Use of HLA-homozygous stem cells to avoid immunogenicity

An interesting paper was just published by a team lead by Jean Villard at the Geneva University Hospital regarding the idea of HLA-homozygous stem cell being used as a bank so that a limited number of lines could cover many individuals.

In the article entitled: Haplotype-Based Banking of Human Pluripotent Stem Cell for Transplantation: Potential and Limitations (Stem Cells and Development,  Volume 21, Number 13, 2012) Villard et al from carefully review available scientific literature, and provide multiple lines of evidence pointing to the generation of  HLA-homozygous pluripotent stem cell banks may be a way towards the sustainable development of regenerative medicine. The paper points out the advantageous effect of complete or partial HLA matching for the graft survival, explaining that such matching process could be greatly facilitated by the use of HLA-homozygous stem cell lines.  The authors write: “All these results indicate that the number of cell lines needed in a pluripotent stem cell bank, which would provide matches for a majority of the population, could be drastically reduced if it contained homozygous lines.” They conclude: “The establishment of multiple regional banks, accounting for the variability of HLA haplotypes in different human populations, should be strongly considered to advance medical and research purposes.”

International Stem Cell Corporation has been advocating such solution ever since its inception in 2005. Its unique technology allows for derivation of transplantation-compatible HLA-homozygous parthenogenetic stem cells.  One of our HLA-homozygous lines carries the most common haplotype in the Caucasian population, present in 4%.