An object of the present invention is to provide a method for immortalizing an
antibody-producing
cell; and an immortalized
transformed cell obtained by the method. The invention relates to a method for producing an immortalized
cell, the method including introducing SV40 T
antigen gene, genes of Bcl-2 family, and one or more genes selected from the group consisting of genes of Myc family and genes of
cyclin D family into a non-immortalized
antibody-producing
cell to produce an immortalized cell; and a method for producing an immortalized
antibody-producing cell, the method including collecting an antibody-producing cell from a
mammal and subjecting the cell to
primary culture; and introducing one or more genes selected from the group consisting of SV40 T
antigen gene, genes of Bcl-2 family, genes of Myc family, and genes of
cyclin D family into a primary antibody-producing cell thus obtained to produce an immortalized antibody-producing cell.