The US researchers have found that human embryonic stem cell trigger an immune response in the mice. They also found that the the immune response in mice could be mitigated by the use of common antirejection medications. Thus, the study came as a sharp contrast to the previous studies. It suggests that the immune system is not blind to the presence of foreign embryonic stem cells.

Based on various studies, researchers have claimed that the embryonic stem cell cells may receive a kind of free pass from the normally vigilant immune system in order to allow the growth of a fetus that contains both maternal and paternal genetic material.

In the course of study, the researchers have found although the cells died within about seven to 10 days in mice with functioning immune systems, they survived and proliferated in the immunocompromised mice. Repeated injections of cells into the immune-normal mice led to more rapid cell death, indicating that the immune system was becoming more efficient at recognizing and rejecting the cells. The scientists believe it may be a protein that begins to appear on the surface of the cells as they differentiate into more-specialized tissues. Once the immune system has been primed to recognize the foreign molecules, it responds even more quickly to repeated invasion. continue to investigate whether different combinations can more effectively mitigate the immune response in mice.

Source: Market watch