Vero cell

Vero cell. Vero cells are a lineage of cells derived from the kidney epithelium of an African green monkey (Chlorocebus sabaeus). They were first isolated in 1962 by Yasumura Y. and Kawakita Y. at the Chiba University in Japan. This continuous cell line is characterized by its robust growth, susceptibility to a wide range of viruses, and lack of interferon production, making it invaluable in biomedical research and industrial biotechnology.

History and origin

The lineage was established in 1962 from the kidney tissue of a normal adult female African green monkey, a species native to regions like Ethiopia and Senegal. The name "Vero" is derived from an abbreviation of "Verda Reno," which means "green kidney" in Esperanto. The isolation work at Chiba University was part of broader international efforts, contemporaneous with other significant cell line developments like HeLa cells. Their initial characterization demonstrated an unusual stability and an absence of certain viral particles that were common in other primate cell lines of the era, such as those from rhesus macaques. This clean profile facilitated their rapid adoption by institutions like the World Health Organization and the National Institutes of Health for virus propagation studies.

Characteristics and culture

Vero cells are considered a fibroblast-like cell line that adheres to surfaces like polystyrene or glass in standard culture conditions. A key genetic characteristic is that they are considered "aneuploid", possessing an abnormal number of chromosomes. They are highly susceptible to infection by many RNA and DNA viruses, including poliovirus, influenza virus, and adenovirus. Notably, they have a functional deficiency in the interferon signaling pathway, which allows viruses to replicate without triggering this major innate immune defense. They can be cultured in media such as Dulbecco's Modified Eagle Medium supplemented with fetal bovine serum, and they are amenable to growth in large-scale bioreactors like those used by Novartis or Sanofi.

Applications in research and vaccine production

Their primary application is in the field of virology for the isolation, propagation, and study of viral pathogens, including rabies virus, dengue virus, and the Zaire ebolavirus. Industrially, Vero cells are a critical substrate for the production of many licensed human vaccines. This includes vaccines for poliomyelitis (inactivated polio vaccine), rotavirus (e.g., Rotarix), and more recently, vaccines against SARS-CoV-2 like Covishield and Janssen. The cells are also used in toxicology testing for products like botulinum toxin and in basic research areas such as carcinogenesis and parasitology, including studies on malaria.

Safety considerations and regulatory aspects

As a non-human primate cell line, a primary safety concern is the potential presence of adventitious agents, such as latent simian viruses. Rigorous screening for contaminants like simian virus 40 is mandated by regulatory bodies including the U.S. Food and Drug Administration and the European Medicines Agency. The use of Vero cells for vaccine manufacturing must comply with guidelines from the World Health Organization and the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. Master cell banks are thoroughly characterized to ensure consistency and safety for human use in products distributed globally.

Related cell lines and variants

Several derivative cell lines have been developed to enhance specific properties. The Vero E6 clone is particularly susceptible to viruses like SARS-CoV-1 and is widely used in biosafety level 3 laboratories. Other variants include Vero 76 and Vero C1008, which was used to develop the World Health Organization-approved MRC-5 cell line for viral vaccine production. These related lines are often compared to other continuous cell lines used in virology, such as HEK 293 cells, MDCK cells, and BHK-21 cells, each selected for specific viral tropisms or production efficiencies. Category:Cell lines Category:Virology Category:Vaccines