Abstract

Efficiency of Baculovirus Clearance Methods from Biopharmaceuticals

Author(s): Mohammad Reza Sadrzadeh, Mohsen Dehghani, Parisa Hashemi, Ehsan Seyedjafari*

Viral clearance study is necessary to assure biological products to be free of viruses either introduced into the product via biological raw materials or adventitiously, and for conforming with continuously stricter rules of health authorities. As insect cell–baculovirus expression system has been considered as a powerful workhorse for recombinant protein production and is being harnessed in industrial manufacturing of several of biopharmaceuticals including HPV vaccine, Influenza vaccine and a prostate cancer immunotherapy, assurance of baculovirus removal from the final product is necessary as a relevant virus whose presence in the bioprocess is known. Hence, investigating ways of removal or inactivation of baculovirus for their incorporation in the manufacturing process is a fundamental step toward reaching that goal. Removal of baculovirus by anion exchange and mixed-modal chromatography and also by filtration through virus filters and its inactivation by UV-C, 2-ME, H₂O₂, low pH, high pH and pasteurization are considered in this research. Furthermore, as viral clearance study is process dependent, removal and inactivation of baculovirus has also been investigated in a human papillomavirus vaccine downstream process consisting of a hypotonic lysis of harvested cells, chromatography steps, virus filtration and ultrafiltration. Removal and inactivation of baculovirus is assessed by qPCR and TCID50 respectively. pasteurization treatment produced the highest level of inactivation with 5.87 LRV followed by H₂O₂, low pH, Triton X-100, 2-ME, UV-C with 5.58 4.33, 3.62, 3.58 and 2.58 LRVs respectively. High pH resulted in a negligible inactivation. DMAE chromatography, Viresolve virus filter and CHTII chromatography resulted in 4.90, 4.64 and 3.90 LRV respectively.