Claims for Patent: 5,776,744

Summary for Patent: 5,776,744

Title:	Methods and compositions for effecting homologous recombination
Abstract:	Methods, compositions and kits for effecting homologous recombination are described. In one aspect, the method utilizes two introduced DNAs: (1) a mutagen-linked single-stranded oligonucleotide capable of specifically binding to double-stranded DNA to form a triple-stranded helix, and (2) a donor DNA fragment capable of undergoing homologous recombination with DNA targeted by the oligonucleotide.
Inventor(s):	Glazer; Peter M. (Guilford, CT), Lin; L. Michael (Wilmington, DE), George; Jay (Gaithersburg, MD)
Assignee:	Yale University (New Haven, CT) Codon Pharmaceuticals, Inc. (Gaithersburg, MD)
Application Number:	08/467,126
Patent Claims:	1. A method for effecting homologous recombination between a native nucleic acid segment in a cell and a donor nucleic acid segment introduced into the cell, which comprises: a) introducing into a cell: i) an oligonucleotide third strand which comprises a base sequence capable of forming a triple helix at a binding region on one or both strands of a native nucleic acid segment in the vicinity of a target region where the recombination is to occur, said oligonucleotide being capable of inducing homologous recombination at the target region of the native nucleic acid, and ii) a donor nucleic acid which comprises a nucleic acid sequence sufficiently homologous to the native nucleic acid segment such that the donor sequence is capable of undergoing homologous recombination with the native sequence at the target region; b) allowing the oligonucleotide to bind to the native nucleic acid segment to form a triple stranded nucleic acid, thereby inducing homologous recombination at the native nucleic acid segment target region; and c) allowing homologous recombination to occur between the native and donor nucleic acid segments wherein the oligonucleotide third strand has a dissociation constant for the binding region of less than or equal to about 10.sup.-7 M. 2. The method of claim 1, wherein the oligonucleotide third strand is from about 7 to about 50 nucleotides in length. 3. The method of claim 2, wherein the oligonucleotide third strand is from about 10 to about 30 nucleotides in length. 4. The method of claim 1, wherein the oligonucleotide third strand contains an at least partially artificial backbone. 5. The method of claim 1, wherein the oligonucleotide third strand contains a backbone selected from the group consisting of phosphodiester, phosphorothioate, methyl phosphonate, peptide, and mixtures thereof. 6. The method of claim 5, wherein the backbone is phosphodiester. 7. The method of claim 1, wherein the oligonucleotide third strand is modified with one or more protective groups. 8. The method of claim 7, wherein the 3' and 5' ends of the oligonucleotide third strand are modified with one or more protective groups. 9. The method of claim 7, wherein the protective group is selected from the group consisting of alkyl amines, acridine and cholesterol. 10. The method of claim 1, wherein the oligonucleotide third strand is circularized. 11. The method of claim 1, wherein the oligonucleotide third strand contains at least one modified sugar. 12. The method of claim 1, wherein the oligonucleotide third strand comprises at least one synthetic base. 13. The method of claim 1, wherein the dissociation constant is less than or equal to about 2.times.10.sup.-8 M. 14. The method of claim 1, wherein the oligonucleotide third strand has linked thereto a moiety which induces the homologous recombination. 15. The method of claim 14, wherein the moiety is linked to the oligonucleotide directly. 16. The method of claim 14, wherein the moiety is linked to the oligonucleotide through a linker. 17. The method of claim 14, wherein the moiety is selected from the group consisting of acridine, psoralen, a substituted psoralen, hydroxymethylpsoralen, mitomycin C, 1-nitrosopyrene, a nuclease, a restriction enzyme, a radionuclide, boron, and iodine. 18. The method of claim 1, wherein the donor nucleic acid is double stranded. 19. The method of claim 1, wherein the donor nucleic acid is single stranded. 20. The method of claim 1, wherein the donor nucleic acid comprises two substantially complementary single strands. 21. The method of claim 1, wherein the donor nucleic acid is substantially homologous with the native nucleic acid. 22. The method of claim 21, wherein the donor nucleic acid is substantially homologous with the native nucleic acid in a region of about 20 bases at each end of the donor nucleic acid. 23. The method of claim 1, wherein the donor nucleic acid is at least about 40 bases in length. 24. The method of claim 23, wherein the donor nucleic acid is between about 40 and about 40,000 bases in length. 25. The method of claim 1, wherein the donor nucleic acid is introduced into the cell in the form of a packaging system. 26. The method of claim 25, wherein the packaging system is selected from the group consisting of a DNA virus, an RNA virus, and a liposome. 27. The method of claim 1, wherein the native nucleic acid contains a mutation that is corrected by the homologous recombination. 28. The method of claim 27, wherein the mutation is selected from the group consisting of base changes, deletions, insertions, nucleotide repeats, and combinations thereof. 29. The method of claim 1, wherein the homologous recombination causes an alteration in the native nucleic acid sequence. 30. The method of claim 29, wherein the alteration is an addition of a segment selected from the group consisting of a gene, a part of a gene, a gene control region, an intron, a splice junction, a transposable element, a site specific recombination sequence, and combinations thereof. 31. The method of claim 1, wherein the native nucleic acid is chromosomal. 32. The method of claim 1, wherein the native nucleic acid is extrachromosomal. 33. The method of claim 32, wherein the native nucleic acid is selected from the group consisting of mitochondrial, episomal, a plasmid and a chloroplast. 34. A method for effecting homologous recombination between a first nucleic acid segment in a cell and a donor nucleic acid segment introduced into the cell, which comprises: a) contacting a donor nucleic acid segment with an oligonucleotide third strand which comprises a base sequence capable of forming a triple helix at a binding region on one or both strands of the donor nucleic acid segment in the vicinity of a target region where the recombination is to occur, said oligonucleotide being capable of inducing homologous recombination at the target region of the donor nucleic acid, and said donor having a sequence sufficiently homologous to a first nucleic acid segment such that the donor sequence will undergo homologous recombination with the first sequence at the target region; b) allowing the oligonucleotide to bind to the donor nucleic acid segment to form a triple stranded nucleic acid, thereby treating the donor nucleic acid segment to make it capable of inducing homologous recombination at the donor nucleic acid segment target region; c) introducing into a cell the treated donor nucleic acid; and d) allowing homologous recombination to occur between the first and donor nucleic acid segments wherein the oligonucleotide third strand has a dissociation constant for the binding region of less than or equal to about 10.sup.-7 M.

Details for Patent 5,776,744

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		2039-02-26
Merck Sharp & Dohme Corp.	INTRON A	interferon alfa-2b	For Injection	103132			2039-02-26
Merck Sharp & Dohme Corp.	INTRON A	interferon alfa-2b	Injection	103132			2039-02-26