Abstract: This invention provides a system for rapid determination of pharmacologic effects on target tissue types in cell populations cultured in vitro. The cells contain a promoter-reporter construct that reflects a toxicologic or metabolic change caused by the agent being screened. The promoter is taken from a gene known to be up- or down-regulated according to the metabolic state of the cell, and linked to a reporter gene that provides an external signal for monitoring promoter activity. The promoter-reporter cells may be produced by placing these genetic alterations into a line of human embryonic stem cells, bulking up the cells to any extent desired, and then differentiating the cells into the desired tissue type. This disclosure explains some of the powerful features of the promoter-reporter cells of this invention, and shows various ways the skilled reader can use the invention for pharmaceutical development and testing, or to monitor graft survival.

Abstract: This disclosure provides a system for creating cloned cells and embryos that are genetically modified. Cells are treated to increase expression of telomerase and potentially extend replicative capacity. One or more genetic modifications is made to inactivate a gene or confer desirable features, growing and selecting the cells as needed. The modified nucleus can then be transferred to a suitable recipient cell, which can then be used to grow an embryo with the conferred attributes. This technology makes it possible to create embryos, animals and embryonic cell lines with multiple genetic modifications, including homozygously inactivated genes and gene substitutions.

Abstract: This disclosure provides a system for generating animal tissue with carbohydrate antigens that are compatible for transplantation into human patients. The tissue is inactivated homozygously for expression of ?(1,3)galactosyltransferase, and comprises a transgene for ?(1,2)fucosyltransferase. As a result, cell-surface N-acetyl lactosamine is not converted to the Gal?(1,3)Gal xenoantigen. Instead, it is converted to Fuc?(1,2)Gal, which is H substance, a self-antigen in humans. The tissue may also contain A or B-transferase, which will cause H substance to be converted into other ABO blood group antigens for compatibility with patients of the same blood type. This invention improves transplant compatibility of the xenograft tissue by lessening the risk of reactions resulting from xenoantigen and unconverted N-acetyl lactosamine acceptor determinants.

Abstract: This disclosure provides a system for creating cloned cells and embryos that are genetically modified. Cells are treated to increase expression of telomerase and potentially extend replicative capacity. One or more genetic modifications is made to inactivate a gene or confer desirable features, growing and selecting the cells as needed. The modified nucleus can then be transferred to a suitable recipient cell, which can then be used to grow an embryo with the conferred attributes. This technology makes it possible to create embryos, animals and embryonic cell lines with multiple genetic modifications, including homozygously inactivated genes and gene substitutions.

Abstract: This disclosure provides a system for generating animal tissue with carbohydrate antigens that are compatible for transplantation into human patients. The tissue is inactivated homozygously for expression of &agr;(1,3)galactosyltransferase, and comprises a transgene for &agr;(1,2)fucosyltransferase. As a result, cell-surface N-acetyl lactosamine is not converted to the Gal&agr;(1,3)Gal xenoantigen. Instead, it is converted to Fuc&agr;(1,2)Gal, which is H substance, a self-antigen in humans. The tissue may also contain A or B-transferase, which will cause H substance to be converted into other ABO blood group antigens for compatibility with patients of the same blood type. This invention improves transplant compatibility of the xenograft tissue by lessening the risk of reactions resulting from xenoantigen and unconverted N-acetyl lactosamine acceptor determinants.