• AIDS
  • used to indicate that an individual has been infected with the human immunodeficiency virus but does not yet have AIDS. (thefreedictionary.com)
  • Because foreign virus antigens are expressed in these tumors, persons who are immunosuppressed such as AIDS or transplant patients are at higher risk for these types of cancers. (wikipedia.org)
  • study of SIVcpz in wild living chimpanzees suggests that infected chimpanzees experience an AIDS-like illness similar to HIV-1 infected humans. (wikipedia.org)
  • The discovery of SIV was made shortly after HIV-1 had been isolated as the cause of AIDS and led to the discovery of HIV-2 strains in West Africa. (wikipedia.org)
  • The discovery of the virus itself occurred two years following the report of the first major cases of AIDS-associated illnesses. (wikipedia.org)
  • Results of research on wild chimpanzees in Cameroon indicate that they are naturally infected with the simian foamy virus and constitute a reservoir of HIV-1, a precursor of the acquired immunodeficiency syndrome (AIDS) in humans. (wikipedia.org)
  • Human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV). (wikipedia.org)
  • Although most HIV-1 infected individuals have a detectable viral load and in the absence of treatment will eventually progress to AIDS, a small proportion (about 5%) retain high levels of CD4+ T cells (T helper cells) without antiretroviral therapy for more than 5 years. (wikipedia.org)
  • However, reviews of the epidemiological evidence of early HIV-1 infection in stored blood samples, and of old cases of AIDS in Central Africa, have led many scientists to believe that HIV-1 group M early human center was probably not in Cameroon, but rather farther south in the Democratic Republic of the Congo, more probably in its capital city, Kinshasa (formerly Léopoldville). (wikipedia.org)
  • viral
  • When a complete virus particle ( virion ) comes in contact with a host cell, only the viral nucleic acid and, in some viruses, a few enzymes are injected into the host cell. (thefreedictionary.com)
  • Within the host cell the genetic material of a DNA virus is replicated and transcribed into messenger RNA by host cell enzymes, and proteins coded for by viral genes are synthesized by host cell ribosomes. (thefreedictionary.com)
  • Some of these may already have been present within the initial virus, and others may be coded for by the viral genome for production within the host cell. (thefreedictionary.com)
  • Because host cells do not have the ability to replicate "viral RNA" but are able to transcribe messenger RNA, RNA viruses must contain enzymes to produce genetic material for new virions. (thefreedictionary.com)
  • For certain viruses the RNA is replicated by a viral enzyme ( transcriptase ) contained in the virion, or produced by the host cell using the viral RNA as a messenger. (thefreedictionary.com)
  • In other viruses a reverse transcriptase contained in the virion transcribes the genetic message on the viral RNA into DNA, which is then replicated by the host cell. (thefreedictionary.com)
  • In viruses that have membranes, membrane-bound viral proteins are synthesized by the host cell and move, like host cell membrane proteins, to the cell surface. (thefreedictionary.com)
  • The viral Gag polyprotein targets the plasma membrane and is the orchestrator of the HIV assembly as its expression is sufficient to promote the formation of virus-like particles carrying a lipidic envelope derived from the host cell membrane. (frontiersin.org)
  • In addition, host cell factors are required for proper trafficking of the viral constituents, as well as for virus assembly and budding. (frontiersin.org)
  • Viral assembly requires Gag-Gag interactions that can occur at different levels: MA-MA interactions upon MA-membrane interactions, CA-CA interactions and NC-NC interactions via the genomic RNA (gRNA) (Figure 1 ). (frontiersin.org)
  • Other viruses, however, such as the herpesviruses , actually enter a time known as "viral latency," when little or no replication is taking place until further replication is initiated by a specific trigger. (thefreedictionary.com)
  • In CFS blood samples, XMRV was readily detected by PCR amplification of the viral genome, by the expression of viral antigens in infected cells and by virus isolation and propagation in cell culture. (biomedcentral.com)
  • XMLV is carried by most strains of mice in the form of endogenous viral genomes integrated in the chromosomes of the mouse germ line and inherited as Mendelian traits, but that can be activated to emerge as potentially infectious virus particles. (biomedcentral.com)
  • The tropism of the viruses (that is, the cells and species they can infect) is largely determined by the cell surface receptors [ 9 ] to which the viral envelope glycoproteins bind before the virus gains entry into the cell. (biomedcentral.com)
  • This subset was homozygous for a mutation in the gene for RNase L, which is activated in response to the type 1 interferons, which are induced by viral infection and activate innate cellular anitviral defenses. (biomedcentral.com)
  • Although viral architecture is very complex, every virus contains at least a genome and a capsid.Most animal viruses are also surrounded by a lipid envelope, a bilayered membrane analogous to a cell membrane. (thefreedictionary.com)
  • Initiation of HAART in drug-naive HIV type 1 patients prevents viral breakthrough for a median period of 35.5 months in 60% of the patients. (nih.gov)
  • Once integrated, HTLV-1 continues to exist only as a provirus which can spread from cell to cell through a viral synapse. (wikipedia.org)
  • Chronic indirect tumor viruses, on the other hand, can be lost (at least theoretically) from a mature tumor that has accumulated sufficient mutations and growth conditions (hyperplasia) from the chronic inflammation of viral infection. (wikipedia.org)
  • After binding to molecules on the cell surface, the virion is endocytosed and enters the endoplasmic reticulum - a behavior unique among known non-enveloped viruses - where the viral capsid structure is likely to be disrupted by action of host cell disulfide isomerase enzymes. (wikipedia.org)
  • HIV-1 is composed of two copies of noncovalently linked, unspliced, positive-sense single-stranded RNA enclosed by a conical capsid composed of the viral protein p24, typical of lentiviruses. (wikipedia.org)
  • The so-called SOSIP trimers not only reproduce the antigenic properties of the native viral spike but also display the same degree of immature glycans as presented on the native virus. (wikipedia.org)
  • Using HIV-1 sequences preserved in human biological samples along with estimates of viral mutation rates, scientists calculate that the jump from chimpanzee to human probably happened during the late 19th or early 20th century, a time of rapid urbanisation and colonisation in equatorial Africa. (wikipedia.org)
  • closely related
  • Such a doublet is also observed in cells infected with simian immunodeficiency virus (SIV), a virus closely related to HIV-2. (google.es)
  • Research after Segal's theory shows that HIV is much more closely related to the simian immunodeficiency virus than to any other virus. (wikipedia.org)
  • The only human genotype that does not have a simian relative is A. It is thought that genotypes B, D, E, F and G originated in Africa from closely related STLV about 30,000 years ago, while the Asian genotype C is thought to have originated independently in Indonesia from the simians present there. (wikipedia.org)
  • The pandemic strain of HIV-1 is closely related to a virus found in chimpanzees of the subspecies Pan troglodytes troglodytes, which live in the forests of the Central African nations of Cameroon, Equatorial Guinea, Gabon, Republic of Congo (or Congo-Brazzaville), and Central African Republic. (wikipedia.org)
  • In particular, each of the known HIV-1 strains is either closely related to the SIV that infects the chimpanzee subspecies Pan troglodytes troglodytes (SIVcpz) or closely related to the SIV that infects western lowland gorillas (Gorilla gorilla gorilla), called SIVgor. (wikipedia.org)
  • The pandemic HIV-1 group M is most closely related to the SIVcpz collected from the southeastern rain forests of Cameroon (modern East Province) near the Sangha River. (wikipedia.org)
  • endemic
  • The pandemic HIV-1 strain (group M or Main) and a rare strain found only in a few Cameroonian people (group N) are clearly derived from SIVcpz strains endemic in Pan troglodytes troglodytes chimpanzee populations living in Cameroon. (wikipedia.org)
  • International Committ
  • This is a taxonomic list of viruses according to the most recent (2014) taxonomy release by the International Committee on Taxonomy of Viruses (ICTV), placed into the groups of the Baltimore classification system. (wikipedia.org)
  • International Committee on Taxonomy of Viruses. (wikipedia.org)
  • As of the most recent (2016) taxonomy release by the International Committee on Taxonomy of Viruses, there were 77 recognized species in this family contained within four genera, as well as three species that could not be assigned to a genus. (wikipedia.org)
  • 1978
  • Yap and Ada, "Transfer of specific sytitoxic T lymphocytes protects mice inoculated with influenza virus," Nature 273: 238-239, 1978. (patentgenius.com)
  • genome
  • Other viruses are only carcinogenic when they integrate into the host cell genome as part of a biological accident, such as polyomaviruses and papillomaviruses. (wikipedia.org)
  • The genome and proteins of HIV (human immunodeficiency virus) have been the subject of extensive research since the discovery of the virus in 1983. (wikipedia.org)
  • The complete sequence of the HIV-1 genome, extracted from infectious virions, has been solved to single-nucleotide resolution. (wikipedia.org)
  • influenza
  • Construction of live vaccines by using genetically engineered poxviruses: Biological activity of recombinant vaccinia virus expressing influenza virus hemagglutinin," Proc. (patentgenius.com)
  • As experiences with HIV-1 and new variants of influenza A (and also with novel animal pathogens such as canine parvovirus [ 4 ]) show, this shift can occur rapidly, over time scales of decades, years or even months. (royalsocietypublishing.org)
  • Moreover, we recognize that 'species' itself is an imprecise designation, especially for viruses such as influenza A where different serotypes can have very different epidemiologies and health impacts. (royalsocietypublishing.org)
  • 1]. Other areas of research include chronic progressive lymphedema in horses and H1N1 influenza. (wikipedia.org)
  • 1983
  • J. Med 309(1): 13-17, 1983. (patentgenius.com)
  • Elder, J.H., and J.I. Mullins (1983) Nucleotide sequence of the envelope gene of Gardner-Arnstein feline leukemia virus B reveals unique sequence homologies with a murine mink cell focus-forming virus. (springer.com)
  • glycoproteins
  • As the only proteins on the surface of the virus, the envelope glycoproteins (gp120 and gp41) are the major targets for HIV vaccine efforts. (wikipedia.org)
  • strains
  • Sabin and Boulger, "History o Sabin attenuated poliovirus oral live vaccine strains," Journal of Biological Standardization 1: 115-118, 1973. (patentgenius.com)
  • HIV-2 was more similar to the then-known SIV strains than to HIV-1, suggesting for the first time the simian origin of HIV. (wikipedia.org)
  • Further studies indicated that HIV-2 is derived from the SIVsmm strain found in sooty mangabeys, whereas HIV-1, the predominant virus found in humans, is derived from SIV strains infecting chimpanzees (SIVcpz). (wikipedia.org)
  • Another very rare HIV-1 strain (group P) is clearly derived from SIVgor strains of Cameroon. (wikipedia.org)
  • Ebola
  • Some of the most virulent diseases are caused by viruses, e.g., the hemorrhagic fever caused by Ebola virus. (thefreedictionary.com)
  • Outbreaks of the Ebola virus in the Congo Basin and in Gabon in the 1990s have been associated with the butchering of apes and consumption of their meat. (wikipedia.org)
  • medical citation needed] The Ebola virus, for which the primary host is suspected to be fruit bats, has been linked to bushmeat. (wikipedia.org)
  • virions
  • Few, if any, free virions are produced and there is usually no detectable virus in the blood plasma though the virus is present in genital secretions. (wikipedia.org)
  • species
  • There are 219 virus species that are known to be able to infect humans. (royalsocietypublishing.org)
  • The first of these to be discovered was yellow fever virus in 1901, and three to four new species are still being found every year. (royalsocietypublishing.org)
  • Extrapolation of the discovery curve suggests that there is still a substantial pool of undiscovered human virus species, although an apparent slow-down in the rate of discovery of species from different families may indicate bounds to the potential range of diversity. (royalsocietypublishing.org)
  • Indeed, a substantial proportion of mammalian viruses may be capable of crossing the species barrier into humans, although only around half of these are capable of being transmitted by humans and around half again of transmitting well enough to cause major outbreaks. (royalsocietypublishing.org)
  • New species of human virus are still being identified, at a rate of three or four per year (see below), and viruses make up over two-thirds of all new human pathogens [ 2 ], a highly significant over-representation given that most human pathogen species are bacteria, fungi or helminths. (royalsocietypublishing.org)
  • Nonetheless, a study of currently recognized 'species' is a natural starting point for attempts to characterize and interpret patterns of virus diversity. (royalsocietypublishing.org)
  • avian
  • Many specialist human viruses also have mammalian or avian origins. (royalsocietypublishing.org)
  • 1908: Vilhelm Ellerman and Olaf Bang, University of Copenhagen, first demonstrated that avian sarcoma leukosis virus could be transmitted after cell-free filtration to new chickens, causing leukemia. (wikipedia.org)
  • ICTV
  • Though not used by the ICTV, Baltimore classification, which groups viruses together based on how they produce mRNA, is used in conjunction with the ICTV's work in modern virus classification. (wikipedia.org)
  • Developments in plant virus taxonomy since the publication of the 6th ICTV Report. (wikipedia.org)
  • lipid envelope
  • Although in general viruses "steal" their lipid envelope from the host cell, virtually all of them produce "envelope proteins" that penetrate the envelope and serve as receptors. (thefreedictionary.com)
  • particles
  • Poiesz, B.J., R.W. Ruscetti, A.F. Gazdar, P.A. Bunn, J.D. Minna, and R.C. Gallo (1980) Detection and isolation of type C virus particles from fresh and cultured lymphocytes of a patient with cutaneous T-cell lymphoma. (springer.com)
  • envelope
  • On the other hand, the envelope glycoprotein precursor of HIV-1 does not form a dimer during its processing. (google.es)
  • 1. A purified antigenic composition comprising one or more envelope proteins selected from gp300 of HIV-2, p200 of HIV-2, p90/80 of HIV-2, gp300 of SIV, and gp140 of HIV-2. (google.es)
  • infectivity
  • While various sub-groups of the virus acquired human infectivity at different times, the global pandemic had its origins in the emergence of one specific strain - HIV-1 subgroup M - in Léopoldville in the Belgian Congo (now Kinshasa in the Democratic Republic of the Congo) in the 1920s. (wikipedia.org)
  • tropism
  • However, in general virus-cell interactions are mediated by commonly occurring molecules on the cell surface, and therefore are likely not a major contributor to individual viruses' observed cell-type tropism. (wikipedia.org)
  • replication
  • Because these properties are shared by certain bacteria ( rickettsiae , chlamydiae ), viruses are now characterized by their simple organization and their unique mode of replication. (thefreedictionary.com)
  • HIV-1 has two important regulatory elements: Tat and Rev and few important accessory proteins such as Nef, Vpr, Vif and Vpu which are not essential for replication in certain tissues. (wikipedia.org)
  • 1984
  • 1984). To date, two related but distinct viruses, HIV-1 and HIV-2, have been identified (Barre-Sinoussi et al. (google.es)
  • sooty
  • HIV-2 is less transmittable and is largely confined to West Africa, along with its closest relative, a virus of the sooty mangabey (Cercocebus atys atys), an Old World monkey inhabiting southern Senegal, Guinea-Bissau, Guinea, Sierra Leone, Liberia, and western Ivory Coast. (wikipedia.org)
  • isolation
  • Isolation and Characterization of Acyclovir-resistant Mutants of Herpes Simplex Virus," Journal of General Virology 49:115-124, 1980. (patentgenius.com)
  • Firstly, this is because viruses cannot truly be isolated in pure culture-even stringent isolation techniques cannot exclude undetected contaminating viruses with similar density characteristics, and viruses must be grown on cells. (wikipedia.org)