Method of expressing galactosyltransferase and inhibiting xylosyltransferase or fucosyltransferase in a transgenic plant cell for secretory production of glycoproteins having human-type sugar chains
A method for the secretory production of a glycoprotein having a human-type sugar chain, comprising a step of introducing a gene of an enzyme capable of performing a transfer reaction of a galactose residue to a non-reducing terminal acetylglucosamine residue, and a gene of heterologous glycoprotein, to obtain a transformed plant cell, a step of culturing the plant cell, and a step of recovering the culture medium of the plant cell.
1. A method for producing a secretory glycoprotein having a human-type sugar chain from a transgenic plant cell, the method comprising:
providing a transgenic plant cell that comprises a first heterologous nucleic acid sequence encoding a β1,4-galactosyltransferase and a second heterologous nucleic acid sequence encoding a glycoprotein that is heterologous to the plant cell, wherein in the transgenic plant cell, the expression of an endogenous β1,2-xylosyltransferase, α1,3-fucosyltransferase, or both is inhibited or a gene encoding the endogenous β1,2-xylosyltransferase or α1,3-focosyltransferase is mutated; and
culturing the transgenic plant cell in a culture medium to allow production and secretion of the glycoprotein, which contains an N-glycan having a galactose residue linked to a non-reducing terminal acetylglucosamine residue; and
collecting the culture medium for isolation of the glycoprotein.
2. The method of claim 1 , further comprising recovering the glycoprotein from the culture medium.
3. The method of claim 1 , wherein the transgenic plant cell has the endogenous gene encoding the β1,2-xylosyltransferase or the endogenous α1,3-fucosyltransferase inactivated.
4. The method of claim 1 , wherein the transgenic plant cell has the endogenous genes encoding both the β1,2-xylosyltransferase and the α1,3-fucosyltransferase inactivated.
5. The method of claim 1 , wherein the culture medium comprises an agent that increases the concentration of the glycoprotein in the culture medium.
6. The method of claim 5 , wherein the agent is polyvinylpyrrolidone (PVP).
7. The method of claim 5 , wherein the culture medium further comprises a protease inhibitor.
8. The method of claim 1 , wherein the transgenic plant cell is in a cultured plant tissue, a cultured plant organ, or a whole plant.
9. The method of claim 1 , wherein the transgenic plant cell is a cell of Solanaceae, Gramineae, Cruciferae, Rosaceae, Leguminosae, Cucurbitaceae, Labiatae, Liliaceae, Chenopodiaceae, or Umbelliferae.
10. The method of claim 9 , wherein the transgenic plant cell is a tobacco cell.
11. The method of claim 1 , wherein the heterologous glycoprotein is an enzyme, a hormone, a cytokine, an antibody, a vaccine antigen, a receptor, or a serum protein.
12. The method of claim 1 , wherein the providing step is performed by:
introducing into a plant cell the first heterologous nucleic acid sequence and the second heterologous nucleic acid sequence, and inactivating the endogenous β1,2-xylosyltransferase, α1,3-fucosyltransferase, or both in the plant cell; thereby producing the transgenic plant cell.
13. The method of claim 12 , wherein the inactivating step is performed by chemical mutagenesis, site-directed mutagenesis, or a tagging method to inactivate the gene encoding the β1,2-xylosyltransferase or α1,3-focusyltransferase.