CRISPR gene editing could let us hack the immune system to give lasting protection against HIV and other infections. Experiments in mice suggest that the technique could be used to give people immunity from a range of viruses for which there are no effective vaccines.
Justin Taylor at the Fred Hutchinson Cancer Research Center in Seattle, Washington, and his colleagues used the CRISPR technique on white blood cells called B-cells. These are part of our natural immune system and secrete antibody proteins that attack particular bacteria and viruses. While effective against many pathogens, these protective antibodies don鈥檛 work as well as needed against some viruses. This is one of the reasons researchers have struggled to develop vaccines 鈥� which trigger the body to develop antibodies 鈥� against some infections like HIV.
To get around this problem, better versions of some antibodies can be created artificially and then given to those who need them. For example, the lab-made antibody palivizumab is very effective against the respiratory syncytial virus (RSV), which infects the respiratory tract and can be lethal in infants and older people. Injections of palivizumab are used to treat RSV infections in these high-risk groups, but the antibody breaks down quickly in the body, meaning these expensive injections have to be repeated throughout treatment.
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Taylor and his colleagues hope that editing the DNA of B-cells to produce better antibodies could lead to a steady supply of new antibodies without the need for repeat injections. If it works, this could provide immunity against certain pathogens.
The researchers tested the idea by giving B-cells taken from donor mice the genetic instructions to make palivizumab for themselves. When they gave 15 other mice an injection of these cells, they found that they were protected from the virus for as long as 82 days.
The team was also able to edit human B-cells to produce antibodies to RSV, HIV, flu and the Epstein-Barr virus that causes glandular fever or mononucleosis. None of these antibodies haven been tested in people yet.
Gene-editing B-cells is a new CRISPR frontier, says Richard James at the Seattle Children鈥檚 Research Institute, who was part of the first group to successfully use the technique on these immune cells in 2017. Teams around the world are now vying to be the first to test edited B-cells in human trials 鈥� which can only be done after tests confirm they are safe.
鈥淲e have some hurdles to cross before we try it,鈥� says James, who predicts it could take聽three to five years to get to that stage. 鈥淏ut this is a good step forward and a neat way to use the technology.鈥�
Other ways of using gene editing to boost the immune system are further along. A small trial in 2014 found it was safe to give people T-cells 鈥� another part of the immune system 鈥� that had been gene-edited in an effort to protect against HIV.
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