Method for producing proteins in
Methods for producing proteins and glycoproteins in Pichia pastoris that lack detectable cross binding activity to antibodies made against host cell antigens are described. In particular, methods are described wherein recombinant Pichia pastoris strains that do not display a β-mannosyltransferase 2 activity with respect to an N-glycan or O-glycan and do not display at least one activity selected from a β-mannosyltransferase 1, 3, and 4 activity to produce recombinant proteins and glycoproteins. These recombinant Pichia pastoris strains can produce proteins and glycoproteins that lack detectable α-mannosidase resistant β-mannose residues thereon and thus, lack cross binding activity to antibodies against host cell antigens. Further described are methods for producing bi-sialylated human erythropoietin in Pichia pastoris that lack detectable cross binding activity to antibodies against host cell antigens.
1. A method for producing a recombinant glycoprotein in Pichia pastoris host cells that lacks detectable cross binding activity with antibodies that bind immunogenic B-linked mannose residues, comprising:
(a) providing a recombinant Pichia pastoris host cell which does not display β-mannosyltransferase 2 activity with respect to an N-glycan or O-glycan and does not display at least one activity selected from β-mannosyltransferase 1 activity and β-mannosyltransferase 3 activity with respect to an N-glycan or O-glycan and which includes a nucleic acid molecule encoding the recombinant glycoprotein;
(b) growing the host cell in a medium under conditions effective for expressing the recombinant glycoprotein; and
(c) recovering the recombinant glycoprotein from the medium to produce the recombinant glycoprotein that lacks detectable cross binding activity with antibodies that bind B-linked mannose residues.
2. The method of claim 1 , wherein the host cell does not display β-mannosyltransferase 2 activity, β-mannosyltransferase 1 activity, and β-mannosyltransferase 3 activity with respect to an N-glycan or O-glycan.
3. The method of claim 1 , wherein the host cell further does not display β-mannosyltransferase 4 activity with respect to an N-glycan or O-glycan.
4. The method of claim 1 , wherein the detectable antibody cross binding activity is determined in a sandwich ELISA.
5. The method of claim 1 , wherein the detectable antibody cross binding activity is determined in a Western blot.
6. The method of claim 1 , wherein the recombinant glycoprotein is a therapeutic glycoprotein.
7. The method of claim 6 , wherein the therapeutic glycoprotein is selected from the group consisting erythropoietin (EPO); cytokines such as interferon α, interferon β, interferon γ, and interferon ω; and granulocyte-colony stimulating factor (GCSF); GM-CSF; coagulation factors such as factor VIII, factor IX, and human protein C; antithrombin III; thrombin; soluble IgE receptor α-chain; immunoglobulins such as IgG, IgG fragments, IgG fusions, and IgM; immunoadhesions and other Fc fusion proteins such as soluble TNF receptor-Fc fusion proteins; RAGE-Fc fusion proteins; interleukins; urokinase; chymase; and urea trypsin inhibitor; IGF-binding protein; epidermal growth factor; growth hormone-releasing factor; annexin V fusion protein; angiostatin; vascular endothelial growth factor-2; myeloid progenitor inhibitory factor-I; osteoprotegerin; α-1-antitrypsin; α-feto proteins; DNase II; kringle 3 of human plasminogen; glucocerebrosidase; TNF binding protein 1; follicle stimulating hormone; cytotoxic T lymphocyte associated antigen 4—Ig; transmembrane activator and calcium modulator and cyclophilin ligand; glucagon like protein 1; and IL-2 receptor agonist.
8. The method of claim 1 , wherein the host cell is genetically engineered to produce glycoproteins that have human-like N-glycans.
9. The method of claim 1 , wherein the host cell is genetically engineered to produce glycoproteins that have predominantly an N-glycan selected from Man 5 GlcNAc 2 , Man 3 GlcNAc 2 , GlcNAcMan 5 GlcNAc 2 , GalGlcNAcMan 5 GlcNAc 2 , NANAGalGlcNAcMan 5 GlcNAc 2 , GlcNAcMan 3 GlcNAc 2 , GlcNAc (1-4) Man 3 GlcNAc 2 , Gal (1-4) GlcNAc (1-4) Man 3 GlcNAc 2 , and NANA (1-4) Gal (1-4) GlcNAc (1-4) Man 3 GlcNAc 2 .
10. A composition comprising one or more recombinant glycoproteins obtained by the method of claim 1 .