Reivindicaciones
1. A method of making a population of reverse-immortalised human olfactory ensheathing glia (OEG) cells, which have the ability to promote axonal regeneration from adult CNS neurons, for transplantation into a patient, which comprises: a) providing a sample obtained from primary human OEG cells; b) immortalizing the OEG cells by transforming the OEG cells with a DNA construct comprising a removable DNA segment containing an oncogene or combination of oncogenes, thereby producing immortalised OEG cells; c) growing the immortalised OEG cells; d) selecting those immortalised OEG clonal cell lines which maintain the property of promoting axonal regeneration from adult CNS neurons; and e) removing the oncogene or combination of oncogenes from the immortalised OEG cells, the removal resulting in the production of the population of human OEG cells for transplantation into the patient. 2. The method of claim 1, wherein the oncogene or combination of oncogenes is made removable by flanking it with recombinase target sites, and the removing is accomplished by introducing into the immortalised cells a gene that is expressed to produce a recombinase that specifically recognizes the recombinase target sites. 3. The method of claim 2, wherein the recombinase is Cre recombinase and the recombinase target sites are loxP sites. 4. The method of claim 1, wherein the oncogene is the gene encoding SV40 large T antigen, the gene encoding telomerase catalytic subunit, the gene encoding Bmi-1 protein or any combination of said oncogenes. 5. The method of claim 1, wherein the removable DNA segment further contains a suicide gene, which encodes a gene product that enables destruction of the immortalised cells by an exogenous agent if the removable DNA segment is not removed from the cells. 6. The method of claim 5, wherein the suicide gene is a gene encoding herpes simplex virus thymidine kinase, and the cells are destroyed by exposure to gancyclovir if the removable DNA segment is not removed from the cells. 7. A population of reverse-immortalised human OEG cells, which have the ability to promote axonal regeneration, producible by the method of claim 1. 8. A population of reverse-immortalised human OEG cells, which have the ability to promote axonal regeneration, producible by the method of claim 1 for use as a medicament. 9. The use of a population of reverse-immortalised human OEG cells, which have the ability to promote axonal regeneration, producible by the method of claim 1 for the manufacture of a medicament for the treatment of neural damage wherein the medicament comprises a sufficient quantity of the human OEG cells of claim 7 for transplanting into the patient to provide promotion of neuronal regeneration in the neuronal injured region of the patient. 10. A method of making a population of reverse-immortalised human OEG cells, which have the ability to promote axonal regeneration from adult CNS neurons, for transplanting into a patient, which comprises: a) providing a sample obtained from primary human OEG cells; b) immortalizing the OEG cells by transforming the OEG cells with a DNA construct comprising a removable DNA segment containing an oncogene or a combination of oncogenes, a selectable marker gene, and a gene encoding herpes simplex virus thymidine kinase, the genes together being flanked on either side by loxP sites; c) growing the immortalised human OEG cells; d) selecting those immortalised OEG clonal cell lines which maintain the property of promoting axonal regeneration from adult CNS neurons; and e) reversing the immortalization of the human OEG cells by removing the DNA segment from the immortalised OEG cells, the removing being accomplished by introducing into the immortalised OEG cells a gene encoding Cre recombinase to effect excision of the DNA segment at the loxP sites, the excision resulting in the production of the population of human OEG cells for transplanting into a patient. 11. The method of claim 10, wherein the oncogene is the gene encoding SV40 large T antigen, the gene encoding telomerase catalytic subunit, the gene encoding Bmi-1 protein or any combination of said oncogenes. 12. A population of reverse-immortalised human OEG cells, which have the ability to promote axonal regeneration from adult CNS neurons, producible by the method of claim 10. 13. A population of reverse-immortalised human OEG cells, which have the ability to promote axonal regeneration from adult CNS neurons, producible by the method of claim 10 for use as a medicament. 14. The use of a population of reverse-immortalised human OEG cells, which have the ability to promote axonal regeneration from adult CNS neurons, producible by the method of claim 10 in the manufacture of a medicament for the treatment of neural damage wherein the medicament comprises a sufficient quantity of the OEG cells of claim 12 for transplanting into the patient to provide promotion of neuronal regeneration in the neuronal injured region. 15. A reverse-immortalised human OEG cell, which has the ability to promote axonal regeneration from adult CNS neurons, comprising a primary human OEG cell transformed with a DNA construct comprising two recombinase target sites that flank an oncogene or combination of oncogenes which confers immortalization to the OEG cell, wherein the immortalization is reversible by excision of the DNA construct by cleavage at the recombinase target sites when the target sites are exposed to a recombinase that specifically recognizes the target sites. 16. The reverse-immortalised OEG cell of claim 15, wherein the recombinase target sites are loxP sites and the immortalization is reversible by Cre recombinase cleavage at the loxP sites. 17. The reverse-immortalised OEG cell of claim 15, wherein the DNA construct further comprises a selectable marker gene. 18. The reverse-immortalised OEG cell of claim 15, wherein the DNA construct further comprises a suicide gene, which encodes a gene product that enables destruction of the immortalised OEG cell by an exogenous agent if the oncogene is not removed from the cells. 19. The reverse-immortalised OEG cell of claim 18, wherein the suicide gene is a gene encoding herpes simplex virus thymidine kinase, and the exogenous agent is gancyclovir. 20. A cell line comprising a population of the reverse-immortalised human OEG cells of claim 15. 21. A reverse-immortalised human OEG cell which has the ability to promote axonal regeneration from adult CNS neurons upon transplantation into a patient, producible by exposing the DNA construct within the immortalised human OEG cell of claim 15 to a recombinase that excises the DNA construct by cleavage at the recombinase target sites. 22. A reverse-immortalised human OEG cell which has the ability to promote axonal regeneration from adult CNS neurons upon transplantation into a patient, producible by exposing the DNA construct within the immortalised human OEG cell of claim 15 to a recombinase that excises the DNA construct by cleavage at the recombinase target sites for use as a medicament. 23. The use of a reverse-immortalised human OEG cell which has the ability to promote axonal regeneration from adult CNS neurons upon transplantation into a patient, producible by exposing the DNA construct within the immortalised human OEG cell of claim 15 to a recombinase that excises the DNA construct by cleavage at the recombinase target sites in the manufacture of a medicament for the treatment of neural damage, wherein the medicament comprises a sufficient quantity of the reverse-immortalised OEG human cells of claim 21 for transplanting into the patient to provide promotion of neuronal regeneration in the neuronal injured region of the patient. 24. A cell library comprising a population of reverse-immortalised human OEG cells which have the ability to promote axonal regeneration from adult CNS neurons, producible according to the methods of any one of claims 1 to 6 or 10 to 11. 25. A reverse immortalised human olfactory ensheathing glia (OEG) cell line, which has the ability to promote axonal regeneration from adult CNS neurons comprising a primary human OEG cell transformed with a DNA construct comprising two recombinase target sites that flank an oncogene or combination of oncogenes which confers immortalization to the OEG cell, wherein the immortalization is reversible by excision of the DNA construct by cleavage at the recombinase target sites when the target sites are exposed to a recombinase that specifically recognizes the target sites. 26. A cell line according to claim 25, for use in a method of therapy. 27. A cell line according to claim 25, for use in promoting neuronal regeneration. 28. A pharmaceutical composition comprising a human OEG cell line as defined in claims 25-27, and a pharmaceutically acceptable carrier. 29. The use of reverse-immortalised human olfactory ensheathing glia cells which have the ability to promote axonal regeneration from adult CNS neurons as defined in claims 7, 13, 22 or 25 in the preparation of a medicament for treating neuronal damage.
