HLG-G made by mesenchymal stem cells

Besancon, France -

The ability of mesenchymal stem cells to inhibit inflammatory immune responses has been established in in vitro models, as well as in clinical trials of inflammatory conditions, such as the trials of Osiris for treatment of GVHD and Crohn's disease.

In a recent paper (Selmani Z et al. HLA-G5 secretion by Human Mesenchymal Stem Cells Is Required to Suppress T-lymphocyte and NK Function and to Induce CD4+CD25highFOXP3+ Regulatory T Cells) a novel mechanism by which mesenchymal stem cells inhibit the immune response was described.

The investigators identified that mesenchymal stem cells secrete a soluble isoform of HLA-G called HLA-G5. By addition of blocking antibodies to HLA-G5 the investigators were able to abrogate MSC induction of:

1. Inhibition of allogeneic T cell proliferation
2 Expansion of CD4CD25FOXP3 regulatory T cells

Additionally, they demonstrated that the soluble HLA-G5 was capable of inhibiting natural killer cell production of interferon gamma, as well as cytotoxicity.

This study supports the possibility of using mesenchymal stem cells in the treatment of multiple sclerosis, as presented in the video below.