Methods for producing stabilized human IgG2 and IgG3 antibodies
View Patent ↗It is intended to provide highly stable variants of human antibody IgG2 and IgG3 subclasses. The present invention provides an IgG heavy chain comprising the constant region of a human IgG2 heavy chain having at least a substitution of Y for F at the 300th position, L for V at the 309th position, or A for T at the 339th position designated by the EU index of Kabat et al. and an IgG heavy chain comprising the constant region of a human IgG3 heavy chain having at least a substitution of K for N at the 392nd position or V for M at the 397th position designated by the EU index of Kabat et al. The present invention also provides monoclonal antibodies comprising these heavy chains.
1. A method for producing a monoclonal antibody comprising the step of: culturing, in a culture solution, a host comprising an expression vector having polynucleotides encoding the heavy and light chains of a monoclonal antibody comprising an isolated and non-naturally occurring IgG antibody comprising:
(1) the constant region of a human IgG2 heavy chain having Y at the 300th position designated by the EU index of Kabat et al.;
(2) the constant region of a human IgG2 heavy chain having L at the 309th position designated by the EU index of Kabat et al.; or
(3) the constant region of a human IgG2 heavy chain having A at the 339th position designated by the EU index of Kabat et al.; and
obtaining a monoclonal antibody from the resulting cultures and/or the host.
2. A method for suppressing monoclonal antibody aggregation, characterized by comprising substituting Y for F at the 300th position designated by the EU index of Kabat et al. in the constant region of a human IgG2 heavy chain.
3. A method for suppressing monoclonal antibody aggregation, characterized by comprising substituting L for V at the 309th position designated by the EU index of Kabat et al. in the constant region of a human IgG2 heavy chain.
4. A method for suppressing monoclonal antibody aggregation, characterized by comprising substituting A for T at the 339th position designated by the EU index of Kabat et al. in the constant region of a human IgG2 heavy chain.
5. A method for producing a monoclonal antibody, comprising the step of: culturing, in a culture solution, a host comprising an expression vector having polynucleotides encoding the heavy and light chains of a monoclonal antibody comprising an isolated and non-naturally occurring IgG antibody comprising the constant region of a human IgG3 heavy chain having V at the 397th position designated by the EU index of Kabat et al.; and obtaining a monoclonal antibody from the resulting cultures and/or the host.
6. A method for suppressing monoclonal antibody aggregation, characterized by comprising substituting K for N at the 392nd position designated by the EU index of Kabat et al. in the constant region of a human IgG3 heavy chain.
7. A method for suppressing monoclonal antibody aggregation, characterized by comprising substituting V for M at the 397th position designated by the EU index of Kabat et al. in the constant region of a human IgG3 heavy chain.
8. The method of claim 1 , wherein the constant region of the human IgG2 heavy chain of (1) to (3) further has S at the 331st position designated by the EU index of Kabat et al.