Banking on stem cells
Cellular Dynamics and ISCO create HLA haplotype-matched stem cell banks
While stem cell developers wrestle with fine-tuning cell types, improving protocols and calling for better regulatory guidelines, few in the field are addressing one of the looming problems likely to hit once more products reach the market - stem cell rejection. Taking a leaf from the organ transplant field's notebook, two companies are creating genetically matched donor cell banks to reduce the risk of rejection, but it's not clear whether the strategy will eliminate the need for immunosuppressants.
The companies, Cellular Dynamics International Inc. and International Stem Cell Corp. (ISCO), are starting from the same premise: that the key lies in ensuring histocompatibility by matching HLA haplotypes.
But while Cellular Dynamics is looking for rare HLA haplotype "super donors" to fill its bank, ISCO is using its parthenogenesis technology to create HLA haplotype matched cell lines from virtually any healthy egg donor (See <div>Figure: Pluripotent choice</div>).
HLA is used by immune cells to distinguish self from non-self antigens. When recipient immune cells recognize cells from HLA mismatched donors as foreign, the donor cells are rejected.
There are three principal paradigms for creating stem cells for transplants: autologous cells that come from the patient and are fully