Paris (AFP) - French scientists said Tuesday they had found the genetic mechanism by which two HIV-infected men may have suffered a "cure" spontaneous, and said he offered a new strategy to combat AIDS.
Both men were infected by the human immunodeficiency virus (HIV), one thirty years ago, but never developed symptoms of AIDS.
The virus that causes AIDS remained in their immune cells but was inactivated because its genetic code had been changed, the scientists said.
The change seemed to be related to increased activity of an enzyme called common APOBEC, they theorized.
The "apparent self-healing" raises an intriguing avenue for drug engineering, the team said in a statement.
"The work opens the way for a healing therapy using or stimulating this enzyme, and avenues for identifying individuals between newly infected that have a chance of spontaneous healing."
The study published in the journal Clinical Microbiology and Infection, was conducted by scientists at the French Institute of Health and Medical Research (Inserm).
HIV replicates by human immune cells invading CD4 that are reprogrammed to become virus factories.
A rare group of people - less than one percent of infected people - are naturally able to control viral replication and maintain the virus to undetectable levels.
They are known as "elite controllers", but the mechanism by which they keep the virus under control remains a mystery.
The French group observed such individuals, a man of 57 years diagnosed HIV positive in 1985, and a man of 23 years diagnosed in 2011, and the genomes of their viruses were sequenced.
Although they remain infected, standard tests can not detect the virus in their blood.
The team found that in both cases, the virus was unable to replicate in immune cells due to mutations of its genetic code.
The researchers suggest spontaneous evolution between humans and viruses, a process called "endogenization" believed to have neutralized other viruses in humans in the past.
A similar process has been witnessed in a population of the koalas that integrated an AIDS virus in their genes, neutralizing it, and passed the resistance to their offspring.
"We propose that cure HIV can occur through HIV endogenization in humans," the team wrote.
"These findings suggest that without therapeutic and prophylactic strategies, after several decades of HIV / host integration, and millions of deaths, it is likely that some individuals may have endogenizado and neutralized the virus and would transmit to their offspring, they add.
"We believe that the persistence of HIV DNA can lead to healing and protection from AIDS."
The approach adopted so far has been the opposite: to try and erase all traces of HIV from human cells and cellular reservoirs where they hide.
"We suggest that the persistence of the HIV DNA is not integrated as a barrier, but rather can be a prerequisite for HIV cure," said the study authors.
"We propose a new vision of the HIV cure through integration, inactivation and potential endogenization of a viral genome in the human genome."
- Not exclusive -
The staff said they did not believe that two patients were the only ones to develop this process or that the phenomenon is new.
And they called for a "massive" sequencing of the human DNA, particularly from African who had been exposed to HIV for the longest period possible endogenization, with the aim to find more evidence.
There is only a person who has literally been cured of HIV Timothy Ray Brown had bone marrow transplantation as a treatment for leukemia from a donor with HIV resistance. Editor's note: All attempts to repeat the feat resulted in death even after surgery
A baby who was given anti-AIDS medication immediately after birth and followed until eighteen months led scientists around the world to believe that the girl, oo Mississippi baby would have been healed, but the virus later also ended up destroying that hope.
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Translated from the original in EnglishScientists see mechanism for spontaneous HIV 'cure'by Claudio Souza.
Reviewed by Mara Macedo
Created by: Brigitte Castelnau