TRANSPLANTS COATED WITH AUTOLOGOUS ENDOTHELIAL CELLS

Abstract: The invention refers to a preparation intended to be transmitted to a recipient and including at least one foreign cell, producing a substance, from a donor. Said cell can for example produce substances being active with respect to a carrier, such as hormones, growth factors or transmitter substances. By coating said cell with endothelial cells that are derived from the recipient and that are attached to the surface of said cell in a way so they form a layer of endothelial cells, the risk of rejection when the foreign cell is transmitted to the recipient is reduced. The invention refers also to a method for producing said preparation, and a use of said preparation and a method for treatment of a disease or deficiency of a recipient by means of said preparation.

Description: TRANSPLANTS COATED WITH AUTOLOGOUS ENDOTHELIAL CELLS TRANSPLANTS COATED WITH AUTOLOGOUS ENDOTIELIAL CELLS The present invention refers to a preparation intended to be transmitted to a recipient and including at least one cell from a donor, said cell being of a type producing a substance. The invention also refers to a method for producing a preparation intended to be transmitted to a recipient and including at least one cell from a donor, said cell being of a type producing a substance. Moreover, the invention refers to a use of a preparation for treating a disease or deficiency of a recipient by transmitting the preparation, which comprises at least a cell from a donor, to the recipient, said cell being of a type producing a substance, as well as a method for treating a disease or deficiency of a recipient by means of a preparation being transmitted to the recipient and comprising at least one cell from a donor, said 'cell being of a type producing a substance. It is known that cells which produce active substances or biochemical factors could be transmitted from a donor to a recipient who suffers from deficiency of that substance or factor and to produce that substance or factor in the recipient to reduce said deficiency. One example of such a treatment is transplantation or transmission of pancreas cells from human beings or, for example, pigs to a patient who suffers from diabetes to increase the insulin production of the patient. Other examples are transplantation of cells from the brain, the adrenal glands, the thyroid gland, the liver etc. for treatment of different diseases. However, each individual of an animal or a human being has its own unique immunological identity. It results in that cells or organs may not be transmitted between different individuals without the foreign cells being attacked by the immunological system of the recipient and thereby being killed, or in other words being rejected. Consequently, also the above-mentioned examples of transmission or transplantation of different substance-producing cells can not be done to the extent that would be desirable for the treatment of different diseases. To solve the problems concerned with rejection arising in connection with transplantation, it has previously been proposed to coat the cells, which are to be transferred, with a synthetic layer, which prevents the cells from being attacked by the immunological system of the recipient. However, such a synthetic layer does not function completely satisfactory because all foreign substances are rejected from the recipient to a greater or less extent. The immunological effector cells which cause the rejection of foreign cells mentioned above are mainly bloodborne and normally exist in an inactive state. Activation of these effector cells can be attained in different ways but one quick way is when they are exposed to foreign endothelial cells. Endothelial cells are a cell type which in a continuous layer, the so-called the endothelium, completely cover the inside of the blood vessels, the lymphatic system and the heart. The layer is built of a monolayer of cells which together have an extensive surface. Consequently, the endothelial cells are strategical for the immunological effector cells of the recipient to identify and to reject if they are not autologous cells. WO96/40887 shows implants of foreign donor cells, as for example pancreas cells in a recipient, said donor cells being provided with an immunological barrier, which is produced, for example, by cartilage. It is mentioned in this document that the cartilage cells may be taken from the individual who is to receive donor cells but also that it is possible to take cartilage from other individuals. The cartilage cells are permitted to culture onto a matrix or some similar substrate so that a continuous layer of cartilage cells is formed. The donor cells which are to be inserted into a recipient are added onto this layer of cartilage cells and the layer is then folded over the donor cell in such a manner that a kind of packaging is formed which then is transplanted to a recipient by use of standard surgical techniques. WO94/03586 shows a way of detaching cells such as endothelial cells from their substrate. As an example is mentioned that the endothelial cells obtained may be used to coat tissue implant or prothesis in order to reduce the rejection when these are inserted into a receiving individual. WO94/07432 shows a novel synthetic implant that has a determined porosity. This document point to the possibility to provide endothelial cells onto such a synthetic porous implant. SUMMARY OF THE INVENTION The object of the present invention is to provide ways of reducing rejection reactions of a recipient to whom foreign cells are supplied. This object is obtained by the preparation initially defined and characterized in that said cell is coated with endothelial cells which are derived from the recipient and which are attached to the surface of said cell in such a way that they form a layer of endothelial cells. Such a preparation of cells which are coated with the recipient's own endothelial cells ought to reduce essentially the activation of the immunological effector cells of the recipient and thereby reduce the rejection process. Consequently, it is possible by the preparation according to the invention to transmit or to implant all possible cells from a donor into a patient who suffers from lack of a substance produced by such cells. Accordingly, the invention makes way for a better treatment in the future of diseases or deficiencies that are difficult to treat today. In case the preparation comprises a whole organ, which is to be transplanted, endothelial cells of the recipient will, according to the invention, replace the endothelial cells of the donor of said organ. Thereby, the endothelial cells preferably form a monolayer of cells, which covers substantially the whole surface of said cell. According to an embodiment of the invention, said cell comprises a type of cell which produces a substance being active with respect to a carrier. One example of active substances or biochemical factors is according to the invention hormones. For example such hormones may be insulin, growth hormone, thyroid hormone or glucose and mineral ocorticoid. Furthermore, said cell may comprise a type of cell, which produces growth factors or a type of cell, which produces transmitter substances, for example dopamine. According to a preferred application of the preparation according to the invention said recipient is a human being or an animal, as well as said donor. According to a further embodiment of the invention, the preparation is available in form of a solution. Thereby, the preparation may be stored in a suitable way and at the same time be transmitted to a recipient in a simple and conventional way, for example by injection into the bloodstream or the ventricle system of the brain, injection into or supply in any other way to the abdominal cavity, the pleurae, the heart sac or some other tissue. The preparation, according to the invention, may also comprise several cells in the form of a piece of tissue or a complete new organ. Such a piece of tissue coated with endothelial cells may then be inserted and placed in the body of the recipient by a standard surgical method. The object is also obtained by the method initially defined and characterized in that said cell is taken from the donor and is coated with endothelial cells which are derived from the recipient and are permitted to attach to the surface of said cell and form a layer of endothelial cells. Consequently, by such a method it is possible to achieve a preparation which can be transmitted to a patient and which results in a reduced risk of rejection of the preparation. According to an embodiment of the method, a number of endothelial cells are removed from the recipient and are cultured until a sufficient amount is available. Thereby, the cultured number of endothelial cells can be dissolved in a liquid and be poured onto said cell to be coated in such a way that a one-cell- layer of endothelial cells are formed, which covers substantially the whole surface of said cell. Said number of endothelial cells may be removed from the recipient by removing a piece of tissue from the recipient and by detaching the endothelial cells from this tissue by adding an enzyme. The detached endothelial cells are then dissolved, preferably in a liquid, which is poured onto a culturing dish. The object is also achieved by the use initially defined and characterized in that said cell is coated with endothelial cells which are derived from the recipient and are attached to the surface of said cell in such a way that they form a layer of endothelial cells, as well as by the method initially defined and characterized in that said cell is coated with endothelial cells which are derived from the recipient and are attached to the surface of said cell in such a way that they form a layer of endothelial cells. DESCRIPTION OF EXAMPLES The present invention will be described more closely with reference to the following examples. Example 1 From a patient, who suffers from diabetes and to whom insulin- producing cells from a donor, for example a pig, are to be transmitted, a piece of tissue is removed , for example a piece of blood-vessel tissue. This piece of tissue may be a piece of vein with a size of about 3 cm. Onto this piece of tissue a liquid containing an enzyme is applied which causes the detachment of the endothelial cells that exist on the vein-tissue. The achieved solution of endothelial cells is poured into a test tube and is centrifugalized so that the enzyme can be removed. Then the endothelial cells are suspended or dissolved in a culturing medium, wherein they have a substantially sphere-like shape. Then, the culturing medium is poured onto a culturing dish. Therein, the endothelial cells will attach to the culturing dish and grow, and be distributed over the surface of the culturing dish. During the growth, the endothelial cells take a substantially flat, extended shape. When this has occurred , the endothelial cells are detached from the culturing dish in the same way as from the vein tissue and the process is repeated in this way until a sufficient amount of endothelial cells are available. The cells to be transplanted are removed from the pancreas of the donor in a manner known per se and are transferred to a container. A solution of endothelial cells is poured over the pancreas cells from the donor, wherein the substantially sphere- shaped endothelial cells will attach to the surface of the pancreas cells and be distributed over the same until the whole surface of the pancreas cells is covered with a one-cell-layer of autologous endothelial cells. Also in this case, the endothelial cells will grow and take a substantially flat, extended shape on the surface of the pancreas cells. The coated pancreas cells are then transmitted to the patient who is to be treated against diabetes, for example by injection of a solution which comprises these cells coated by endothelial cells. Example 2 According to an other possible example of the invention a piece of brain tissue is removed from a donor. It may for example be a brain tissue comprising cells, which produce the transmitter substance dopamine. The solution with autologous endothelial cells obtained, according to example 1 , is then poured over this piece of brain tissue, wherein the endothelial cells will coat the whole surface of the piece of tissue. The piece of tissue can then be inserted and be placed in the brain of a patient who suffers from the deficiency of this transmitter substance. The applicant has in a laboratory been able to show that endothelial cells on blood-vessels from a pig and a human being can be removed from and replaced by endothelial cells which have been cultured from another human being. These new endothelial cells present the same biological properties as the original endothelial cells and accept their new underlying tissue without showing any signs on any remarkable activation of the immunological signalling system to potential immunological effector cells. It means in other words that the underlying tissue is regarded as the bodies own because it is covered with autologous endothelial cells. The invention is not limited to the examples disclosed above but may be varied and modified within the scope of the following claims. It is to be noted that a preparation according to the present invention might be produced from all cells from animals and human beings which would be desirable to transplant or transfer to another human being or another animal. It is also possible within the scope of the invention to produce whole organs from a recipient for transplantation to a receiving patient, wherein the organ concerned is coated with autologous endothelial cells of the recipient in accordance with the method which has been described above, before the organ is transplanted into a recipient.

Claims: Claims 1 . A preparation intended to be transmitted to a recipient and including at least one cell from a donor, said cell being of a type producing a substance, characterized in that said cell is coated with endothelial cells which are derived from the recipient and which are attached to the surface of said cell in such a way that they form a layer of endothelial cells. 2. A preparation according to claim 1 , characterized in that the endothelial cells form a one-cell-layer which covers substantially the whole surface of said cell. 3. A preparation according to any one of claims 1 and 2, characterized in that said cell comprises a type of cell which produces a substance being active with respect to a carrier. 4. A preparation according ' to claim 3, characterized in that said cell is of a type producing hormones. 5. A preparation according to claim 3, characterized in that said cell comprises a type of cell that produces growth factors. 6. A preparation according to claim 3, characterized in that said cell comprises a type of cell producing transmitter substances. 7. A preparation according to any one of the preceding claims, characterized in that said recipient is a human being or an animal. 8. A preparation according to any one of the preceding claims, characterized in that said donor is a human being or an animal. 9. A preparation according to any one of the preceding claims, characterized in that the preparation is available in form of a solution. 10. A preparation according to any one of the preceding claims, characterized in that it comprises several cells in form of a piece of tissue. 1 1. A method for producing a preparation intended to be transmitted to a recipient and including at least one cell from a donor, said cell being of a type producing a substance, characterized in that said cell is taken from the donor and is coated with endothelial cells which are derived from the recipient and are permitted to attach to the surface of said cell and form a layer of endothelial cells. 12. A method according to claim 1 1 , characterized in that a number of endothelial cells are removed from the recipient and are cultured until a sufficient amount is available. 13. A method according to claim 12, characterized in that the cultured number of endothelial cells are dissolved in a liquid and are poured onto said cell to be coated in such a way that a one- cell-layer is formed, which covers substantially the whole surface of said cell. 14. A method according to any one of claims 1 1 and 13, characterized in that said number of endothelial cells is removed from the recipient by removing a piece of tissue from the recipient and that endothelial cells are detached from that tissue by adding an enzyme. 15. A method according to claim 14, characterized in that the detached endothelial cells are dissolved in a liquid, which is poured onto a culturing dish. 16. Use of a preparation for treating a disease or deficiency of a recipient by transmitting the preparation, which comprises at least one cell from a donor, to the recipient, said cell being of a type producing a substance, characterized in that said cell is coated with endothelial cells which are derived from the recipient and are attached to the surface of said cell in such a way that they form a layer of endothelial cells. 17. Use according to claim 16, characterized in that the endothelial cells form a one-cell-layer that covers substantially the whole surface of said cell. 18. Use according to claim 17, characterized in that said cell comprises a type of cell that produces a substance being active with respect to a carrier. 19. Use according to claim 18, characterized in that said cell is of a type producing hormones. 20. Use according to claim 18, characterized in that said cell comprises a type of cell producing growth factors. 21 . Use according to claim 18, characterized in that said cell comprises a type of cell producing transmitter substances. 22. Use according to any one of claims 16 to 21 , characterized in. that said recipient is a human being or an animal. 23. Use according to any one of claims 16 to 22, characterized in. that said donor is a human being or an animal. 24. A method for treating a disease or deficiency of a recipient with a preparation being transmitted to the recipient and comprising at least one cell from a donor, said cell being of a type producing a substance, characterized in that said cell is coated with endothelial cells which are derived from the recipient and are attached to the surface of said cell in such a way that they form a layer of endothelial cells. 25. A method according to claim 24, characterized in that the endothelial cells form a one-cell-layer that covers substantially the whole surface of said cell. 26. A method according to any one of the claims 24 to 25, characterized in that said cell comprises a type of cell which produces a substance being active with respect to a carrier. 27. A method according to claim 26, characterized in that said cell comprises a type of cell producing hormones. 28. A method according to claim 26, characterized in that said cell comprises a type of cell producing growth factors. 29. A method according to claim 26, characterized in that said cell comprises a type of cell producing transmitter substances. 30. A method according to any one of the claims 24 to 29, characterized in that said recipient is a human being or an animal. 31 . A method according to any one of the claims 24 to 30, characterized in that said donor is a human being or an animal. 32. A method according to any one of the claims 24 to 31 , characterized in that preparation is injected into said recipient.

Inventors: BENGTSSON LARS, BENGTSSON, LARS
Applicants: BENGTSSON LARS, CARDIA INNOVATION AB, BENGTSSON, LARS
Application year: 1998
Main classification: A61K2
IPC codes: A61K35, C12N5