A functional immune system can be derived from embryonic stem cells, preliminary s...(ent while in the womb it was unclear if ...),Health

In this study, a team of scientists from Iowa, Taiwan, and Germany used HOXB4-containing ESCs to engraft the bone marrow and rescue mice that genetically lacked any immune system and had been irradiated to destroy their bone marrow. Only cells containing HOXB4 were able to engraft, rescue the mice, and produce blood cells long term. These engrafted cells were shown to be derived from the transplanted ESC-derived cells.

To determine if these transplants were able to rebuild the defunct immune system, the scientists injected the mice with LCMV, a common rodent virus, and watched for T-cell activity, a sign that the body was defending itself against the infection. Although the number of T cells generated by the new hematopoietic cells was low, they were able to respond effectively to the virus. In addition, the transplanted hematopoietic cells were also able to produce B cells and other defensive cells called antigen-presenting cells, which have a role in signaling T cells to action. They also tested the ability of the mice to respond to vaccination and demonstrated the induction of specific immune cells. Although the level of immune response was not what is seen in normal adult mice after exposure to the virus or vaccine, it was measurable and effective.

The study was also encouraging in that none of the 70 transplanted mice followed for more than 200 days developed any tumors another concern when using ESCs for tissue regeneration.

These results show, for the first time, that functional white blood cells, the key players in the bodys immune system, can be successfully derived from embryonic stem cells expressing HOXB4, said lead study author Nicholas Zavazava, MD, PhD, Professor of Internal Medicine and Director of Transplant Research at the University of Iowa Hospitals and Clinics in Iowa City and Staff Phy
'/>"/>