Many AIDS researchers suspected that the most common strain of HIV, HIV-1, has been lurking in the human population since the 1950s or even earlier. Now scientists have confirmed that is the case: HIV-1 fragments from a 1959 blood sample cases represent the earliest known HIV infection. The results, presented today at the 5th Conference on Retroviruses and Opportunistic Infections in Chicago, could provide a clue to how the virus could spread from primates to people, and could help vaccine designers learn to face the remarkable genetic diversity of modern strains of HIV.
a team led by David Ho, director of the Aaron Diamond Center for AIDS Research in New York, analyzed the plasma of a man who, in 1959, lived in what is now Kinshasa, Democratic Republic of Congo. The sample was collected as part of a larger study of the genetics of the immune system, and in 1986, he tested positive for HIV antibodies, indicating the possible presence of the virus.
Ho and his colleagues used a highly sensitive technology called polymerase chain reaction to detect and amplify small amounts of HIV genetic material in the sample. They got four small fragments - only 15% of the complete genome of HIV-1 - they then sequenced. When two experts in the history of the evolution of HIV virus compared to 1959 called ZR59, with modern strains of HIV, they found it to be very closely related to the common ancestor of the three strains found in Europe , North America and Africa. The team believes that this common ancestor must have been introduced into human animals sometimes in 1940 or 1950. The Ho Group describes its results in this week's issue of Nature .
The 1959 sample "provides a potential missing link" in the early origins of HIV, said Francine McCutchan, a molecular biologist at the Henry M. Jackson Foundation for the Advancement of Military Medicine in Rockville, Maryland . This information, McCutchan said, could help pharmaceutical companies develop a vaccine based on common features shared with the first HIV ancestors - highly conserved features and therefore probably crucial that may prove to be more universal targets to fight against the epidemic global vaccine based on a combination of a cocktail of modern HIV strains, the genetic codes differ from each other by 10% or more.
0 Komentar