Claims for Patent: 6,159,710

Summary for Patent: 6,159,710

Title:	Method and compositions for stabilizing unstable gene transcripts
Abstract:	A polynucleotide molecule useful for stably producing a gene product includes a polynucleotide sequence encoding the gene product (or alternatively a gene transcript) flanked by a 5\' sequence and a 3\' of an intron. Methods and compositions using this molecule permit enhanced recombinant expression of the gene product and are particularly useful in stabilizing unstable mRNA transcripts, permitting the stable production of desirable genes encoded thereby. Vectors and host cells containing this molecule are useful in the methods.
Inventor(s):	Fraser; Nigel W. (Merion Station, PA), Zabolotny; Janice M. (Brookline, MA), Krummenacher; Claude F. (Philadelphia, PA)
Assignee:	The Wistar Institute of Anatomy and Biology (Philadelphia, PA)
Application Number:	09/403,267
Patent Claims:	1. A polynucleotide molecule comprising: (a) a polynucleotide sequence encoding a gene product; (b) a 5' sequence of an intron comprising the splice donor and splice acceptor of said intron; (c) a 3' sequence of said intron comprising a hairpin structure adjacent to the branchpoint of said intron; wherein the sequence (a) is flanked by the sequences (b) and (c), and wherein said polynucleotide molecule stably expresses said gene product in culture. 2. The molecule according to claim 1 further comprising an internal ribosome entry site. 3. The molecule according to claim 1, consisting of RNA. 4. The molecule according to claim 1, consisting of DNA. 5. The molecule according to claim 1 wherein said hairpin is 5' to said branchpoint. 6. The molecule according to claim 1 wherein said hairpin is 3' to said branchpoint. 7. The molecule according to claim 1 wherein said intron is the 2.0 kb LAT of a herpes virus. 8. The molecule according to claim 7 comprising, from 5' to 3': (a) a polynucleotide sequence comprising a 5' sequence of the 2.0 kb LAT of a herpes virus; (b) a polynucleotide sequence comprising an internal ribosome entry site; (c) a polynucleotide sequence comprising an open reading frame encoding a selected gene product; and (d) a polynucleotide sequence comprising a 3' sequence of the 2.0 kb LAT of a herpes virus. 9. The molecule according to claim 7 wherein said 5' sequence (b) comprises a polynucleotide sequence spanning from about 2 to about 20 nucleotides 5' to the 5' nucleotide of said 2.0 kb LAT through about 2 to about 20 nucleotides 3' to said 5' nucleotide. 10. The molecule according to claim 7 wherein said 3' sequence (c) comprises a polynucleotide sequence of about 80 nucleotides. 11. The molecule according to claim 7 wherein said 3' sequence (c) comprises a polynucleotide sequence spanning from about 75 to about 300 nucleotides 5' to the 3' nucleotide of said 2.0 kb LAT through about 2 to about 20 nucleotides 3' to said 3' nucleotide. 12. The molecule according to claim 11 wherein said 3' sequence (c) comprises a polynucleotide sequence spanning from about 300 nucleotides 5' to the 3' nucleotide of said 2.0 kb LAT through about 2 to about 20 nucleotides 3' to said 3' nucleotide. 13. The molecule according to claim 11 wherein said 3' sequence (c) comprises a polynucleotide sequence spanning from about 200 nucleotides 5' to the 3' nucleotide of said 2.0 kb LAT through about 2 to about 20 nucleotides 3' to said 3' nucleotide. 14. The molecule according to claim 11 wherein said 3' sequence (c) comprises a polynucleotide sequence spanning from about 150 nucleotides 5' to the 3' nucleotide of said 2.0 kb LAT through about 2 to about 20 nucleotides 3' to said 3' nucleotide. 15. The molecule according to claim 1 wherein said 3' sequence (c) comprises a splice acceptor sequence. 16. The molecule according to claim 2 wherein said internal ribosome entry site sequence is a viral sequence. 17. The molecule according to claim 16 wherein said ribosome entry site sequence is the EMC virus internal ribosome entry site sequence. 18. The molecule according to claim 2 wherein said internal ribosome entry sequence is a mammalian sequence. 19. The molecule according to claim 18 wherein said internal ribosome entry site sequence is BiP. 20. The molecule according to claim 1 further comprising a promoter sequence located 5' to said sequence (b) and operably linked within said molecule to direct expression of said selected gene in a host cell. 21. The molecule according to claim 1 wherein said selected gene is an unstable transcript. 22. The molecule according to claim 21 wherein said selected gene encodes a protooncogene. 23. The molecule according to claim 1 wherein said selected gene encodes a growth factor. 24. An expression vector comprising: (a) a polynucleotide sequence encoding a gene product; (b) a 5' sequence of an intron comprising the splice donor and splice acceptor of said intron; (c) a 3' sequence of said intron comprising a hairpin structure adjacent to the branchpoint of said intron; wherein the sequence (a) is flanked by the sequences (b) and (c); and wherein said sequence (a) is under the control of regulatory sequences which direct stable expression of said gene product in a host cell. 25. A host cell transfected with a vector of claim 24. 26. A method for stably expressing an unstable gene transcript to permit enhanced expression of said gene product, the method comprising the steps of: culturing a host cell transfected with an expression vector comprising: (a) a polynucleotide sequence encoding a gene product; (b) a 5' sequence of an intron comprising the splice donor and splice acceptor of said intron; and (c) a 3' sequence of said intron comprising a hairpin structure adjacent to the branchpoint of said intron; wherein the sequence (a) is flanked by the sequences (b) and (c); and wherein said sequence (a) is under the control of regulatory sequences which direct stable expression of said gene product in a host cell; and isolating the product of said gene from the cytoplasm of said host cell or from said culture. 27. A method for stably expressing a gene having an unstable mRNA in a cell comprising infecting said cell with a stable polynucleotide molecule comprising: (a) a polynucleotide sequence comprising said unstable mRNA; (b) a 5' sequence of an intron comprising the splice donor and splice acceptor of said intron; (c) a 3' sequence of said intron comprising a hairpin structure adjacent to the branchpoint of said intron; wherein the sequence (a) is flanked by the sequences (b) and (c), and wherein said molecule comprises regulatory sequences which direct stable expression of said gene in said cell.

Details for Patent 6,159,710

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Merck Sharp & Dohme Corp.	INTRON A	interferon alfa-2b	For Injection	103132	06/04/1986		2017-04-18
Merck Sharp & Dohme Corp.	INTRON A	interferon alfa-2b	For Injection	103132			2017-04-18
Merck Sharp & Dohme Corp.	INTRON A	interferon alfa-2b	Injection	103132			2017-04-18