page_title: Gibbon ape leukemia virus
section_title: History
hierarchical_section_title: Gibbon ape leukemia virus / Epizootiology / History
caption_attribution_description: Gibbon-ape leukemia virus Phylogenetic tree
context_page_description: Gibbon-ape leukemia virus is an oncogenic, type C retrovirus that has been isolated from primate neoplasms, including the white-handed gibbon and woolly monkey. The virus was identified as the etiological agent of hematopoietic neoplasms, leukemias, and immune deficiencies within gibbons in 1971, during the epidemic of the late 1960s and early 1970s. Epidemiological research into the origins of GaLV has developed two hypotheses for the virus' emergence. These include cross-species transmission of the retrovirus present within a species of East Asian rodent or bat, and the inoculation or blood transfusion of a MbRV-related virus into captured gibbons populations housed at medical research institutions. The virus was subsequently identified in captive gibbon populations in Thailand, the US and Bermuda.
  GaLV is transmitted horizontally by contact with excretory products of infected gibbons. However, it is also hypothesised to be vertically transmitted via parent-progeny transmission. Phylogenetic analysis have revealed 7 strains of GaLV; GaLV-SF, GaLV-SEATO, GaLV-BR, GALV-X, GaLV-Mar, GaLV-H and SSV, which have emerged as a result of selection pressures from the host immune system.
context_section_description: Cases of malignant lymphomas and leukemias were not described in gibbons until the 1960s, when several cases of haematopoietic neoplasia were reported in a single colony of white-handed gibbons housed at the SEATO research facility in Bangkok, Thailand. In 1971, phylogenetic analysis of the Leukemia-inducing retrovirus, lead to the identification of GaLV-SEATO, published within De Paoli et al. (1971). Following this discovery, five other strains of GaLV was identified from animals whose associated neoplastic syndromes were exclusively recorded in captive gibbon populations, which include:
  GaLV-SF: identified from a gibbon lymphosarcoma in San Francisco and within captured gibbons populations at the University of California San Francisco Medical Center and the University of California. (Kawakami et al. and Snyder et al., 1973)
  GALV‐X: detected in cell culture from a human T-cell line infected with HIV-1 in Louvain, Belgium and at the National Cancer Institute in Maryland, US.
  GALV‐H: identified from a gibbon with lymphocytic leukemias from a colony of free-ranging gibbons at the Hall's Island, Bermuda.
  GALV‐Br: Identified in frozen brain samples of non-leukemic gibbons at the Gulf South Research Institute in Louisiana. (Gallo et al., 1978)
  GaLV-Mar: detected in cell culture (in vitro) derived from marmoset cells.
  Simian sarcoma (SSV): a defective GALV recombinant, derived from a single isolate of fibrosarcoma in a Woolly Monkey that was exposed to a GALV-infected captive gibbon. For viral replication to occur within the host, simian sarcoma-associated virus (SSAV) must also be present.
  These strains exhibit high genetic similarity, demonstrated through DNA sequencing which reveals approx. 90% sequence identity and more than 93% amino acid genome identity between strains of GaLV. Differences between these strains occurs in the env gene, with divergence ranging from 85% to 99%.
caption: GaLV Phylogenetic trees derived from genome sequences of GaLV strains; GaLV-SEATO, GaLV-Br, GaLV-H, GaLV-X and GaLV-SF.
exif: {}