Patent ID: 6417002
Filing Date: 2002-07-09
Classification: C12N

Abstract:
A method for obtaining a self-selecting eukaryotic cell stably transfected in vitro with at least two episomes, which comprises(a) transfecting a eukaryotic cell with: (i) a first episome which comprises (a) an EBV origin of replication (oriP); (b) a nucleic acid sequence encoding a kill agonist wherein expression of said kill agonist in the absence of a kill antagonist results in cell death; and (c) a nucleic acid sequence encoding a selectable marker for eukaryotic cells; and (ii) a second episome comprising (a) an EBV origin of replication (oriP); and (b) a nucleic acid sequence encoding a kill antagonist wherein expression of said kill antagonist prohibits the occurrence of cell death resulting from expression of said kill agonist; to produce self-selecting transfected cells whereby exogenous selection factors are not required for continued maintenance and selection of the episomes in said cells and wherein said cells also express an antigen that promotes retention of the episomes by said cells; and (b) maintaining said cells under conditions in which said kill agonist, said kill antagonist and said selectable marker are expressed.