Severe combined immunodeficiency disease (SCID) is a group of rare genetic disorders that prevent the bone marrow from making important immune cells such as the natural killer (NK) cells and T cells. The lack of NK and T cells severely disrupts the immune system and renders the person defenseless even to the mildest of infections. Children born with SCID are often covered in a bubble bag, hence the name ‘bubble boy’, in order to maintain a sterile environment that protects them from pathogens.
Previously, gene therapy was considered a promising technique to treat SCID but when viruses were used to deliver correct genes to the bone marrow, often leukemia developed and so scientists had to resort to other forms of gene therapy that only benefitted those with mild SCID.
Now a research team from Salk Institute of Biological Studies has managed to generate NK cells from genetically edited stem cells of an SCID patient.
The process targets a very specific form of SCID known as X-linked severe combined immunodeficiency disease (X-SCID) by obtaining cells from the patient and then converting them to induced pluripotent stem cells (iPSCs). The iPSCs are then genetically modified at specific points using the gene editing technology known as TALEN, that involves the use of enzymes that can cut out individual nucleotides at specific points to correct the X-SCID causing faulty genes. These cells are then treated to produce NK cells. This is a significant breakthrough, as this process will ensure immune compatibility as well as an unlimited supply of NK cells (since stem cells can divide indefinitely).
Despite its promise, this process is still in its early stages and scientists still need to figure out how to generate T cells that are also scarce in SCID patients. The research team has been able to generate a precursor of a T cell but generating a mature T cell from the gene-edited iPSCs cells is yet to be done.
Article: Medical News Today
Research Paper: Cell Stem Cell
Article Summary Courtesy of Waleed Khan