03 Aug 2009
Scientists who found a new human immunodeficiency virus (HIV) in a Cameroonian woman living in Paris, have discovered it is an unusual variant of HIV-1 that could have come from gorillas.
The research that led to the findings was headed by Dr Jean-Christophe Plantier of the University of Rouen in France and is published in the 2 August online issue of Nature Medicine. Drs David Robertson and Jonathan Dickerson from the Faculty of Life Sciences at The University of Manchester, UK, were also involved in the study.
There are three established lineages of HIV-1, known as M, N, and O, which came from chimpanzees, but this new variant appears to be the prototype of a new lineage derived from gorillas and shows no evidence of recombination with the other known lineages, wrote the researchers.
They propose that the new lineage be called HIV-1 group P.
There are 33 million people worldwide living with AIDS which is caused by the HIV-1 virus group M (groups N and O are mainly confined to Cameroon).
HIV is a product of cross-species transmission of Simian Immunodeficiency Virus (SIV) found in chimpanzees, thought to have crossed to humans from eating infected bush meat.
While first recognized in 1980, HIV is thought to have started some 80 years earlier in and around the African country that is now called the Democratic Republic of Congo.
The 62-year old Cameroonian woman at the centre of the study moved to Paris in 2004 and began to have symptoms shortly afterwards. Her blood sample showed discrepancies in her viral load, and further tests revealed she was infected with a new strain of HIV that more closely resembled SIV from gorillas than HIV from humans.
However, before moving to Paris the woman had lived in a semi-urban part of the central west African Republic of Cameroon; she had not come into contact with bush meat or gorillas.
Because of this information and the fact further tests showed that the virus was able to replicate in human cells, the scientists suggest the strain may well appear elsewhere.
Robertson told the media that:
"The discovery of this novel HIV-1 lineage highlights the continuing need to monitor closely for the emergence of new HIV variants."
"This demonstrates that HIV evolution is an ongoing process. The virus can jump from species to species, from primate to primate, and that includes us; pathogens have been with us for millions of years and routinely switch host species," he added.
In the same way as the current swine flu pandemic is showing us, this is another example of how viruses can now move very quickly around the world because nowadays large numbers of humans travel long distances in a short space of time.
Plantier's team in France are part of a network of laboratories that has been monitoring HIV genetic diversity, while the The Manchester Life Sciences team helped with the computer-based evolutionary analysis.
"A new human immunodeficiency virus derived from gorillas."
Jean-Christophe Plantier, Marie Leoz, Jonathan E Dickerson, Fabienne De Oliveira, François Cordonnier, Véronique Lemée, Florence Damond, David L Robertson & François Simon.
Nature Medicine, Published online: 02 August 2009.