Chinese scientists reported that they changed the genes of the human embryo in an attempt to make it immune to HIV. This is the second known human fetal editing case, Nature News reports.
Chinese sources told reporters about the preparation of several articles on the results of the experiments. One of them was written by Yong Fan from Guangzhou Medical University.
Yong Fan and his colleagues collected 213 fertilized eggs in 2014, which were unusable for IVF (due to an extra set of chromosomes). Using the CRISPR-Cas9 technique, a mutation has been introduced into some embryos that changes the CCR5 gene. People who get this variant naturally do not become infected with HIV, as the CCR5 protein prevents the virus from entering cytotoxic T cells.
Four of the 26 embryos were successfully transformed. In others, “pure” versions of the gene remained or other modifications appeared (different from the required one - CCR5Δ32).
A number of scientists note that the Chinese study points to an unacceptable amount of technical difficulties in pinpoint editing of the human genome. They believe that first CRISPR techniques need to be perfected in monkeys, and only then move on to human embryos.
In February 2016, the UK Human Fertilization and Embryology Authority allowed British researchers led by Kathy Niakan of the Francis Crick Institute to conduct experiments on editing the genomes of human embryos. The ultimate goal of the project is to solve the problem of miscarriages. Scientists want to identify the genes that are most active in the first days of the fetus's life, when the embryo forms cells - the basis of the future placenta. Genes will be turned on and off using the Crispr-Cas9 tool.
In April 2015, Chinese scientists modified the genome of human embryos for the first time. As a result, 71 embryos survived, 54 were genetically tested, but in only 28 the CRISPR genome editor did his job correctly, and only four saved the corrected version of the gene. An article about this was refused to take in Nature and Science (the leading scientific journals of the world) due to ethical problems associated with editing the genome of human embryos.