动物造模,基因编辑技术 z-bio 2021-07-20 902

　　Scientists edit the pig genome to inactivate a family of retroviruses. These results have important implications for human transplantation medicine. The lack of human organs and tissues for transplantation is one of the most important unmet medical needs. One promising prospect is the use of animal organs in humans, and pig organs are particularly suitable for this type of transplant.

　　However, the porcine genome contains porcine endogenous retrovirus (PERV). When cells containing viruses are co-cultured with other cells, these viruses can infect other cells. Gene editing technology has been proven to remove viral genes from pig genomes and used to prepare pig-to-human organ transplants, but so far, these efforts have been successful in cell lines (living). animal).

　　Here, George Church, DongNiu and his colleagues have proven this feat in live animals. The researchers first confirmed that PERV in pig cells can infect pig cells when co-cultured with human cells. Contacting PERV-infected human cells with uninfected human cells can also cause the virus to spread. This highlights the need to inactivate pig PERV if one day it is necessary to transplant pig organs into humans.

　　Next, the researchers mapped and characterized the PERV present in the genome of porcine fibroblasts, and found a total of 25 PERVs. They used the gene editing tool CRISPR to inactivate all 25 genomic loci. Although there are highly modified cells in the cell population, when the PERV editing efficiency exceeds 90°, these cloned cells cannot proliferate.

　　However, by further mixing elements related to DNA repair, the research team was able to inactivate PERV up to 100 living cells to proliferate. When they implanted the embryos into the sows, they found that the piglets produced did not show signs of PERV, and some piglets were still alive before 4 months of age.