Details

Autor(en) / Beteiligte

• Shimode, Sayumi
• Sakuma, Tetsushi
• Yamamoto, Takashi
• Miyazawa, Takayuki

Titel

Establishment of CRFK cells for vaccine production by inactivating endogenous retrovirus with TALEN technology

Ist Teil von

• Scientific reports, 2022-04, Vol.12 (1), p.6641-6641, Article 6641

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2022

Quelle

MEDLINE

Beschreibungen/Notizen

• Endogenous retroviruses (ERVs) are retroviral sequences present in the host genomes. Although most ERVs are inactivated, some are produced as replication-competent viruses from host cells. We previously reported that several live-attenuated vaccines for companion animals prepared using the Crandell-Rees feline kidney (CRFK) cell line were contaminated with a replication-competent feline ERV termed RD-114 virus. We also found that the infectious RD-114 virus can be generated by recombination between multiple RD-114 virus-related proviruses (RDRSs) in CRFK cells. In this study, we knocked out RDRS env genes using the genome-editing tool TAL Effector Nuclease (TALEN) to reduce the risk of contamination by infectious ERVs in vaccine products. As a result, we succeeded in establishing RDRS knockout CRFK cells (RDKO_CRFK cells) that do not produce infectious RD-114 virus. The growth kinetics of feline herpesvirus type 1, calicivirus, and panleukopenia virus in RDKO_CRFK cells differed from those in parental cells, but all of them showed high titers exceeding 10 7 TCID 50 /mL. Infectious RD-114 virus was undetectable in the viral stocks propagated in RDKO_CRFK cells. This study suggested that RDRS env gene-knockout CRFK cells will be useful as a cell line for the manufacture of live-attenuated vaccines or biological substances with no risk of contamination with infectious ERV .