HDV-Like Viruses

Abstract

Hepatitis delta virus (HDV) is a defective human virus that lacks the ability to produce its own envelope proteins and is thus dependent on the presence of a helper virus, which provides its surface proteins to produce infectious particles. Hepatitis B virus (HBV) was so far thought to be the only helper virus described to be associated with HDV. However, recent studies showed that divergent HDV-like viruses could be detected in fishes, birds, amphibians, and invertebrates, without evidence of any HBV-like agent supporting infection. Another recent study demonstrated that HDV can be transmitted and propagated in experimental infections ex vivo and in vivo by different enveloped viruses unrelated to HBV, including hepatitis C virus (HCV) and flaviviruses such as Dengue and West Nile virus. All this new evidence, in addition to the identification of novel virus species within a large range of hosts in absence of HBV, suggests that deltaviruses may take advantage of a large spectrum of helper viruses and raises questions about HDV origins and evolution.

Hepatitis D virus-induced interferon response and administered interferons control cell division-mediated virus spread

“…Our findings may explain the long-term HDV persistence in patients (>1 year) with liver transplantation and anti-HBsAg therapy, 9,10 and in HDV mono-infected mice (>6 weeks) with transplanted PHHs. 11 Moreover, a number of HDV-like agents were discovered recently from vertebrates and invertebrates (reviewed in 22 ). Most of these agents are not associated with hepadnaviruses and do not encode L-HDAg homologs with prenylation moieties.…”

Hepatitis D: advances and challenges

“…[ 18 ] This strongly indicates that HDV has a much longer evolutionary history than previously anticipated, although the origin of HDV remains uncertain. [ 19 , 20 ]…”

“…Recently, more HDV-like viruses (deltaviruses) have been discovered in a diverse range of hosts, including birds, [13] snakes, [14] rodents, [15] white-tailed deer, [16] Eastern woodchucks, [17] fish, amphibians, and even invertebrates [18] . This strongly indicates that HDV has a much longer evolutionary history than previously anticipated, although the origin of HDV remains uncertain [19,20] …”

“…[18] This strongly indicates that HDV has a much longer evolutionary history than previously anticipated, although the origin of HDV remains uncertain. [19,20] Human HDV is a peculiar hepatic pathogen and is a defective RNA virus. It completely relies on cellular enzymes for genome replication and dependents on HBV for its propagation in hepatocytes.…”

Short ‘1.2× Genome’ Infectious Clone Initiates Kolmiovirid Replication in Boa constrictor Cells

“…Metatranscriptomic studies revealed more deltaviruses in common vampire bats, a lesser dog-like bat, whitetailed deer, eastern woodchuck, passerine birds, zebra finch, lantern fish, and amboli leaping frogs [20][21][22]. The recent findings have sparked deltavirus research and raised questions about the evolutionary origin of deltaviruses [23][24][25]. The identification of deltaviruses across several taxa led to the establishment of a new realm, Ribozyviria, with family Kolmioviridae including eight genera [26,27].…”