Thursday, March 03, 2011

New Method Allows Human Embryonic Stem Cells to Avoid Immune System Rejection

Source: Stanford University Medical Center
Date: March 3, 2011

Summary:

A short-term treatment with three immune-dampening drugs allowed human embryonic stem cells to survive and thrive in mice, according to researchers at the Stanford University School of Medicine. Without such treatment, the animals' immune systems quickly hunt down and destroy the transplanted cells. The finding is important because it may allow humans to accept transplanted stem cells intended to treat disease or injury without requiring the ongoing use of powerful immunosuppressant medications.

Just as it does with transplanted organs, the human body recognizes foreign cells and rejects them. Embryonic stem cells, or ES cells, and the tissues they become are by definition immunologically different from any potential recipient. Physicians also have to overcome the fact that unspecialized ES cells can form tumors when transplanted into the body. The study is published in the March issue of Cell Stem Cell.

This paper, in tandem with a previous study by Wu published in February in the Journal of Clinical Investigation, helps to recast a scientific debate over the relative benefits of embryonic stem cells as compared with iPS cells, or induced pluripotent stem cells, which can be created from a person's own skin or other cells.