A team of scientists at the Dana-Farber/Boston Children's Cancer and Blood Disorders Center have manufactured red blood cells in a laboratory by combining the latest methods in genome editing with research on stem cells.
The findings of the study, featured in the journal Cell Stem Cell, suggest that the breakthrough procedure could provide a cost-effective way to produce red blood cells, which would benefit patients who cannot use blood available in blood banks.
While an earlier study has shown the possibility of using different methods to produce red blood cells using stem cells, the typical cost of around $8,000 to $15,000 for each blood unit makes these processes too expensive.
The Dana-Farber/Boston Children's study is first of its kind to combine stem cell research with advanced tools for gene editing and data collected from genome-wide association studies (GWAS).
Dr. Vijay Sankaran, a pediatric hematologist at the center, led a team of researchers in identifying a specific gene known as SH2B3 that contains naturally occurring variations of its sequence. Analysis of data from the GWAS has shown that the gene's sequence is capable of reducing its activity, leading to an increase production of red blood cells.
"There's a variation in SH2B3 found in about 40 percent of people that leads to modestly higher red blood cell counts," Sankaran explained. "But if you look at people with really high red blood cell levels, they often have rare SH2B3 mutations."
"That said to us that here is a target where you can partially or completely eliminate its function as a way of increasing red blood cells robustly," he added.
Sankaran added that many patients identified with blood disorders or rare blood types require specific blood kinds and cannot accept most blood donated to blood banks as well. There are also patients who depend on red blood cells to receive therapies.
In the recent study, the researchers wanted to find out whether the SH2B3 gene could be used to genetically increase the production of red blood cells in laboratories. They made use of a process called RNA interference (RNAi), which silences the expression from genes, in order to turn down the SH2B3 gene in stem cells.
The procedure targeted hematopoietic stem and progenitor cells (HSPCs) taken from adult humans and HSPCs from the blood found in umbilical cords.
The researchers discovered that by using RNA interference to shut off the SH2B3 gene, it allowed them to skew the cell production profile of the HSPCs to help improve production of red blood cells.
Stem cells treated with RNA interference led to three-to-five times (adult blood) and five-to-seven times (umbilical cord blood) more red blood cells compared to stem cells used as controls by the research team.
Through the use of multiple tests, Sankaran and his colleagues discovered that the RNAi-produced red blood cells were indistinguishable from those used as controls.
Sankaran pointed out that stem cells engineered to keep the SH2B3 gene turned off could be utilized as cellular starters capable of producing red blood cells for use in different treatments. These edited stem cells, however, would not be used in any direct treatment themselves.
The researchers hope that additional research in combining clustered regularly interspaced short palindromic repeats (CRISPR) and human embryonic stem cells (hESCs) could lead to increased yields in laboratory-based red blood cell production but at lower costs to allow manufacture on a commercial scale.
Photo: Andrew Mason | Flickr