Purification of oncolytic measles virus by cation-exchange chromatography using resin-based stationary phases
Dustin Eckhardt, Hauke Dieken, Daniel Loewe, Tanja A. Grein, Denise Salzig, Peter Czermak
Abstract
Cancer therapy with oncolytic measles virus (MV) requires high titers of pure, infectious virus particles (~108 times more particles per dose than the measles vaccine). A gentle but efficient downstream purification process is therefore essential. Here we investigated the suitability of ion-exchange chromatography for the purification of MV using resin-based stationary phases. The success of purification was evaluated based on the infectious virus yield, the ratio of infectious to total MV particles, and the quantity of major contaminants (host cell DNA and total protein). After testing different anion-exchange, cation-exchange and hybrid materials, we found that the cation-exchanger Eshmuno ® CPX (Merck) was the most promising resin. By optimizing the pH of the feed and buffers, and reducing the flow rate, we achieved a yield of 80.7% infectious MV particles while reducing the ratio of infectious to total MV particles by only 16.8%. We also removed 98.3% of the total protein and 80.5% of the host cell DNA. Although resin-based chromatography is not yet typically used for virus purification, we have developed a promising new approach to improve the efficiency of MV purification during downstream processing.