“Therapeutic” Cloning Still Faces Immune Rejection
Proponents of therapeutic cloning say they want to use embryos cloned from a patient’s own cells to develop genetically personalized therapies for each individual patient. In theory, because the stem cells derived from the cloned embryo would have the same DNA as the patient, the problem of immune rejection would be solved.
But in reality, a recent study shows that cloned embryonic stem cells are still subject to rejection (W.M. Rideout et al., “Correction of a genetic defect by nuclear transplantation and combined cell and gene therapy,” Cell Immediate Early Publication, DOI:10.1016/S0092867402006815, March 8, 2002). And given the widely acknowledged inefficiencies and expense of cloning, many scientists — including proponents of embryonic stem cell research – doubt it can ever be a part of routine medical therapy. James Thomson, considered the father of human embryonic stem cell research, notes: “it is difficult to envision this [human embryo cloning to produce stem cells] becoming a routine clinical procedure” (J.S. Odorico, D.S Kaufman, J.A.Thomson,”Multilineage differentiation from human embryonic stem cell lines,” Stem Cells 19, 193-204; 2001
Either we need stem cells with our own genetic makeup or we do not. If we do, and cloning is simply too inefficient and expensive, we should stop wasting time and resources on it when adult stems cells are already available to meet our DNA needs and already providing real therapies.