New clinical applications in regenerative medicine are motivating an intense interest in easily accessible sources for producing human stem cells. The 2007 breakthrough showing that induced pluripotent stem cells (iPSC) could be generated directly from adult cells has been a boon to the industry. Since that time, there has been a steady refinement of the cell culture techniques that guide the cell reprogramming process.
Peripheral blood is one of the most easily available sources of adult cells. The existence of blood banks and cell collection centers with large donor networks provides for access to a wide variety of diverse, well-characterized donors. In addition to accessibility, PBMCs offer other advantages over various cell types used for generating iPSC:
- Obtaining PBMCs is minimally invasive and nearly painless for the donor.
- Unlike fibroblasts, the cells are naturally replenished from stem cells in the bone marrow.
- Freshly isolated PBMC need only be cultured for a few days before reprogramming protocols can begin, in contrast to primary cell lines, which require 2-3 weeks to become established in culture.
Advances in human iPSC research are improving the efficiency of the reprogramming process that guides somatic cells toward a pluripotent state. A recent publication in the journal Regenerative Medicine  reported using HemaCare sourced PBMC cells to generate iPSCs with the aid of a newly developed reprogramming kit. Their research team is focused on developing pluripotent stem cell protocols specifically aimed at clinical and translational research. As part of this process, the authors transitioned to the use of xeno-free media that does not contain any animal components. Each culture media candidate was evaluated for reprogramming efficiency. The team’s end goal is to provide protocol reagents that are more closely aligned with clinical regulatory guidelines from the start. The team also streamlined the reprogramming process by identifying and eliminating several work-flow gaps.
Other research teams are delving into alternative methods of improving iPSC production efficiency. One group  developed an automated serial plating system that took advantage of the adherent properties of PBMCs. The authors were able to use this system to generate multiple healthy iPSC colonies from a limited quantity of PBMC cells. They went on to functionally characterize the iPSC cells, and demonstrate that they were capable of differentiation into each of the three germ layers found in early embryos.
Pluripotent stem cells are crucially important to disease modeling, drug screening, and regenerative therapies. PBMCs are an ideal starting material source for iPSC research due to their relative ease of collection, and the opportunities for access to either healthy or disease-state donors. Due to the fact that they are continually replenished, PBMCs are less prone to DNA damage that can plague fibroblasts exposed to sun and chemicals. PBMCs from whole blood can be reprogrammed almost immediately after collection, streamlining iPSC production workflows. As advances continue to be made, PBMC derived iPSCs are on target to fuel a new generation of clinical applications.
- MacArthur C.C., et al. Generation and comprehensive characterization of induced pluripotent stem cells for translational research. Regenerative Medicine; 14(6). May 2019.
- Kim Y., et al. The Generation of Human Induced Pluripotent Stem Cells from Blood Cells: An Efficient Protocol Using Serial Plating of Reprogrammed Cells by Centrifugation. Stem Cells International. 1-9. 2016.