He Jiankui of the Southern University of Science and Technology in Shenzhen (China) announced to the world that it had worked on the conception and birth of the first genetically modified children:it would be a pair of Chinese twins, who came to light in early November.
The news was spread from Mit Technology Review , which was followed by the exclusive interview with the Associated Press agency, in which He he explained how thanks to the genomic editing technique Crispr has in practice tried - and succeeded, according to him - to immunize future human beings from HIV infection, the AIDS virus, by deactivating a gene.
He has taken responsibility for what many do not hesitate to define as a human experimentation with unpredictable implications, both from a biological and an ethical point of view.
Experimentation
With the support of the US professor of physics and bioengineering Michael Deem , He and her research team have launched a trial to create what is officially called an HIV vaccine at Home Women's and Children's Hospital in Shenzhen . He reports that seven Chinese couples who had requested access to in vitro fertilization (IVF) services were involved in the study (of which there is no publication or review by independent experts so far). In all couples, the man had contracted AIDS, while the woman was healthy. By participating in the trial, couples could undergo IVF for free.
Obtained permission from the facility's ethics committee and informed consent (although some doubts that future parents understood all the risks) of the participants, He and his colleagues began the experiment by creating a total of 16 genetically modified embryos with Crispr-cas9 to inactivate the Ccr5 gene . This gene encodes a membrane protein that is believed to be the HIV gateway to cells. The meaning is:no Ccr5, no infection - or at least greater protection of the unborn. A motivation rather than ethical according to the researchers, because AIDS in China and in the world constitutes a serious problem for public health, as well as for the well-being of the person. In fact, researchers often justify themselves, AIDS patients lose their jobs and are discriminated against.
After in vitro fertilization, embryos at an early stage of development were analyzed to ascertain that the genome had been modified. Of all the implants, one would have been successful and the pregnancy would have been completed this month. He reports that two girls were born, Lulu and Nana, one of whom carries both modified copies of the Ccr5 gene, while the other is heterozygous.
From a technical point of view, the security with which these results were disseminated is contested because the tests carried out would not actually be sufficient to be able to affirm that the modification was successful and above all that the use of Crispr-cas9 did not damage the rest of the genome.
Even if this were the case, then, one of the twins would in practice be a mosaic of cells, some with the genetic modification and others not, and this would not give the child any advantage because she would still be susceptible to HIV infection . So why choose to implant a modified embryo knowing a priori that it would not have the expected benefits and exposing the unborn child to still unknown risks for its safety? Some exponents of the international scientific community also point out that Ccr5 facilitates the entry of the AIDS virus into cells but from another perspective it confers resistance to other types of more common infections, less preventable and treatable than HIV such as influenza and West Nile viruses - diseases that still die for today.
“ He it was foolish to choose this gene for the mutation, because it could have compromised the lifespan of the two girls ", says he, the British scientist Robin Lovell-Badge , stem cell expert from the Francis Crick Institute , who was not involved in the new study.
The so-called delta-32 mutation seems to make people resistant to HIV when it is dependent on both copies of the CCR5 gene, one inherited from each parent; while a copy of the mutation provides slightly weaker protection. Researchers from the University of California at Berkeley searched for this common CCR5-delta-32 mutation in a database of more than 400,000 middle-aged and senior UK volunteers.