UniProt release 8.7
Published September 19, 2006
The search for the origin of HIV-1
The origin of Human immunodeficiency virus 1 (HIV-1) has been the subject of hot debate for more than twenty years. In 1999, American, Japanese and French researchers claimed to have discovered an indisputable link between a chimpanzee virus from central West Africa called SIVcpz (Simian Immunodeficiency Virus from chimpanzees) and HIV-1. SIVcpz is 70-90% identical to HIV-1 and does not appear to cause illness in chimpanzees.
However, since SIVcpz was only found in a few chimpanzees held in captivity, the possibility existed that another yet unidentified species could be the natural reservoir of both HIV-1 and SIVcpz.
A recent study provides for the first time a clear picture of the origin of HIV-1 and the seeds of the AIDS pandemic. New strains of SIVcpz have been identified in wild chimpanzees from Cameroon. These new strains are more closely related to human HIV-1 than to any Simian viruses.
There are three HIV-1 lineages: M (Major), O (Outlier) and N (New). The new SIVcpz isolate MB66 turned out to be more closely related to HIV-1 group M than to any Simian virus (see a similarity search for SIVcpz MB66 gag-pol protein). Moreover, another wild virus, SIVcpz isolate EK505, is very closely related to HIV-1 group N. This suggests that at least two independent SIVcpz transfers from chimpanzee to man occurred in this region. HIV-1 group M presumably crossed species early in the 20th century. HIV-1 group N may have infected humans more recently.
The authors of the study also postulate that "given the extensive genetic diversity and phylogeographical clustering of SIVcpz now recognised and the vast areas of west central Africa not yet sampled, it is quite possible that still other SIVcpz lineages exist that could pose risks for human infection and prove problematic for HIV diagnostics and vaccines."
Cross-references to KEGG
The KEGG (Kyoto Encyclopedia of Genes and Genomes) database is part of the research projects of the Kanehisa Laboratories in the Bioinformatics Center of Kyoto University and the Human Genome Center of the University of Tokyo. The aim of this bioinformatics resource is to provide as far as possible a complete computer representation of the cell, the organism, and the biosphere, which will enable computational prediction of higher-level complexity of cellular processes and organism behaviors from genomic and molecular information.
The format of the explicit links in the flat file is:
|Resource identifier||KEGG's organism code for the genome and gene number, separated by a colon.|