9 May 2005
Human embryonic stem (ES) cell lines are currently the focus of intensive research with a view to developing therapeutic interventions against a range of diseases, because these cells are pluripotent, having the potential to differentiate into any type of specialised cell. The hope is that they could therefore be stimulated to develop into the appropriate sort of cell to replace damaged or dysfunctional cells. Besides concerns over the ethical issues associated with the use of cells derived from human embryos, the safety of using such cells for transplantation is also an important consideration. A new paper in Nature Medicine reports that human ES cell lines are effectively contaminated with animal cell surface molecules and would therefore induce an immune rejection reaction if transplanted into human recipients (see also BBC news report).
ES cells are initially cultured on mouse embryonic fibroblast