Monoclonal antibodies with enhanced ADCC function
The invention concerns a method for obtaining and selecting monoclonal antibodies by an ADDC-type test, said antibodies capable of activating type III Fcy receptors and having a particular glycan structure. The inventive anti-D antibodies can be used for preventing Rhesus isoimmunization in Rh negative persons, in particular for haemolytic disease in a new-born baby of for uses such as idiopathic thrombocytopenic pupura 9ITP.
1. A cell culture, comprising an isolated clone, wherein said cell culture produces monoclonal antibodies having on the Fcγ glycosylation site (Asn 297, EU numbering) bi-antennary glycan structures,
wherein said glycan structures of the monoclonal antibodies have a fucose content less than 65%, and
wherein said glycan structures of the monoclonal antibodies have a content greater than 60% for the G0+G1+G0F+G1F forms
2. The cell culture of claim 1 , wherein the fucose content is less than 30%.
3. The cell culture of claim 1 , wherein the fucose content is between 20% and 45%.
4. The cell culture of claim 3 , wherein the fucose content is between 25% and 40%.
5. The cell culture of claim 1 , wherein the monoclonal antibodies are directed against an antigen, and activate effector cells expressing Fcγ type III receptors, causing a lysis of target cells presenting the antigen greater than 60% of a lysis caused by polyclonal antibodies directed against the antigen.
6. The cell culture of claim 5 , wherein the antigen is rhesus D.
7. The cell culture of claim 1 , wherein the monoclonal antibodies are directed against an antigen, and activate effector cells expressing Fcγ type III receptors, causing a lysis of target cells presenting the antigen greater than 90% of a lysis caused by polyclonal antibodies directed against the antigen.
8. The cell culture of claim 7 , wherein the antigen is rhesus D.
9. The cell culture of claim 1 , wherein the monoclonal antibodies are IgG1 antibodies.
10. The cell culture of claim 1 , wherein the monoclonal antibodies are IgG3 antibodies.
11. The cell culture of claim 1 , wherein said glycan structures of the monoclonal antibodies have a sialic acid content of less than 25%.
12. A cell culture, comprising an isolated clone, wherein said cell culture produces monoclonal antibodies having on the Fcγ glycosylation site (Asn 297, EU numbering) bi-antennary glycan structures,
wherein said glycan structures of the monoclonal antibodies have a content less than 50% for the G0F+G1F forms, and
wherein said glycan structures of the monoclonal antibodies have a content greater than 60% for the G0+G1+G0F+G1F forms.
13. The cell culture of claim 12 , wherein said glycan structures of the monoclonal antibodies have a content less than 30% for the G0F+G1F forms.
14. The cell culture of claim 12 , wherein said glycan structures of the monoclonal antibodies have a content greater than 80% for the G0+G1+G0F+G1F forms.
15. The cell culture of claim 12 , wherein the monoclonal antibodies are directed against an antigen, and activate effector cells expressing Fc type III receptors, causing a lysis of target cells presenting the antigen greater than 60% of a lysis caused by polyclonal antibodies directed against the antigen.
16. The cell culture of claim 15 , wherein the monoclonal antibodies cause a lysis of target cells presenting the antigen greater than 70% of a lysis caused by polyclonal antibodies directed against the antigen.
17. The cell culture of claim 16 , wherein the monoclonal antibodies cause a lysis of target cells presenting the antigen greater than 80% of a lysis caused by polyclonal antibodies directed against the antigen.
18. The cell culture of claim 17 , wherein the monoclonal antibodies cause a lysis of target cells presenting the antigen greater than 90% of a lysis caused by polyclonal antibodies directed against the antigen.
19. The cell culture of claim 12 , wherein said monoclonal antibodies are IgG1 antibodies.
20. The cell culture of claim 12 , wherein said monoclonal antibodies are IgG3 antibodies.
21. The cell culture of claim 12 , wherein said monoclonal antibodies are anti Rh(D) antibodies.
22. The cell culture of claim 12 , wherein said glycan structures of the monoclonal antibodies have a sialic acid content of less than 25%.
23. The cell culture of claim 1 , wherein the isolated clone is produced by transfection of the cell line deposited with the ATCC as accession number CRL-1662.
24. The cell culture of claim 12 , wherein the isolated clone is produced by transfection of the cell line deposited with the ATCC as accession number CRL-1662.
25. The cell culture of claim 1 , wherein the isolated clone is isolated from a cell line transfected with a gene coding for said monoclonal antibodies.
26. The cell culture of claim 12 , wherein the isolated clone is isolated from a cell line transfected with a gene coding for said monoclonal antibodies.