Cells in which activity of the protein involved in transportation of GDP-fucose is reduced or lost

• US 20040110282A1
• Filed: 04/09/2003
• Published: 06/10/2004
• Est. Priority Date: 04/09/2002
• Status: Active Grant

• Current Assignee: Kyowa Kirin Co., Ltd. (Kirin Holdings Company Limited)
• Original Assignee: Kyowa Hakko Kogyo Company Limited (Kirin Holdings Company Limited)
• Inventors: Satoh, Mitsuo, Kanda, Yutaka, Mori, Katsuhiro
• Granted Patent: US 7,749,753 B2
• Time in Patent Office: Days
• US Class Current: 435/325
• CPC Class Codes: A61K 2039/505 comprising antibodies
• CPC Class Codes: A61P 29/00 Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID]
• CPC Class Codes: A61P 31/00 Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
• CPC Class Codes: A61P 31/04 Antibacterial agents
• CPC Class Codes: A61P 31/12 Antivirals
• CPC Class Codes: A61P 35/00 Antineoplastic agents
• CPC Class Codes: A61P 37/00 Drugs for immunological or allergic disorders
• CPC Class Codes: A61P 37/08 Antiallergic agents antiasthmatic agents A61P11/06; ophthalmic antiallergics A61P27/14
• CPC Class Codes: A61P 9/00 Drugs for disorders of the cardiovascular system
• CPC Class Codes: C07K 14/47 from mammals
• CPC Class Codes: C07K 16/18 against material from animals or humans
• CPC Class Codes: C07K 16/2866 against receptors for cytokines, lymphokines, interferons
• CPC Class Codes: C07K 2317/24 containing regions, domains or residues from different species, e.g. chimeric, humanized or veneered
• CPC Class Codes: C07K 2317/732 Antibody-dependent cellular cytotoxicity [ADCC]
• CPC Class Codes: C12N 15/8245 involving modified carbohydrate or sugar alcohol metabolism, e.g. starch biosynthesis

Abstract

A cell in which the activity of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body is more decreased or deleted than its parent cell; a process for producing an antibody composition using the cell; a transgenic non-human animal or plant or the progenies thereof, in which genome is modified so as to have a decreased or deleted activity of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body; a process for producing an antibody composition from the animal or plant; and a medicament comprising the antibody composition.

Claims

1. A cell in which the activity of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body is more decreased or deleted than its parent cell.

2. The cell according to claim 1, wherein the activity of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body is decreased or deleted by a genetic engineering technique.

3. The cell according to any one of claims 2 to 5, wherein the genetic engineering technique is selected from the group consisting of (a) to (d):

(a) a gene disruption technique which comprises targeting a gene encoding a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body;

(b) a technique for introducing a dominant negative mutant of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body;

(c) a technique for introducing mutation into a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body;

(d) a technique for suprressing transcription and/or translation of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body.

4. The cell according to claim 3, wherein the dominant negative mutant of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body is an N-terminal deletion mutant of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body.

5. The cell according to claim 4, wherein the N-terminal deletion mutant of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body is an N-terminal deletion mutant in which 30 amino acids at the N-terminal of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body are deleted.

6. The cell according to claim 3, wherein the technique for suprressing transcription and/or translation of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body is an RNAi (RNA interference) method.

7. The cell according to claim 6, wherein a double-stranded RNA comprising an RNA and its comlementary RNA is introduced into or expressed in the cell, said RNA comprised in the double-stranded RNA being selected from the group consisting of the following (a) to (d) and being capable of decreasing the amount of mRNA of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body:

(a) an RNA corresponding to a DNA comprising a nucleotide sequence of continuous 10 to 30 nucleotides in the nucleotide sequence represented by SEQ ID NO;

1;

(b) an RNA corresponding to a DNA comprising a nucleotide sequence of continuous 10 to 30 nucleotides in the nucleotide sequence represented by SEQ ID NO;

3;

(c) an RNA corresponding to a DNA comprising a nucleotide sequence of continuous 10 to 30 nucleotides in the nucleotide sequence represented by SEQ ID NO;

29;

(d) an RNA corresponding to a DNA comprising a nucleotide sequence of continuous 10 to 30 nucleotides in the nucleotide sequence represented by SEQ ID NO;

30.

8. The cell according to claim 6 or 7, wherein the double-stranded RNA comprising a RNA selected from the group consisting of (a) and (b) and its complementary RNA is introduced into or expressed in the cell to thereby decrease the amount of mRNA of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body:

(a) an RNA comprising the nucleotide sequence represented by SEQ ID NO;

33;

(b) an RNA which comprises a nucleotide sequence in which one or a few nucleotide are deleted or added in the nucleotide sequence represented by SEQ ID NO;

33 and has substantially the same RNAi activity as the nucleotide sequence represented by SEQ ID NO;

33.

9. The cell according to claim 7 or 8, wherein the double-stranded RNA is introduced into the cell by using a vector into which a DNA corresponding to the RNA according to claim 7 or 8 and its complementary DNA are introduced.

10. The cell according to any one of claims 1 to 9, wherein the protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body is a GDP-fucose transporter.

11. The cell according to claim 10, wherein the GDP-fucose transporter is a protein encoded by a DNA selected from the group consisting of the following (a) to (h):

(a) a DNA comprising the nucleotide sequence represented by SEQ ID NO;

1;

(b) a DNA comprising the nucleotide sequence represented by SEQ ID NO;

3;

(c) a DNA comprising the nucleotide sequence represented by SEQ ID NO;

29;

(d) a DNA comprising the nucleotide sequence represented by SEQ ID NO;

30;

(e) a DNA which hybridizes with a DNA comprising the nucleotide sequence represented by SEQ ID NO;

1 under stringent conditions and having a GDP-fucose transporter activity;

(f) a DNA which hybridizes with a DNA comprising the nucleotide sequence represented by SEQ ID NO;

3 under stringent conditions and having a GDP-fucose transporter activity,

(g) a DNA which hybridizes with a DNA comprising the nucleotide sequence represented by SEQ ID NO;

29 under stringent conditions and having a GDP-fucose transporter activity,

(h) a DNA which hybridizes with a DNA comprising the nucleotide sequence represented by SEQ ID NO;

30 under stringent conditions and having a GDP-fucose transporter activity.

12. The cell according to claim 10, wherein the GDP-fucose transporter is a protein selected from the group consisting of the following (a) to (l):

(a) a protein comprising the amino acid sequence represented by SEQ ID NO;

2;

(b) a protein comprising the amino acid sequence represented by SEQ ID NO;

4;

(c) a protein comprising the amino acid sequence represented by SEQ ID NO;

31;

(d) a protein comprising the amino acid sequence represented by SEQ ID NO;

32;

(e) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ID NO;

2 and has a GDP-fucose transporter activity;

(f) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ID NO;

4 and has a GDP-fucose transporter activity;

(g) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ID NO;

31 and has a GDP-fucose transporter activity;

(h) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ E) NO;

32 and has a GDP-fucose transporter activity;

(i) a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

2 and has a GDP-fucose transporter activity;

(j) a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

4 and has a GDP-fucose transporter activity;

(k) a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

31 and has a GDP-fucose transporter activity;

(l) a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

32 and has a GDP-fucose transporter activity.

13. The cell according to any one of claims 1 to 12, which is resistant to a lectin which recognizes a sugar chain in which 1-position of fucose is bound to 6-position of N-acetylglucosamine in the reducing end through α

-bond in a complex N-glycoside-linked sugar chain.

14. The cell according to claim 13, which is resistant to at least one lectin selected from the group consisting of the following (a) to (d):

(a) a Lens culinaris lectin;

(b) a Pisum sativum lectin;

(c) a Vicia faba lectin;

(d) an Aleuria aurantia lectin.

15. The cell according to any one of claims 1 to 14, wherein the cell is selected from the group consisting of a yeast, an animal cell, an insect cell and a plant cell.

16. The cell according to any one of claims 1 to 15, which is selected from the group consisting of the following (a) to (j):

(a) a CHO cell derived from a Chinese hamster ovary tissue;

(b) a rat myeloma cell line YB2/3HL.P2.G11.16Ag.20 cell;

(c) a mouse myeloma cell line NS0 cell;

(d) a mouse myeloma cell line SP2/0-Ag14 cell;

(e) a BHK cell derived from a Syrian hamster kidney tissue;

(f) a hybridoma cell which produces an antibody;

(g) a human leukemic cell line Namalwa cell;

(h) an embryonic stem cell;

(i) a fertilized egg cell;

(j) a plant cell.

17. A cell in which a gene encoding an antibody molecule is introduced into the cell according to any one of claims 1 to 16.

18. The cell according to claim 17, wherein the antibody molecule is selected from the group consisting of the following (a) to (d):

(a) a human antibody;

(b) a humanized antibody;

(c) an antibody fragment comprising the Fc region of (a) or (b);

(d) a fusion protein comprising the Fc region of (a) or (b).

19. The cell according to claim 17 or 18, wherein the antibody molecule belongs to an IgG class.

20. The cell according to any one of claims 17 to 19, wherein the antibody composition has a higher antibody-dependent cell-mediated cytotoxic activity than an antibody composition produced by its parent cell.

21. The cell according to claim 20, wherein the antibody composition having a higher antibody-dependent cell-mediated cytotoxic activity has a higher ratio of a sugar chain in which fucose is not bound to N-acetylglucosamine in the reducing end in the sugar chain among total complex N-glycoside-linked sugar chains bound to the Fc region in the antibody composition than an antibody composition produced by its parent cell.

22. The cell according to claim 21, wherein the ratio of a sugar chain in which fucose is not bound to N-acetylglucosamine in the reducing end through α

-bond is 20% or more of total complex N-glycoside-linked sugar chains bound to the Fc region in the antibody composition.

23. The cell according to claim 21, wherein the sugar chain in which fucose is not bound is a sugar chain in which 1-position of fucose is not bound to 6-position of N-acetylglucosamine in the reducing end in the complex N-glycoside-linked sugar chain through α

-bond.

24. A process for producing an antibody composition, which comprises using the cell according to any one of claims 17 to 23.

25. A process for producing an antibody composition, which comprises culturing the cell according to any one of claims 17 to 23 in a medium to form and accumulate an antibody composition in the culture;

and recovering the antibody composition from the culture.

26. The process according to claim 24 or 25, wherein the antibody composition has a higher antibody-dependent cell-mediated cytotoxic activity than an antibody composition produced by its parent cell.

27. The process according to claim 26, wherein the antibody composition having a higher antibody-dependent cell-mediated cytotoxic activity has a higher ratio of a sugar chain in which fucose is not bound to N-acetylglucosamine in the reducing end in the sugar chain among total complex N-glycoside-linked sugar chains bound to the Fc region in the antibody composition than an antibody composition produced by its parent cell.

28. The process according to claim 27, wherein the ratio of a sugar chain in which fucose is not bound to N-acetylglucosamine in the reducing end through α

-bond is 20% or more of total complex N-glycoside-linked sugar chains bound to the Fc region in the antibody composition.

29. The process according to claim 27, wherein the sugar chain in which fucose is not bound is a sugar chain in which 1-position of the fucose is not bound to 6-position of N-acetylglucosamine in the reducing end through α

-bond in a complex N-glycoside-linked sugar chain.

46. An antibody composition produced by the process according to any one of claims 24 to 29.

48. A medicament comprising as an active ingredient the antibody composition according to claim 46 or 47.

49. The medicament according to claim 48, which diagnoses, prevents or treats tumor-accompanied diseases, allergy-accompanied diseases, inflammatory-accompanied diseases, autoimmune diseases, cardiovascular diseases, viral infection-accompanied diseases or bacterial infection-accompanied diseases.

30. A transgenic non-human animal or plant or the progenies thereof, in which genome is modified so as to have a decreased or deleted activity of a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body.

31. The transgenic non-human animal or plant or the progenies thereof according to claim 30, wherein a gene encoding a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body is knocked out.

32. The transgenic non-human animal or plant or the progenies thereof according to claim 31, wherein all allelic genes on a genome encoding a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body is knocked out.

33. The transgenic non-human animal or plant or the progenies thereof according to any one of claims 30 to 32, wherein the protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body is a GDP-fucose transporter.

34. The transgenic non-human animal or plant or the progenies thereof according to claim 33, wherein the GDP-fucose transporter is a protein encoded by a DNA selected from the group consisting of the following (a) to (h):

(a) a DNA comprising the nucleotide sequence represented by SEQ ID NO;

1;

(b) a DNA comprising the nucleotide sequence represented by SEQ ID NO-3;

(c) a DNA comprising the nucleotide sequence represented by SEQ ID NO;

29;

(d) a DNA comprising the nucleotide sequence represented by SEQ ID NO;

30;

(e) a DNA which hybridizes with a DNA comprising the nucleotide sequence represented by SEQ ID NO;

1 under stringent conditions and having a GDP-fucose transporter activity;

(f) a DNA which hybridizes with a DNA comprising the nucleotide sequence represented by SEQ ID NO;

3 under stringent conditions and having a GDP-fucose transporter activity;

(g) a DNA which hybridizes with a DNA comprising the nucleotide sequence represented by SEQ ID NO;

29 under stringent conditions and having a GDP-fucose transporter activity;

(h) a DNA which hybridizes with a DNA comprising the nucleotide sequence represented by SEQ ID NO;

30 under stringent conditions and having a GDP-fucose transporter activity.

35. The transgenic non-human animal or plant or the progenies thereof according to claim 33, wherein the GDP-fucose transporter is a protein selected from the group consisting of the following (a) to (l):

(a) a protein comprising the amino acid sequence represented by SEQ ID NO;

2;

(b) a protein comprising the amino acid sequence represented by SEQ ID NO;

4;

(c) a protein comprising the amino acid sequence represented by SEQ ID NO;

31;

(d) a protein comprising the amino acid sequence represented by SEQ ID NO;

32;

(e) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ID NO;

2 and has a GDP-fucose transporter activity;

(f) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ID NO;

4 and has a GDP-fucose transporter activity;

(g) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ID NO;

31 and has a GDP-fucose transporter activity;

(h) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ID NO;

32 and has a GDP-fucose transporter activity;

(i) a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

2 and has a GDP-fucose transporter activity;

a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

4 and has a GDP-fucose transporter activity;

(k) a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

31 and has a GDP-fucose transporter activity;

(l) a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

32 and has a GDP-fucose transporter activity.

36. The transgenic nonhuman animal or the progenies thereof according to any one of claims 30 to 35, wherein the transgenic non-human animal is selected from the group consisting of cattle, sheep, goat, pig, horse, mouse, rat, fowl, monkey and rabbit.

37. A transgenic non-human animal or plant or the progenies thereof in which a gene encoding an antibody molecule is introduced into the transgenic non-human animal or plant or the progenies thereof according to any one of claims 30 to 36.

38. The transgenic non-human animal or plant or the progenies thereof according to claim 37, wherein the antibody molecule is selected from the group consisting of the following (a) to (d):

(a) a human antibody;

(b) a humanized antibody;

(c) an antibody fragment comprising the Fc region of (a) or (b);

(d) a fusion protein comprising the Fc region of (a) or (b).

39. The transgenic non-human animal or plant or the progenies thereof according to claim 37 or 38, wherein the antibody molecule belongs to an IgG class.

40. A process for producing an antibody composition, which comprises rearing the transgenic non-human animal or plant or the progenies thereof according to any one of claims 37 to 39;

and recovering the desired antibody composition from the isolated tissue or body fluid.

41. A process for producing an antibody composition, which comprises isolating an antibody-producing cell from the transgenic non-human animal or plant or the progenies thereof according to any one of claims 37 to 39;

culturing the isolated antibody-producing cell in a medium to form and accumulate an antibody composition in a culture; and

recovering the antibody composition from the culture.

42. The process according to claim 40 or 41, wherein the antibody composition has a higher antibody-dependent cell-mediated cytotoxic activity than an antibody composition produced from a non-human animal or plant in which genome is not modified or the progenies thereof.

43. The process according to claim 42, wherein the antibody composition having a higher antibody-dependent cell-mediated cytotoxic activity has a higher ratio of a sugar chain in which fucose is not bound to N-acetylglucosamine in the reducing end in the sugar chain among total complex N-glycoside-linked sugar chains bound to the Fc region in the antibody composition than an antibody composition produced by a non-human animal or plant or the progenies thereof in which genome is not modified.

44. The process according to claim 43, wherein the ratio of a sugar chain in which fucose is not bound to N-acetylglucosamine in the reducing end through α

-bond is 20% or more of total complex N-glycoside-linked sugar chains bound to the Fc region in the antibody composition.

45. The process according to claim 43, wherein the sugar chain in which fucose is not bound is a sugar chain in which 1-position of the fucose is not bound to 6-position of N-acetylglucosamine in the reducing end through α

-bond in a complex N-glycoside-linked sugar chain.

47. An antibody composition produced by the process according to any one of claims 40 to 45.

70. Use of the antibody composition according to claim 43 or 44 in the manufacture of the medicament according to claim 48 or 49.

50. A protein which is selected from the group consisting of the following (a) and (b):

(a) a protein comprising the amino acid sequence represented by SEQ ID NO;

2;

(b) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ID NO;

2 and has a GDP-fucose transporter activity.

51. A DNA comprising the nucleotide sequence represented by SEQ ID NO:

1.

52. A target vector for homologous recombination which comprises targeting a GDP-fucose transporter, comprising the full length DNA represented by SEQ ID NO:

1 or a part thereof.

53. A protein which inhibits the function of a GDP-fucose transporter.

54. The protein according to claim 53, wherein the protein which inhibits the function of a GDP-fucose transporter is a dominant negative protein of a GDP-fucose transporter.

55. The protein according to claim 54, wherein the dominant negative protein of a GDP-fucose transporter is an N-terminal-deleted mutant of GDP-fucose transporter.

56. The protein according to claim 55, wherein the N-terminal-deleted mutant of GDP-fucose transporter is an N-terminal-deleted mutant of GDP-fucose transporter in which 30 amino acids are deleted from the N-terminal of the GDP-fucose transporter.

57. The protein according to any one of claims 53 to 56, wherein the GDP-fucose transporter is a protein selected from the group consisting of the following (a) to (l):

(a) a protein comprising the amino acid sequence represented by SEQ ID NO;

2;

(b) a protein comprising the amino acid sequence represented by SEQ ID NO;

4;

(c) a protein comprising the amino acid sequence represented by SEQ ID NO;

31;

(d) a protein comprising the amino acid sequence represented by SEQ ID NO;

32;

(e) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ID NO;

2 and has a GDP-fucose transporter activity;

(f) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ED NO;

4 and has a GDP-fucose transporter activity;

(g) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ID NO;

31 and has a GDP-fucose transporter activity;

(h) a protein which comprises an amino acid sequence in which at least one amino acid is deleted, substituted, inserted and/or added in the amino acid sequence represented by SEQ ID NO;

32 and has a GDP-fucose transporter activity;

(i) a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

2 and has a GDP-fucose transporter activity;

(j) a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

4 and has a GDP-fucose transporter activity;

(k) a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

31 and has a GDP-fucose transporter activity;

(l) a protein which comprises an amino acid sequence having a homology of at least 80% with the amino acid sequence represented by SEQ ID NO;

32 and has a GDP-fucose transporter activity.

58. A DNA encoding the protein according to any one of claims 53 to 57.

59. A double-stranded RNA comprising an RNA selected from the group consisting of (a) and (b) and its complementary RNA:

(a) an RNA comprising the nucleotide sequence represented by SEQ ID NO;

33;

(b) an RNA which comprises a nucleotide sequence in which one or a few nucleotide are deleted or added in the nucleotide sequence represented by SEQ ID NO;

33 and has substantially the same RNAi activity to a protein relating to transport of an intracellular sugar nucleotide, GDP-fucose, to the Golgi body as the nucleotide sequence represented by SEQ ID NO;

33.

60. A DNA corresponding to the RNA according to claim 59 and its complementary DNA.

61. The DNA according to claim 60, wherein the DNA corresponding to the RNA is represented by the nucleotide sequence represented by SEQ ID NO:

16.

62. A recombinant DNA comprising the DNA according to claim 60 or 61 and its complementary DNA.

63. The recombinant DNA according to claim 62, which is constituted for expressing the double-stranded RNA according to claim 59.

64. A transformant obtainable by introducing the recombinant DNA according to claim 62 or 63 into a cell.

65. A process for producing a cell resistant to a lectin which recognizes a sugar chain in which 1-position of fucose is bound to 6-position of N-acetylglucosamine in the reducing end through α

-bond in a complex N-glycoside-linked sugar chain, which comprises introducing into and/or expressing in a cell the double-stranded RNA according to claim 59.

66. The process according to according to claim 65, wherein said introduction of the double-stranded RNA is introduction of a vector into which a complementary DNA of the RNA according to claim 62 or 63 is inserted.

67. The process according to claim 65 or 66, wherein the cell resistant to a lectin which recognizes a sugar chain in which 1-position of fucose is bound to 6-position of N-acetylglucosamine in the reducing end through α

-bond in a complex N-glycoside-linked sugar chain is a cell resistant to at least one lectin selected from the group consisting of the following (a) to (d);

(a) a Lens culinaris lectin;

(b) a Pisum sativum lectin;

(c) a Vicia faba lectin;

(d) an Aleuria aurantia lectin.

68. The process according to any one of claims 65 to 67, wherein the cell is selected from the group consisting of a yeast, an animal cell, an insect cell and a plant cell.

69. The process according to any one of claims 65 to 68, wherein the cell is selected from the group consisting of the following (a) to (j):

(a) a CHO cell derived from a Chinese hamster ovary tissue;

(b) a rat myeloma cell line YB2/3HL.P2.G11.16Ag.20 cell;

(c) a mouse myeloma cell line NS0 cell;

(d) a mouse myeloma cell line SP2/0-Ag14 cell;

(e) a BHK cell derived from a Syrian hamster kidney tissue;

(f) a hybridoma cell which produces an antibody;

(g) a human leukemic cell line Namalwa cell;

(h) an embryonic stem cell;

(i) a fertilized egg cell;

(j) a plant cell.