Leading molecular biologists in China analyzed the methods of work of He Jiangkui, the scandalous creator of the first genetically modified children, and found a lot of serious errors in his experiments. Their scientific criticism was published in the journal PLoS Biology.
At the end of November last year, the Chinese molecular biologist He Jiankui revealed that he was able to carry out the first "operation" to edit the DNA of a human embryo and obtain the first "transgenic" children, invulnerable to the action of the immunodeficiency virus.
These revelations caused a storm of protests among politicians, scientists and philosophers. In addition, Jiankui’s activities, as reported by the Chinese press at the time, attracted the interest of Chinese law enforcement agencies and the ethics commission of the Southern University of Science and Technology in Shenzhen, where he worked.
Interest in his research was fueled after the geneticist mysteriously disappeared in early December, and began to respond to inquiries only in early January, when rumors appeared that he could be sentenced to the death penalty.
After that, several interesting details were revealed that significantly expanded the circle of Jiankui's accomplices and made the public and scientists think again about how permissible such experiments are and how they should be regulated.
Haoyi Wang from the Institute of Zoology of the CAS and Hui Yang from the Institute of Neurophysology of the CAS in Beijing criticized the disgraced experimenter today. They are considered among the leading experts in the modification of DNA in primates and humans in the PRC and around the world in general.
The main problem with these experiments, the researchers emphasize, was that such DNA modifications were simply not needed to protect children from HIV infection. This could have been avoided by taking conventional antiretroviral drugs for several weeks before conception.
In addition, the mutant version of the CCR5 gene that Jiankui inserted into fetal genomes is found only among Europeans and is absent from China. According to Yang and Wang, its appearance in the gene pool of the PRC can lead to a lot of unpredictable consequences.
Promotional video:
Scientists also have big questions about the results of experiments on mice and monkeys. According to geneticists, He was very careless about checking whether the editing of the genome led to the appearance of new "typos" in the DNA of animals. He limited himself to observing changes in the behavior of rodents and the structure of some tissues, and did not begin to track shifts in the work of cells and genes at the molecular level.
In addition, the scandalous scientist carried out the very modification of DNA, using intracellular mechanisms that allow you to cut out a particular gene, but not guaranteed and safe to replace it with a new version of this genome segment.
This led Wang and Yang to suspect that Jiankui wasn't even trying to replace the "Chinese" variation of CCR5 with a rare European version of that gene, but simply wanted to delete the gene. This approach also makes it possible to achieve resistance to the action of most HIV strains, but it is much more dangerous and unpredictable for the modified organism.
The biggest problem, in turn, was that He stated that he could not avoid mosaicism, the emergence of two sets of cells with different genomes in the embryo. In other words, editing the genome led to the replacement of CCR5 in far from all cells of the embryo, which indicates the low efficiency and accuracy of editing.
All traces of mosaicism magically disappeared, according to Jiankuyu, after the birth of one of the babies, in whose umbilical cord blood the scandalous scientist found traces of only the "correct" version of CCR5. This, according to Yang and Wang, is, in principle, not possible, since fragments of maternal DNA with a normal variant of this gene should have been present in it.
Considerations like these, the researchers conclude, make them strongly doubt that these experiments protected children from HIV. In addition, it is not yet clear if Jiankui is hiding any important details that could explain the discrepancies and shed light on what he actually achieved.