Precursors of AIDS viruses tens of thousands of years old

Health research: precursors of AIDS viruses tens of thousands of years old. New questions for AIDS research.

(17.09.2010) The precursor of the AIDS virus HIV is older than expected. According to American scientists from the Tulane National Primate Research Center at Convington, the original form of the virus must be at least 32,000 years or older. The US scientists were able to identify SI virus strains, the prototype of the pathogen of the immune deficiency disease AIDS, in monkeys on the African island of Bioko. The island has already separated from the mainland about 10,000 to 12,000 years ago, so that the monkeys have since been isolated and, according to the researchers, should not have any SIE viruses.

The fact that more than 25 percent of the monkeys tested on the West African island of Bioko still carried the Simian Immunodeficiency Virus (SI) virus contradicts the previous position of all experts. On the basis of older molecular-biological analyzes, they had assumed that the pathogen could reach a maximum age of a few hundred years. However, with the help of intensive DNA testing and subsequent computer-calculated models, based on biological experience, the US researchers now come to the in the current issue of the „Science“ Science magazine published findings that the SI virus must be between 32,000 and 75,000 years old.

The scientists argue that the biologist Michael Worobey from the University of Arizona as well as the virologist Preston Marx from „Tulane National Primate Research Center“ in their estimation of age on the one hand logical genetic and on the other hand historical-reconstructing. Since the island of Bioko separated from the mainland more than 10,000 years ago, it believes that the SI virus was already common in certain species of monkeys. The SI viruses now found on Bioko have a different evolutionary history than the SI viruses on the mainland, so they clearly differ in their DNA. Preston Marx, head of the research group at the Tulane National Primate Research Center, explains that the viral strains of the original peninsula were separated from those on the mainland and then evolved independently. In addition, due to the relatively small molecular alteration of SI viruses over time, the experts come to the conclusion that the evolution of the pathogen progresses much slower than previously thought.

The SI virus has evidently been transported by monkeys in the organism for millennia, but unlike the HI virus it does not trigger AIDS in most infected animals today. However, according to the researchers, the slow molecular evolution of the virus probably took thousands of years to turn a deadly virus into a relatively benign pathogen. Just as long, it could take, according to the US researchers on the basis of natural molecular evolution until the virulence (ability of the pathogen to cause disease) of HIV goes back.

Based on the findings, the researchers now hope to be able to trace the development of the HI virus. Whereby the scientists ask themselves the question, how humans could live for thousands of years next to infected, AIDS-affected primates, without the immunodeficiency disease broke out with them.

Today, more than 33 million people worldwide are infected with HIV. The virus from the family of retroviruses triggers the immunodeficiency syndrome AIDS (acquired immunodeficiency syndrome) after a partially several-year incubation period, the consequences of which kill about 2 million people each year. There is no such thing as a successful treatment, even though many people in the modern industrialized nations have quite a lot to offer due to the relatively effective active ingredients for alleviating the symptoms „normal“ Can lead lives. The spread of the HIV virus has become a pandemic over the last 25 years, which UNAIDS estimates has cost approximately 25 million lives to date, with particular impact on the African continent. (Fp)

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Picture credits: Michael Ottersbach