Production of a canine beta cell line from an immature pancreas

A method of preparing canine pancreatic beta cells or canine beta cell tumours, comprising the steps of:

• a) transducing or co-transducing immature canine pancreas cells with i) a lentiviral vector encoding SV40 LargeT antigen under the control of the insulin promoter, or ii) with a lentiviral vector encoding SV40 LargeT antigen under the control of the insulin promoter and a lentiviral vector encoding hTert under the control of the insulin promoter, or iii) a lentiviral vector encoding both SV40 LargeT antigen and hTert under the control of the insulin promoter wherein the immature canine pancreas cells are obtained from a foetal canine pancreas at days 40 to 60 post conception;
• b) introducing the transduced immature pancreas cells obtained in a) into the kidney capsule of a first severe combined immunodeficiency (scid) mouse;
• c) allowing the transduced immature pancreas cells to develop insulinoma-like structures, wherein the canine pancreas cells in insulinoma-like structures have differentiated to insulin-producing pancreatic beta cells;
• d) micro-dissecting the insulinoma-like structures obtained in step c), and dissociating the cells thereof;
• e) sub-transplanting the cells obtained in step d) into the kidney capsule of a second scid mouse;
• f) allowing the sub-transplanted cells in step e) to develop and regenerate newly developed insulinoma-like structures, wherein said newly developed insulinoma-like structures are enriched in insulin-producing pancreatic beta cells;
• g) micro-dissecting the insulinoma-like structures obtained in step f), and dissociating and collecting the cells thereof.