Efficient production of F(ab')2 fragments in mammalian cells

A process for producing a F(ab′)2 fragment by recombinant expression from a cell in a ratio of at least 1:1 with the corresponding F(ab′) fragment, the process comprising the steps of:

• providing a cell deposited at the European Collection of Cell Cultures (“ECACC”) under number 96022940, said cell further comprising:
• one or more nucleic acids comprising sequences capable of driving expression operably linked to nucleotide sequences encoding F(ab′)2 fragments;
• culturing the cell in a suitable medium;
• and
• expressing the one or more nucleic acids to produce from the cell the F(ab′)2 fragment, wherein the F(ab′)2 fragment and the corresponding F(ab′) fragment are secreted from the cell in a ratio of at least 1:1.

A method for improving the ratio of expressed F(ab′)2 fragments to F(ab′) fragments by recombinant expression from cells as compared to expression from Chinese Hamster Ovary (CHO) cells, the process comprising:

• providing a cell having one or more recombinant nucleic acids comprising sequences capable of driving expression operably linked to nucleotide sequences encoding F(ab′)2 fragments;
• culturing the cell in a suitable medium;
• and
• expressing the one or more nucleic acids to produce from the cell the F(ab′)2 fragment, wherein the cell is a cell deposited at the European Collection of Cell Cultures (“ECACC”) under number 96022940, said cell further comprising the one or more recombinant nucleic acids.