The human immunodeficiency viruses (HIV) are two species of Lentivirus that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive. Without treatment, average survival time after infection with HIV is estimated to be 9 to 11 years, depending on the HIV subtype.
A retrovirus is a type of virus that inserts a DNA copy of its RNA genome into the DNA of a host cell that it invades, thus changing the genome of that cell. After invading a host cell's cytoplasm, the virus uses its own reverse transcriptase enzyme to produce DNA from its RNA genome, the reverse of the usual pattern, thus retro (backwards). The new DNA is then incorporated into the host cell genome by an integrase enzyme, at which point the retroviral DNA is referred to as a provirus. The host cell then treats the viral DNA as part of its own genome, transcribing and translating the viral genes along with the cell's own genes, producing the proteins required to assemble new copies of the virus. Many retroviruses cause serious diseases in humans, other mammals, and birds.
Retroviral integrase (IN) is an enzyme produced by a retrovirus that integrates—forms covalent links between—its genetic information into that of the host cell it infects. Retroviral INs are not to be confused with phage integrases (recombinases) used in biotechnology, such as λ phage integrase, as discussed in site-specific recombination.
The genome and proteins of HIV (human immunodeficiency virus) have been the subject of extensive research since the discovery of the virus in 1983. "In the search for the causative agent, it was initially believed that the virus was a form of the Human T-cell leukemia virus (HTLV), which was known at the time to affect the human immune system and cause certain leukemias. However, researchers at the Pasteur Institute in Paris isolated a previously unknown and genetically distinct retrovirus in patients with AIDS which was later named HIV." Each virion comprises a viral envelope and associated matrix enclosing a capsid, which itself encloses two copies of the single-stranded RNA genome and several enzymes. The discovery of the virus itself occurred two years following the report of the first major cases of AIDS-associated illnesses.
Transcription factor Sp1, also known as specificity protein 1* is a protein that in humans is encoded by the SP1 gene.
Chemokine ligand 5 is a protein which in humans is encoded by the CCL5 gene. The gene has been discovered in 1990 by in situ hybridisation and it is localised on 17q11.2-q12 chromosome. It is also known as RANTES. RANTES was first described by Dr. Tom Schall who named the protein, the original source of the name Rantes was from the Argentine movie Man Facing Southeast about an alien who shows up in a mental ward who was named Rantés, the rather clunky acronym was only made to fit the name.
Simian foamy virus (SFV) is a species of the genus Spumavirus that belongs to the family of Retroviridae. It has been identified in a wide variety of primates, including prosimians, New World and Old World monkeys, as well as apes, and each species has been shown to harbor a unique (species-specific) strain of SFV, including African green monkeys, baboons, macaques, and chimpanzees. As it is related to the more well-known retrovirus human immunodeficiency virus (HIV), its discovery in primates has led to some speculation that HIV may have been spread to the human species in Africa through contact with blood from apes, monkeys, and other primates, most likely through bushmeat-hunting practices.
A long terminal repeat (LTR) is a pair of identical sequences of DNA, several hundred base pairs long, which occur in eukaryotic genomes on either end of a series of genes or pseudogenes that form a retrotransposon or an endogenous retrovirus or a retroviral provirus. All retroviral genomes are flanked by LTRs, while there are some retrotransposons without LTRs. Typically, an element flanked by a pair of LTRs will encode a reverse transcriptase and an integrase, allowing the element to be copied and inserted at a different location of the genome. Copies of such an LTR-flanked element can often be found hundreds or thousands of times in a genome. LTR retrotransposons comprise about 8% of the human genome.
Visna-maedi virus from the genus Lentivirus and subfamily Orthoretrovirinae, is a retrovirus that causes encephalitis and chronic pneumonitis in sheep. It is known as visna when found in the brain, and maedi when infecting the lungs. Lifelong, persistent infections in sheep occur in the lungs, lymph nodes, spleen, joints, central nervous system, and mammary glands; The condition is sometimes known as ovine progressive pneumonia (OPP), particularly in the United States, or Montana sheep disease. White blood cells of the monocyte/macrophage lineage are the main target of the virus.
Antibody-dependent enhancement (ADE), sometimes less precisely called immune enhancement or disease enhancement, is a phenomenon in which binding of a virus to suboptimal antibodies enhances its entry into host cells, followed by its replication. The suboptimal antibodies can result from natural infection or from vaccination. ADE may cause enhanced respiratory disease, but is not limited to respiratory disease. It has been observed in HIV, RSV virus and Dengue virus and is monitored for in vaccine development.
Importin subunit alpha-6 is a protein that in humans is encoded by the KPNA5 gene.
Cullin-4A is a protein that in humans is encoded by the CUL4A gene. CUL4A belongs to the cullin family of ubiquitin ligase proteins and is highly homologous to the CUL4B protein. CUL4A regulates numerous key processes such as DNA repair, chromatin remodeling, spermatogenesis, haematopoiesis and the mitotic cell cycle. As a result, CUL4A has been implicated in several cancers and the pathogenesis of certain viruses including HIV. A component of a CUL4A complex, Cereblon, was discovered to be a major target of the teratogenic agent thalidomide.
G2/mitotic-specific cyclin-B2 is a protein that in humans is encoded by the CCNB2 gene.
Serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit beta isoform is an enzyme that in humans is encoded by the PPP2R5B gene.
Serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit epsilon isoform is an enzyme that in humans is encoded by the PPP2R5E gene.
SAM domain and HD domain-containing protein 1 is a protein that in humans is encoded by the SAMHD1 gene. SAMHD1 is a cellular enzyme, responsible for blocking replication of HIV in dendritic cells, macrophages, monocytes and resting CD4+ T lymphocytes. It is an enzyme that exhibits phosphohydrolase activity, converting deoxynucleoside triphosphates (dNTPs) to inorganic phosphate (iPPP) and a 2'-deoxynucleoside (i.e. deoxynucleosides without a phosphate group). In doing so, SAMHD1 depletes the pool of dNTPs available to a reverse transcriptase for viral cDNA synthesis and thus prevents viral replication. SAMHD1 has also shown nuclease activity. Although a ribonuclease activity was described to be required for HIV-1 restriction, recent data confirmed that SAMHD1-mediated HIV-1 restriction in cells does not involve ribonuclease activity.
Protein VPRBP is a protein that in humans is encoded by the VPRBP gene.
AIDS is caused by the human immunodeficiency virus (HIV). Individuals with HIV have what is referred to as a "HIV infection". When infected semen, vaginal secretions, or blood come in contact with the mucous membranes or broken skin of an uninfected person, HIV may be transferred to the uninfected person, causing another infection. Additionally, HIV can also be passed from infected pregnant women to their uninfected baby during pregnancy and/or delivery, or via breastfeeding. As a result of HIV infection, a portion of these individuals will progress and go on to develop clinically significant AIDS.
Interferon alpha-16, also known as IFN-alpha-16, is a protein that in humans is encoded by theIFNA16 gene.
Vpx is a virion-associated protein encoded by human immunodeficiency virus type 2 HIV-2 and most simian immunodeficiency virus (SIV) strains, but that is absent from HIV-1. It is similar in structure to the protein Vpr that is carried by SIV and HIV-2 as well as HIV-1. Vpx is one of five accessory proteins carried by lentiviruses that enhances viral replication by inhibiting host antiviral factors.
