hepatitis, even when infected primates that are not naturally infected. GBV-A can be transmitted experimentally through blood, but the natural route of transmission is unknown. Compared to the hepaciviruses, the genome of GBV-A completely lacks the gene for a capsid protein . It is assigned to the genus Pegivirus as pegivirus A.
GB virus B
The GB virus B (GBV-B) is closely related to the hepatitis C virus (officially Hepacivirus C , HCV), but is still clearly differentiated as a separate virus species. As Hepacivirus B, GBV-B is also assigned to the genus Hepacivirus . Like GBV-A, it was found in New World monkeys (also tamarins of the genus Saguinus) and in chimpanzees . So far only one GBV-B isolate has been found, which causes short-term, self-limiting hepatitis in tamarins and owl monkeys .
GB virus C
The GB virus C (GBV-C) is also present in humans. It is assigned to the genus Pegivirus as Pegivirus C (formerly Human pegivirus , HPgV) . In 1996, the GBV-C was mistakenly viewed as an independent pathogen of a so-called hepatitis G (HGV). The 9.4 kb RNA genome has an open reading frame (ORF) which codes for the envelope proteins E1 and E2 and for the non-structural proteins NS2, NS3, NS4A, NS4B, NS5A and NS5B .
GBV-C infection in humans is somewhat more common with hepatitis C infection and is particularly common among drug addicts. It is unclear what significance this virus has in humans, as it is considered unlikely to cause a disease on its own. The infection is certainly not associated with a hepatitis infection, as was initially assumed.
The only clinical effect that could be shown is that HIV-infected people in whom GBV-C is undetectable show a higher level of HIV replication than those in whom GBV-C is present. So it looks like HIV patients with GBV-C have a longer life expectancy than those without GBV-C, but the observed effect could be due to other differences as well. The mechanism of this suppressive effect of GBV-C on HIV is completely unexplained. Active research is currently underway into the effects of the virus on the immune system in patients co-infected with GBV-C and HIV.
GB virus Citro
GBV-Citro is a subtype of Pegivirus C and infects chimpanzees.
GB virus D
The GB virus D (GBV-D) infected bats and is as Pegivirus B together with GBV-A and C in the genus Pegivirus provided.
transmission
The GB viruses are transmitted via blood and blood products and possibly via contact infection or smear infection .
diagnosis
A commercial test briefly existed to detect the specific antibodies, but was withdrawn from the market after a connection with hepatitis was disproved. The virus RNA of the GBV-C can be detected in special laboratories for scientific questions.
Web links
Individual evidence
- ↑ ICTV Master Species List 2018b.v2 . MSL # 34, March 2019
- ↑ a b c d ICTV: ICTV Taxonomy history: Yellow fever virus , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
- ↑ Omar Bagasra, Muhammad Sheraz, Donald Gene Pace: Hepatitis G Virus or GBV-C: A Natural Anti-HIV Interfering Virus . In: Witzany, G. (ed). Viruses: Essential Agents of Life. Springer, Dordrecht (2012), pp. 363–388.
- ↑ a b c d J. T. Stapleton, S. Foung, AS Muerhoff, J. Bukh, P. Simmonds: The GB viruses: A review and proposed classification of GBV-A, GBV-C (HGV), and GBV-D in genus Pegivirus within the family Flaviviridae . In: Journal of General Virology . 92, No. 2, 2010, pp. 233-46. doi : 10.1099 / vir.0.027490-0 . PMID 21084497 . PMC 3081076 (free full text).
- ↑ TP Leary, SM Desai, JC Erker, IK Mushahwar: The sequence and genomic organization of a GB virus A variant isolated from captive tamarins . In: Journal of General Virology , 1997, 78.9, pp. 2307-2313
- ↑ J Bukh, CL Apgar, S Govindarajan, RH Purcell: Host range studies of GB virus-B hepatitis agent, the closest relative of hepatitis C virus, in New World monkeys and chimpanzees . In: Journal of Medical Virology , 2001, 65 (4), pp. 694-697
- ↑ HL Tillmann, H Heiken et al. : Infection with GB virus C and reduced mortality among HIV-infected patients . In: New England Journal of Medicine , 2001, 345 (10), pp. 715-724
- ↑ Xiang J, George SL, Wünschmann S, et al. : Inhibition of HIV-1 replication by GB virus C infection through increases in RANTES, MIP-1alpha, MIP-1beta, and SDF-1 . In: Lancet . 363, No. 9426, 2004, pp. 2040-6. doi : 10.1016 / S0140-6736 (04) 16453-2 . PMID 15207954 .
- ↑ Mosam A, Sathar MA, Dawood H, Cassol E, Esterhuizen TM, Coovadia HM: Effect of GB Virus C Co-infection on Response to Generic HAART in African Patients with HIV-1 Clade C Infection . In: AIDS . 21, No. 10, 2007, pp. 1377-9. doi : 10.1097 / QAD.0b013e3281532cb8 . PMID 17545721 .
- ↑ Jung S, Eichenmüller M, Donhauser N, et al. : HIV entry inhibition by the envelope glycoprotein of 2 GB virus C . In: AIDS . 21, No. 5, 2007, pp. 645-7. doi : 10.1097 / QAD.0b013e32803277c7 . PMID 17314528 .
- ↑ a b ICTV : Positive-sense RNA Viruses: Flaviviridae, Genus: Pegivirus , 2019