Biotechnology

Biography

Biography: Hauke Dieken

Abstract

Cancer still remains a major global health burden with 8.7 million related deaths in 2015. A novel therapy concept, which achieved full remission of even advanced-stage cancer, is engineered oncolytic measles virus (OMV). To ensure an effective cancer lysis, extremely high doses of at least 10⁸-10¹¹ TCID₅₀ (50% tissue culture infectious dose) of infective OMV particles are necessary. Furthermore, the OMV must be extremely pure. Impurities like host cell proteins (HCP), host cell DNA (hcDNA) or non-infective viral fragments must be reduced below the regulatory limits.

An upstream process for high titer OMV production has already been established in our lab and we are currently focusing on the development of an efficient chromatographic downstream process.

We first characterized the OMV’s size distribution, isoelectric point and physicochemical stability. Based on these characteristics, we tested different cationic and hydrophobic interaction resins. We found that a two-step purification process which combined cation exchange chromatography flowed by hydrophobic interaction chromatography leads to high yield of infectious OMV (~70%) and strong reduction of HCP (~98%) as well as hcDNA (~80%). The tested resin-stationary phases were beneficial over monolithic stationary phases which only led to average yields for OMV. Our findings are contrary to the common scientific opinion which assesses resin-based phases as unsuitable for virus purification processes. Nonetheless, we showed that it is worth to investigate resin-based stationary phases also for larger particle such as OMV and that resin-based stationary phases are a versatile option to reach highest OMV yield, purity and potency.