Is AIDS likely to "self-heal"? Nature today reveals a rare defense against HIV infection without drugs.

At the beginning of human understanding of AIDS, the disease was a terminal disease that could not be saved.
more than 30 years, with the development of biomedical science, HIV antiviral treatment has made great achievements, AIDS into a controlled chronic disease.
for hiv-infected people, long-term effective antiretroviral therapy (ART) can control virus replication, so that the body's viral load reduced to an estrance level, the real infection rate to 0.
, a small number of people with HIV have been clinically found to be able to spontaneously control virus replication in some unknown way without receiving ART drugs.
known as "elite controllers", accounting for less than 0.5 percent of people living with HIV-1.
do these HIV-infected people gain unique defenses? From elite controllers, researchers hope to find better treatments for 99.5 percent of people living with HIV.
, Professor Yu and colleagues used genome sequencing to find clues in latent viruses.
long-term latent is the cunning of HIV, but also the current ART therapy is difficult to cure AIDS is the main obstacle.
specifically, HIV inserts its genetic information into the human genome into some cells of an infected person and becomes a so-called "pre-virus."
these pre-viruses do not produce their own viral proteins and are not recognized by the immune system.
"silently" waiting for the right time to "activate" and then copying them in large quantities again.
host cells that are latently infected have become a repository of viruses, proliferating through cloning and long-term presence in the body.
in these elite controllers, scientists have also found a reservoir of latent ex-viruses and replicable viruses.
to find out what characteristics of their latent virus repositories differ from those of the average HIV-infected person, the team analyzed 64 elite controllers and 41 infected people who received ART treatment over a long period of time.
comparing pre-viral sequences in cells, the researchers found that the number of pre-viruses in elite controller cells was significantly lower than in ART therapists.
, however, a large proportion of pre-virus sequences in elite controllers are genetically complete, meaning they have the potential to produce infectious virus particles.
using chromosomal integration bit analysis, the researchers further observed that there were significant differences in the location of the virus.
in the cells of elite controllers, complete pre-viral sequences are integrated into the non-protein coding region of human DNA or the KRAB-ZNF gene on chromosome 19.
these areas are made up of tightly packaged DNA, called isochromatin, which is often not conducive to HIV-1 integration.
, integration sites tend to be farther away from the host genome transcription starting point.
these characteristics mean that transcription of the virus is suppressed and in a deep latent (sleep) state.
, the researchers said, from these data, "the unique structural characteristics of pre-viruses are related to the natural control of HIV; the quality, not quantity, of latent virus reservoirs may be an important differentiating feature of functional cures for HIV infection."
, one example of elite controllers analyzed by researchers was not controlled with ART during follow-up for more than 23 years.
the researchers examined more than 1.5 billion of their exocytes, although 19 defective primary viruses were found, no complete sequence of pre-viruses was detected.
researchers point out that there have been no cases in which complete pre-viral sequences have been found in the genome after such a large number of cell analyses, and that there is only one case, the "Berlin patient" that emerged 12 years ago.
the patient received a CCR5-322 pure and hematopoietic stem cell transplant, HIV infection into continuous remission, is believed to be the first to be cured of AIDS patients.
this time, the HIV removal effect appears to have been achieved "on its own" with the elite controller. "While the logic of scientific discovery makes it impossible to confirm that this elite controller has achieved a clean-up cure for HIV infection through a natural immuno-mediated mechanism, it should be noted that we have analyzed a large number of cells using a range of complementary, highly sensitive testing techniques and have not been able to verify this hypothesis," the
researchers cautioned in their paper.
" is an extremely rare case that gives us a new possibility for humans to fight HIV infection.
.