the genetically modified antibody track

THE ESSENTIAL

  • It is possible to modify the B lymphocytes so that they become largely neutralizing antibodies (or bNAbs).
  • BNAbs are able to fight several strains of HIV at the same time, which makes them very effective against this rapidly mutating virus.
  • The system is successful in mice. If it works as well in humans, it could pave the way for a vaccine.

If the fight against Covid-19 is progressing quickly, that against HIV is changing very little. Yet the human immunodeficiency virus (HIV) is still fatal, has been around for a long time and still does not have a vaccine. For this last point, maybe that could change. Scientists at Scripps Research (USA) have made a big leap forward in research on this subject thanks to genetically modified immune cells that could prevent HIV infection. The results of the study were published on November 17, 2020 in the journal Nature communications.

Antibodies capable of dealing with several HIV mutations at the same time

Until now, the difficulty with HIV has been in preventing infection. Because of its rapid development in the body, it is almost impossible for conventional antibodies to stop the spread of the virus. To do this, the body would need to be able to produce antibodies capable of defeating several strains of the virus at the same time.

It is precisely on this approach that the scientists of Scripps Research were based. By trying their experiment on mice, they succeeded in producing largely neutralizing antibodies also called bNAbs (for broadly neutralizing HIV-1 antibodies). BNAbs antibodies have the particularity of being able to attack several strains of HIV at the same time. The problem is that such antibodies are still hard to produce, only a few rare patients with HIV have them.

Modify lymphocytes to make them stronger

To successfully develop them on a large scale, the Scripps Research teams understood that it was possible to use the CRISPR-Cas9 genetic scissors to reprogram the genes of B lymphocytes so that they in turn naturally produce bNAbs antibodies. . Once the modification was made, the B lymphocytes reinjected into the mice were able to multiply, mature and become memory B lymphocytes and plasma cells, capable of protecting the organism for a long time. Thus, these altered genes can produce more effective antibodies against HIV.

This is the first time that modified B cells have been shown to create a lasting antibody response in a relevant animal modelsays James Voss, a researcher in the Department of Immunology and Microbiology at Scripps Research. In humans, the starting cells to create the vaccine could be obtained easily from a simple blood test, then developed in the laboratory before being reintroduced into the patient..”

James Voss and his team are now trying to improve the technology so that it becomes accessible to as many people as possible. According to the estimates of United Nations Program on HIV / AIDS (UNAIDS), 38 million people would be infected with HIV worldwide in 2019 and more than 12 million of them do not have access to treatment.


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