Mouse Minute Virus (MMV) Contamination--A Case Study: Detection, Root Cause Determination, and Corrective Actions

Area of Science:

• Biotechnology
• Virology
• Mammalian Cell Culture

Background:

• Mammalian cell culture systems are crucial for producing biologic drugs, offering advantages in yield and protein modification.
• These systems are susceptible to contamination by adventitious agents, such as Mouse Minute Virus (MMV).
• MMV contamination can be asymptomatic, affecting neither cell viability nor product titers, complicating detection.

Purpose of the Study:

• To investigate the ubiquitous threat of MMV in Chinese hamster ovary (CHO) cell-based biologic drug production.
• To identify potential sources of MMV contamination, including animal-free media components.
• To highlight the limitations of in vitro assays and the necessity of PCR for reliable MMV detection.

Main Methods:

• A case study approach was employed to examine MMV contamination in a CHO cell-based production system.
• Investigated the role of animal-free recombinant media additives as a potential contamination source.
• Utilized polymerase chain reaction (PCR) assays for sensitive and reliable detection of MMV.

Main Results:

• Mouse Minute Virus (MMV) was identified as a significant and widespread contaminant in CHO cell cultures.
• An animal-free recombinant media additive was identified as the source of MMV contamination.
• Standard in vitro virus assays failed to detect the MMV contamination, underscoring the need for PCR-based methods.

Conclusions:

• MMV contamination presents a "silent" risk in biologic manufacturing, potentially evading standard detection methods.
• Animal-free media components require rigorous screening to prevent adventitious agent contamination.
• Effective corrective and preventative actions (CAPA), including source identification and facility decontamination, are essential for resuming safe production.