Construction of High Expression Vector System Producing Therapeutic Monoclonal Antibody Through Incorporation of Matrix Attachment Region Element: A Preliminary Report

ABSTRACT

The emergence of monoclonal antibody specific to human growth factor receptor marked the greatest achievement in human fight against cancer. By utilizing a specific antibody, cancer treatment nowadays is getting more specific and efficient. Despite its achievement, the main drawback of antibody therapy remains at its production level. Low yield and transient expression of antibody by mammalian host cells are among the problems discovered during antibody production. Many strategies have been implied to increase yield and stability of protein including improvement of vector expression system with DNA elements integration as well as manipulating the bioreactor environment to increase cell density and attain more products. Our study is currently focused on constructing a high expression vector system using matrix attachment region (MAR) element in targeted therapeutic monoclonal antibody production. In this study, a nuclear halo formation has been successfully optimized for CHO cells. A minimum time of 8 minutes is required for maximum nuclear halo formation, thus exposing the most significant sites containing MAR element in CHO genome. This preliminary step is crucial due to the fact that the nuclear halo formation and MAR elements isolation are specific for different types of cells. Subsequent works are currently being carried out to isolate the MAR element from CHO cells based on the time determined from nuclear halo formation. This work is going to be distinctive from previous studies as the MAR element will be predicted from the host cells genome. The mechanism of which the integrated functional MAR element can increase the antibody production even at random position is through up-regulation of gene transcription by adopting a DNA loop structure of nucleosomes that open the structure for specific transcription factor binding.

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