Kaposi's sarcoma-associated herpesvirus (KSHV) is the ninth known human herpesvirus; its formal name according to the International Committee on Taxonomy of Viruses (ICTV) is Human gammaherpesvirus 8, or HHV-8 in short. Like other herpesviruses, its informal names are used interchangeably with its formal ICTV name. This virus causes Kaposi's sarcoma, a cancer commonly occurring in AIDS patients, as well as primary effusion lymphoma, HHV-8-associated multicentric Castleman's disease and KSHV inflammatory cytokine syndrome. It is one of seven currently known human cancer viruses, or oncoviruses. Even after many years since the discovery of KSHV/HHV8, there is no known cure for KSHV associated tumorigenesis.
An oncovirus or oncogenic virus is a virus that can cause cancer. This term originated from studies of acutely transforming retroviruses in the 1950–60s, when the term "oncornaviruses" was used to denote their RNA virus origin. With the letters "RNA" removed, it now refers to any virus with a DNA or RNA genome causing cancer and is synonymous with "tumor virus" or "cancer virus". The vast majority of human and animal viruses do not cause cancer, probably because of longstanding co-evolution between the virus and its host. Oncoviruses have been important not only in epidemiology, but also in investigations of cell cycle control mechanisms such as the retinoblastoma protein.
Patrick S. Moore is an Irish and American virologist and epidemiologist who co-discovered together with his wife, Yuan Chang, two different human viruses causing the AIDS-related cancer Kaposi's sarcoma and the skin cancer Merkel cell carcinoma. The couple met while in medical school together and were married in 1989 while they pursued fellowships at different universities.
Yuan Chang is a Taiwanese-American virologist and pathologist who co-discovered together with her husband, Patrick S. Moore, the Kaposi's sarcoma-associated herpesvirus (KSHV) and Merkel cell polyomavirus, two of the seven known human oncoviruses.
HHV Latency Associated Transcript is a length of RNA which accumulates in cells hosting long-term, or latent, Human Herpes Virus (HHV) infections. The LAT RNA is produced by genetic transcription from a certain region of the viral DNA. LAT regulates the viral genome and interferes with the normal activities of the infected host cell.
Herpesviridae is a large family of DNA viruses that cause infections and certain diseases in animals, including humans. The members of this family are also known as herpesviruses. The family name is derived from the Greek word ἕρπειν, referring to spreading cutaneous lesions, usually involving blisters, seen in flares of herpes simplex 1, herpes simplex 2 and herpes zoster (shingles). In 1971, the International Committee on the Taxonomy of Viruses (ICTV) established Herpesvirus as a genus with 23 viruses among four groups. As of 2020, 115 species are recognized, all but one of which are in one of the three subfamilies. Herpesviruses can cause both latent and lytic infections.
Gammaherpesvirinae is a subfamily of viruses in the order Herpesvirales and in the family Herpesviridae. Viruses in Gammaherpesvirinae are distinguished by reproducing at a more variable rate than other subfamilies of Herpesviridae. Mammals serve as natural hosts. There are 43 species in this subfamily, divided among 7 genera with three species unassigned to a genus. Diseases associated with this subfamily include: HHV-4: infectious mononucleosis. HHV-8: Kaposi's sarcoma.
Viral entry is the earliest stage of infection in the viral life cycle, as the virus comes into contact with the host cell and introduces viral material into the cell. The major steps involved in viral entry are shown below. Despite the variation among viruses, there are several shared generalities concerning viral entry.
This family represents the Kaposi's sarcoma-associated herpesvirus (KSHV) internal ribosome entry site (IRES) present in the vCyclin gene. The vCyclin and vFLIP coding sequences are present on a bicistronic transcript and it is thought the IRES may initiate translation of vFLIP from this bicistronic transcript.
The mir-BHRF1-1 microRNA precursor found in Human herpesvirus 4 and Cercopithicine herpesvirus 15. In Epstein–Barr virus, mir-BHRF1-1 is found in the 5' UTR of the BHRF1 gene, which is known to encode a distant Bcl-2 homolog. The mature sequence is excised from the 5' arm of the hairpin. Two other miRNA precursors were found in this reading frame, namely Mir-BHRF1-2 and Mir-BHRF1-3.
The mir-BHRF1-2 microRNA precursor found in human herpesvirus 4, cercopithicine herpesvirus 15 and herpesvirus papio. In Epstein-Barr virus, mir-BHRF1-2 is found in the 3' UTR of the BHRF1 gene, which is known to encode a distant Bcl-2 homolog. The mature sequence is excised from the 3' arm of the hairpin. Two other miRNA precursors were found in this reading frame, namely Mir-BHRF1-1 and Mir-BHRF1-3.
The mir-BHRF1-3 microRNA precursor found in Human herpesvirus 4. In Epstein-Barr virus, mir-BHRF1-3 is found in the 3' UTR of the BHRF1 gene, which is known to encode a distant Bcl-2 homolog. The mature sequence is excised from the 5' arm of the hairpin. Two other miRNA precursors were found in this reading frame, namely Mir-BHRF1-1 and Mir-BHRF1-2.
Murid gammaherpesvirus 68 (MuHV-68) is an isolate of the virus species Murid gammaherpesvirus 4, a member of the genus Rhadinovirus. It is a member of the subfamily Gammaherpesvirinae in the family of Herpesviridae. MuHV-68 serves as a model for study of human gammaherpesviruses which cause significant human disease including B-cell lymphoma and Kaposi's sarcoma. The WUMS strain of MuHV-68 was fully sequenced and annotated in 1997, and the necessity of most of its genes in viral replication was characterized by random transposon mutagenesis.
The latency-associated nuclear antigen (LANA-1) or latent nuclear antigen is a Kaposi's sarcoma-associated herpesvirus (KSHV) latent protein initially found by Moore and colleagues as a speckled nuclear antigen present in primary effusion lymphoma cells that reacts with antibodies from patients with KS. It is the most immunodominant KSHV protein identified by Western-blotting as 222–234 kDa double bands migrate slower than the predicted molecular weight. LANA has been suspected of playing a crucial role in modulating viral and cellular gene expression. It is commonly used as an antigen in blood tests to detect antibodies in persons that have been exposed to KSHV.
Kaposi's sarcoma (KS) is a type of cancer that can form masses in the skin, in lymph nodes, in the mouth, or in other organs. The skin lesions are usually painless, purple and may be flat or raised. Lesions can occur singly, multiply in a limited area, or may be widespread. Depending on the sub-type of disease and level of immune suppression, KS may worsen either gradually or quickly. Except for Classical KS where there is generally no immune suppression, KS is caused by a combination of immune suppression and infection by Human herpesvirus 8.
MicroRNA 146a is a small non-coding RNA that in humans is encoded by the MIR146A gene.
Human herpes viruses, also known as HHVs, are part of a family of DNA viruses that cause several diseases in humans. One of the most notable functions of this virus family is their ability to enter a latent phase and lay dormant within animals for extended periods of time. The mechanism that controls this is very complex because expression of viral proteins during latency is decreased a great deal, meaning that the virus must have transcription of its genes repressed. There are many factors and mechanisms that control this process and epigenetics is one way this is accomplished. Epigenetics refers to persistent changes in expression patterns that are not caused by changes to the DNA sequence. This happens through mechanisms such as methylation and acetylation of histones, DNA methylation, and non-coding RNAs (ncRNA). Altering the acetylation of histones creates changes in expression by changing the binding affinity of histones to DNA, making it harder or easier for transcription machinery to access the DNA. Methyl and acetyl groups can also act as binding sites for transcription factors and enzymes that further modify histones or alter the DNA itself.
HSV epigenetics is the epigenetic modification of herpes simplex virus (HSV) genetic code.
Patricia Gail Spear is an American virologist. She is a professor emeritus of microbiology and immunology at Northwestern University in Evanston, Illinois. She is best known for her pioneering work studying the herpes simplex virus. Spear is a past president of the American Society for Virology and an elected member of the National Academy of Sciences.
Donald "Don" Emil Ganem is an American physician, virologist, professor emeritus of microbiology and medicine, and former global head of infectious disease research at Novartis Institutes for BioMedical Research (NIBR).
