Swiss researchers have created mice with human immune systems, making it possible to study diseases that attack humans without using people as subjects, a new report says.Dr. Markus G. Manz, of the Institute for Research in Biomedicine in Bellinzona, and his colleagues took blood stem cells from human umbilical cords and transplanted them into infant mice that didn’t have their own immune systems.While earlier attempts failed to reconstruct the entire human immune system, this time the transplanted cells created many types of human immune system cells. These include cells called T-lymphocytes, B-lymphocytes and dendritic cells.Moreover, Manz’s group found these human immune cells worked along with the mouse’s own cells to make lymph system organ structures -- a major component of the body’s immune system -- and to produce regular immune responses.The scientists report how they created these animals in the April 2 issue of Science.
