Abstract: The subject invention is directed to a mixed cell composition to generate a therapeutic protein at a target site by providing a first population of mammalian cells transfected or transduced with a gene that is sought to be expressed, and a second population of mammalian cells that have not been transfected or transduced with the gene, wherein endogenously existing forms of the second population of mammalian cells are decreased at the target site, and wherein generation of the therapeutic protein by the first population of mammalian cells at the target site stimulates the second population cells to induce a therapeutic effect.

Abstract: The present application discloses a method of preventing degeneration of nerve, which includes: a) generating a recombinant viral or plasmid vector comprising a DNA sequence encoding a member of a transforming growth factor superfamily or neurotrophic factor proteins operatively linked to a promoter; b) transfecting in vitro a population of cultured cells with the recombinant vector, resulting in a population of the cultured cells; and c) transplanting the transfected cells to an area near an injured nerve, such that expression of the DNA sequence within the area near the injured nerve causes prevention of degeneration of the nerve.

Abstract: The subject invention is directed to a mixed cell composition to generate a therapeutic protein at a target site by providing a first population of mammalian cells transfected or transduced with a gene that is sought to be expressed, and a second population of mammalian cells that have not been transfected or transduced with the gene, wherein endogenously existing forms of the second population of mammalian cells are decreased at the target site, and wherein generation of the therapeutic protein by the first population of mammalian cells at the target site stimulates the second population cells to induce a therapeutic effect.