Propagation of human hepatocytes in non-human animals

Patent Number: 6995299

This patent teaches ways of growing human hepatocytes in xenogenic hosts. This patent would be useful for using animals as "bioincubators" in order to grow organs or cells for human use. Specifically the patent has two independent claims. The first covers a model of hepatitis C in which a mammal is injected with human hepatocytes when it is in the fetal stage, thus becoming tolerized, and subsequently transplanting human hepatocytes and infecting the animal. The second is a method of preparing a non-human fetal mammal to recieve a human hepatocyte graft. This second claim covers the method of fetal tolerization, as well as administration of a hepatocyte toxin. The author published on this model, for example (Ouyang EC et al. Transplantation of human hepatocytes into tolerized genetically immunocompetent rats. World J Gastroenterol. 2001 Jun;7(3):324-30). One wonders if human hepatocytes, or even embryonic stem cells, can be grown in an animal, the animal injured to allow proliferation of all cells, then sacrificing the animal and extracting the human differentiated cell for human use. This approach would most likely need to be performed with cellular tranplants such as islets, but I wonder about hepatocytes...

View this patent on the USPTO website.