Development of apoptosis-resistant CHO cell line expressing PyLT for the enhancement of transient antibody production

In an effort to improve transient gene expression (TGE) in Chinese hamster ovary (CHO) cells, the combinatorial engineering of polyoma virus large T-antigen (PyLT) and Bcl-x(L) in CHO DG 44 cells was performed. The developed cell line (CHOP-off-Bcl-x(L)), which constitutively expresses PyLT and inducibly expresses Bcl-x(L), is capable of episomal replication with the use of the DNA expression vector encoding PyOri, EBNA-1, and OriP (pWP-Ang-EBNA/OriP-PyOri) and it is apoptosis-resistant. When the recombinant antibody was transiently expressed, this combinatorial engineering in the CHO cells resulted in a more than twofold increase in the product titer in various culture conditions such as batch, fed-batch, and cultures with sodium butyrate additions. Taken together, the data obtained here demonstrate that the use of the CHOP-off-Bcl-xL cell line can enhance the TGE significantly, which facilitates early stage product development in the pharmaceutical industry. (C) 2012 Elsevier Ltd. All rights reserved.