Preparation of conditionally immortalized immortalization-helper cells, used to immortalize mammalian cells, e.g. for production of hybridomas

摘要

Preparation of conditionally immortalized immortalization-helper cells (A; fusems) is new. Preparation of conditionally immortalized immortalization-helper cells (A; fusems) comprises at least: (i) introducing immortalizing genes (I) into mammalian cells so that expression and/or function of at least one (I) is regulatable, resulting in conditionally immortalized cells; (ii) introducing at least two selection markers (SM), for positive and negative selection, to allow selection between (A), cells to be immortalized with (A) and cells that have been immortalized with (A); and (iii) selection of cells (fusems) which contain SM and are conditionally immortalized. Independent claims are also included for the following: (a) fusem cells that are conditionally immortalized mammalian cells that contain at least two SM for selection; (b) method for immortalizing mammalian cells by transfer of the immortalizing characteristic from fusem to a cell (B) that is to be immortalized, and selecting for transfer of this characteristic; (c) hybridoma (C) comprising the fusion product of a fusem and (B); (d) use of (C) for stimulation of T cells so that they can recognize non-fused tumor cells; (e) method for producing T cells directed against a tumor; and (f) production of (C) from a fusem and lymphocyte.