Abstract: Genetically engineered or transduced hepatocytes which express genetic material of interest introduced or incorporated into them, as well as methods of producing, transplanting and using the genetically engineered hepatocytes are disclosed. The genetic material of interest can be incorporated through the use of a vector, such as a recombinant retrovirus, which contains the genetic material of interest, or by other means.

Abstract: Fibroblasts transduced with genetic material encoding a polypeptide or protein of interest and, optionally, a selectable marker, as well as methods for making and using the transduced fibroblasts. Such fibroblasts are useful in delivering the encoded polypeptide or protein, such as an enzyme, a hormone or a drug, to an individual who has had a graft or implant of the transduced cells.

Abstract: Packaging cell lines useful for the generation of helper-free recombinant retroviruses with amphotropic or ecotropic host ranges, methods of constructing such packaging cell lines and methods of using the recombinant retroviruses to introduce DNA of interest into eukaryotic cells, both in vitro and in vivo.

Abstract: Epithelial cells expressing foreign genetic material are described. The foreign genetic material can be DNA or RNA which does not occur in epithelial cells; DNA or RNA which occurs in epithelial cells but is not expressed in them at levels which are biologically significant; DNA or RNA which occurs in epithelial and has been modified so that it is expressed in epithelial cells; and any DNA or RNA which can be modified to be expressed in epithelial cells, alone or in any combination thereof. In addition, epithelial cells of the present invention can express genetic material encoding a selectable marker by which cells expressing the foreign genetic material can be expressed.

Abstract: Epithelial cells expressing foreign genetic material are described. The foreign genetic material can be DNA or RNA which does not occur in epithelial cells; DNA or RNA which occurs in epithelial cells but is not expressed in them at levels which are biologically significant; DNA or RNA which occurs in epithelial and has been modified so that it is expressed in epithelial cells; and any DNA or RNA which can be modified to be expressed in epithelial cells, alone or in any combination thereof. In addition, epithelial cells of the present invention can express genetic material encoding a selectable marker by which cells expressing the foreign genetic material can be expressed.