INFUSION CLONING, EXPRESSION AND PURIFICATION OF THE RECOMBINANT RITUXIMAB PRODUCED IN CHO CELLS

Abstract

Rituximab is a crucial chimeric monoclonal antibody (mAb) used in the treatment of B-cell lymphomas, leukemia’s, and certain autoimmune diseases. The process to identify the antibody gene, cloning and developing cell lines is a tedious, time consuming and costly process. Since, Rituximab effectively and specifically binds to CD20, it is important to develop faster and more affordable production method for this mAb. In this work, we have developed infusion based sequential cloning of light chain (LC) and heavy chain (HC) of Rituximab into a single expression vector followed by transfection of CHO-S cells. Fed-Batch analysis was performed to choose stable clone for the production of Rituximab. The Rituximab produced by the top two shortlisted clones was purified via affinity chromatography using an automated system with mAb Select Prism A resin. The resulting purified Rituximab was then characterized for size and charge variants using chromatographic methods, and its molecular weight (145 kDa) was confirmed through mass spectrometry studies.